Common use of Trust Clause in Contracts

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 2-CB-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 Class 2-CB-1 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 Principal Balance as of the Cut-Off Date: $24,424,200.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 24-CB-1 CB Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 29,539,800.00 Class 24-CB-1 CB Certificate Interest Rate: 5.5007.000% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 24-CB-1 CB Principal Balance as of the Cut-Off Date: $24,424,200.00 29,539,800.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BV3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 X Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 21-CB-1 A-8 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 4,215,000.00 Class 21-CB-1 A-8 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August September 25, 2035 Class 21-CB-1 A-8 Principal Balance as of the Cut-Off Date: $24,424,200.00 4,215,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BL5 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-1 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 21-CB-1 A-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 59,304,107.00 Class 21-CB-1 A-4 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August September 25, 2035 Class 21-CB-1 A-4 Principal Balance as of the Cut-Off Date: $24,424,200.00 59,304,107.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BG6 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 21-CB-2 A-5 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended, together with certain rights specified in the Pooling Agreement. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 21-CB-1 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 50,000,000.00 Class 21-CB-1 A-2 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August September 25, 2035 Class 21-CB-1 A-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 50,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BE1 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 23-CB-1 CB Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 37,805,200.00 Class 23-CB-1 CB Certificate Interest Rate: 5.5006.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 23-CB-1 CB Principal Balance as of the Cut-Off Date: $24,424,200.00 37,805,200.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BU5 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 24-CB-2 CB Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 21-CB-1 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 13,552,800.00 Class 21-CB-1 A-1 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August September 25, 2035 Class 21-CB-1 A-1 Principal Balance as of the Cut-Off Date: $24,424,200.00 13,552,800.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BD3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 13,411,848.00 Class 2-CB-1 X Certificate Interest Rate: 5.500% 5.750%, applied to the Class X Notional Amount Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 X Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class X Notional Amount as of the Cut-Off Date: $13,411,848.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 JF0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 P Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 21-CB-1 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 16,001,326.00 Class 21-CB-1 A-5 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August September 25, 2035 Class 21-CB-1 A-5 Principal Balance as of the Cut-Off Date: $24,424,200.00 16,001,326.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BH4 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 2-CB-1 CB-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 41,289,416.00 Class 2-CB-1 CB-6 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 CB-6 Principal Balance as of the Cut-Off Date: $24,424,200.00 41,289,416.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BS0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-7 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 2-CB-1 CB-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 31,022,740.00 Class 2-CB-1 CB-5 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 CB-5 Principal Balance as of the Cut-Off Date: $24,424,200.00 31,022,740.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BR2 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-6 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 2C-CB-1 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 14,369,296.00 Class 2C-CB-1 X Certificate Interest Rate: 5.500% %, applied to the Class C-X Notional Amount Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August September 25, 2035 Class 2C-CB-1 X Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class C-X Notional Amount as of the Cut-Off Date: $14,369,296.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BW1 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 P Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 2-CB-1 CB-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 149,937,994.00 Class 2-CB-1 CB-3 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 CB-3 Principal Balance as of the Cut-Off Date: $24,424,200.00 149,937,994.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BP6 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-4 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 2-CB-2 Certificates will provide credit support to other Classes of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 Portion of the Class 2-CB-1 CB-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 4,195,000.00 Class 2-CB-1 CB-2 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 CB-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 4,195,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BN1 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-3 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 Portion of the Class 21-CB-1 A-7 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 1,000,000.00 Class 21-CB-1 A-7 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August September 25, 2035 Class 21-CB-1 A-7 Principal Balance as of the Cut-Off Date: $24,424,200.00 1,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BK7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 21-CB-2 A-8 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 Portion of the Class 2-CB-1 CB-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 31,569,066.00 Class 2-CB-1 CB-4 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 CB-4 Principal Balance as of the Cut-Off Date: $24,424,200.00 31,569,066.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 BQ4 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-5 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26July 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 6 Portion of the Class 2-CB-1 Principal Balance A-6 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 39,531,000.00 Class 2-CB-1 A-6 Certificate Interest Rate: 5.500% Variable, applied to the Class 2-A-6 Notional Amount Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 A-6 Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class 2-A-6 Notional Amount as of the Cut-Off Date: $39,531,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 92922F Y7 7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August April 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 3 Portion of the Class 21-CB-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 39,748,000.00 Class 21-CB-1 Certificate Interest Rate: 5.500% Cut-Off Date: August April 1, 2005 First Distribution Date: September 26May 25, 2005 Last Scheduled Distribution Date: August May 25, 2035 Class 21-CB-1 Principal Balance as of the Cut-Off Date: $24,424,200.00 39,748,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 4Z 3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 21-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26February 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 1 Portion of the Class 27-CB-1 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 1,732,000.00 Class 27-CB-1 A-2 Certificate Interest Rate: 5.500% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: August March 25, 2035 Class 27-CB-1 A-2 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 1,732,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 2U 6 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 27-CB-2 A-3 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 2-CB-1 Principal Balance CB-4 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 154,500,000.00 Class 2-CB-1 CB-4 Certificate Interest Rate: 5.500% Variable, applied to the Class CB-4 Notional Amount Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 2-CB-1 CB-4 Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class CB-4 Notional Amount as of the Cut-Off Date: $154,500,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 5Z 2 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-5 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 A-8 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 15,000,700.00 Class 2-CB-1 A-8 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-8 Principal Balance as of the Cut-Off Date: $24,424,200.00 15,000,700.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 JD5 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 2D-CB-1 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 606,014.00 Class 2D-CB-1 X Certificate Interest Rate: 5.500% applied to the Class D-X Notional Amount Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 2020 Class 2D-CB-1 X Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class D-X Notional Amount as of the Cut-Off Date: $606,014.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 7D 9 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 P Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 2-CB-1 CB-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 500,000.00 Class 2-CB-1 CB-6 Certificate Interest Rate: 5.500% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 2-CB-1 CB-6 Principal Balance as of the Cut-Off Date: $24,424,200.00 500,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6B 4 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-7 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26March 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 2 Portion of the Class 21-CB-1 A-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 281,002,000.00 Class 21-CB-1 A-4 Certificate Interest Rate: 5.500% Variable, applied to the Class 1-A-4 Notional Amount Cut-Off Date: August March 1, 2005 First Distribution Date: September 26April 25, 2005 Last Scheduled Distribution Date: August April 25, 2035 Class 21-CB-1 A-4 Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class 1-A-4 Notional Amount as of the Cut-Off Date: $281,002,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 3M 3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 21-CB-2 A-5 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26October 27, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 9 Portion of the Class 25-CB-1 A-9 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 4,937,000.00 Class 25-CB-1 A-9 Certificate Interest Rate: 5.500% Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: August November 25, 2035 Class 25-CB-1 A-9 Principal Balance as of the Cut-Off Date: $24,424,200.00 4,937,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 FN7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 X Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26March 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 1-A-5 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 2 Portion of the Class 21-CB-1 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 14,790,000.00 Class 21-CB-1 A-5 Certificate Interest Rate: 5.500% Cut-Off Date: August March 1, 2005 First Distribution Date: September 26April 25, 2005 Last Scheduled Distribution Date: August April 25, 2035 Class 21-CB-1 A-5 Principal Balance as of the Cut-Off Date: $24,424,200.00 14,790,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 3N 1 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 21-CB-2 A-6 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26February 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 1 Portion of the Class 25-CB-1 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 58,645,000.00 Class 25-CB-1 A-1 Certificate Interest Rate: 5.5006.000% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: August March 25, 2035 Class 25-CB-1 A-1 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 58,645,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 2P 7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26November 29, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 10 Portion of the Class 2-CB-1 A-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 35,454,950.00 Class 2-CB-1 A-6 Certificate Interest Rate: 5.500% Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: August November 25, 2035 Class 2-CB-1 A-6 Principal Balance as of the Cut-Off Date: $24,424,200.00 35,454,950.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 GF3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 25-CB-1 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 18,433,000.00 Class 25-CB-1 A-1 Certificate Interest Rate: 5.500% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 25-CB-1 A-1 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 18,433,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6S 7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26November 29, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 10 Portion of the Class 2-CB-1 A-8 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 35,454,950.00 Class 2-CB-1 A-8 Certificate Interest Rate: 5.5006.000% Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: August November 25, 2035 Class 2-CB-1 A-8 Principal Balance as of the Cut-Off Date: $24,424,200.00 35,454,950.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 GH9 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26July 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 6 Portion of the Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 46,775,666.00 Class 2-CB-1 A-2 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 46,775,666.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 92922F Y3 6 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 2C-CB-1 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 32,170,450.00 Class 2C-CB-1 X Certificate Interest Rate: 5.500% applied to the Class C-X Notional Amount Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 2C-CB-1 X Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class C-X Notional Amount as of the Cut-Off Date: $32,170,450.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 7C 1 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2D-CB-2 X Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26July 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 6 Portion of the Class 23-CB-1 CB Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 96,253,000.00 Class 23-CB-1 CB Certificate Interest Rate: 5.500% Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 23-CB-1 CB Principal Balance as of the Cut-Off Date: $24,424,200.00 96,253,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 92922F Z4 3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 X Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26July 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 6 Portion of the Class 2-CB-1 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 44,055,000.00 Class 2-CB-1 A-1 Certificate Interest Rate: 5.500% Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 A-1 Principal Balance as of the Cut-Off Date: $24,424,200.00 44,055,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 92922F Y2 8 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26October 27, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 9 Portion of the Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 106,010,500.00 Class 2-CB-1 A-2 Certificate Interest Rate: 5.500% Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: August November 25, 2035 Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 106,010,500.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 EP3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August April 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 3 Portion of the Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 34,500,000.00 Class 2-CB-1 A-2 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August April 1, 2005 First Distribution Date: September 26May 25, 2005 Last Scheduled Distribution Date: August May 25, 2035 Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 34,500,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 5G 4 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26February 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 1 Portion of the Class 21-CB-1 A-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 13,935,000.00 Class 21-CB-1 A-4 Certificate Interest Rate: 5.500% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: August March 25, 2035 Class 21-CB-1 A-4 Principal Balance as of the Cut-Off Date: $24,424,200.00 13,935,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 2H 5 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 21-CB-2 A-5 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 2-CB-1 CB-9 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 30,000,000.00 Class 2-CB-1 CB-9 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 2-CB-1 CB-9 Principal Balance as of the Cut-Off Date: $24,424,200.00 30,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6E 8 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-10 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26November 29, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 10 Portion of the Class 24-CB-1 Principal Balance CB-4 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 117,923,200.00 Class 24-CB-1 CB-4 Certificate Interest Rate: 5.500% Variable, applied to the Class 4-CB-4 Notional Amount Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: August December 25, 2035 Class 24-CB-1 CB-4 Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class 4-CB-4 Notional Amount as of the Cut-Off Date: $117,923,200.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 GQ9 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 24-CB-2 CB-5 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class A-9 Certificates will provide credit support to certain Classes of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 A-9 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 7,330,000.00 Class 2-CB-1 A-9 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-9 Principal Balance as of the Cut-Off Date: $24,424,200.00 7,330,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 JE3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.CERTIFICATE

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26February 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 1 Portion of the Class 24-CB-1 A Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 25,283,300.00 Class 24-CB-1 A Certificate Interest Rate: 5.500% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: August March 25, 2035 2020 Class 24-CB-1 A Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 25,283,300.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 2N 2 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26November 29, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 10 Portion of the Class 2-CB-1 Principal Balance A-4 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 73,950,000.00 Class 2-CB-1 A-4 Certificate Interest Rate: 5.500% Variable, applied to the Class 2-A-4 Notional Amount Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: August November 25, 2035 Class 2-CB-1 A-4 Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class 2-A-4 Notional Amount as of the Cut-Off Date: $73,950,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 GD8 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26March 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 2 Portion of the Class 2-CB-1 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 2,225,000.00 Class 2-CB-1 A-5 Certificate Interest Rate: 5.500% Cut-Off Date: August March 1, 2005 First Distribution Date: September 26April 25, 2005 Last Scheduled Distribution Date: August April 25, 2035 Class 2-CB-1 A-5 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 2,225,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 3U 5 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26July 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 6 Portion of the Class 2-CB-1 A-7 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 43,197,000.00 Class 2-CB-1 A-7 Certificate Interest Rate: 5.500% Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 A-7 Principal Balance as of the Cut-Off Date: $24,424,200.00 43,197,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 92922F Y8 5 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26July 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 6 Portion of the Class 2C-CB-1 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 15,921,449.00 Class 2C-CB-1 X Certificate Interest Rate: 5.500% %, applied to the Class C-X Notional Amount Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2C-CB-1 X Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class C-X Notional Amount as of the Cut-Off Date: $15,921,449.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 92922F Z3 5 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 P Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 30,000,000.00 Class 2-CB-1 A-5 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-5 Principal Balance as of the Cut-Off Date: $24,424,200.00 30,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 JA1 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 A-6 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26October 27, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 5-A-2 Certificates will provide credit support to other Classes of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 25-CB-1 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 1,000,000.00 Class 25-CB-1 A-2 Certificate Interest Rate: 5.500% Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: August November 25, 2035 Class 25-CB-1 A-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 1,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 FD9 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 25-CB-2 A-3 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26February 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 1 Portion of the Class 21-CB-1 A-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 29,036,000.00 Class 21-CB-1 A-3 Certificate Interest Rate: 5.500% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: August March 25, 2035 Class 21-CB-1 A-3 Principal Balance as of the Cut-Off Date: $24,424,200.00 29,036,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 2G 7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 21-CB-2 A-4 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 A-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 53,263,000.00 Class 2-CB-1 A-3 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-3 Principal Balance as of the Cut-Off Date: $24,424,200.00 53,263,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 HY1 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 2-CB-1 CB-13 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 107,250,000.00 Class 2-CB-1 CB-13 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 2-CB-1 CB-13 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 107,250,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6J 7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-14 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 25-CB-1 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 36,000,000.00 Class 25-CB-1 A-5 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 25-CB-1 A-5 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 36,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6W 8 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26January 29, 20052007. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 20052007-7 1 Portion of the Class 2C-CB-1 P Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 1,241,772.00 Class 2C-CB-1 P Certificate Interest Rate: 5.5000.000% Cut-Off Date: August January 1, 2005 2007 First Distribution Date: September February 26, 2005 2007 Last Scheduled Distribution Date: August February 25, 2035 2037 Class 2C-CB-1 P Principal Balance as of the Cut-Off Date: $24,424,200.00 1,241,772.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 00000XXX0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another trust that owns a pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26February 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 1 Portion of the Class 27-CB-1 A-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 5,024,800.00 Class 27-CB-1 A-3 Certificate Interest Rate: 5.500% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: August March 25, 2035 Class 27-CB-1 A-3 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 5,024,800.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 2V 4 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 27-CB-2 A-4 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 A-7 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 72,000,000.00 Class 2-CB-1 A-7 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-7 Principal Balance as of the Cut-Off Date: $24,424,200.00 72,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 JC7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August April 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 3 Portion of the Class 2-CB-1 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 2,614,000.00 Class 2-CB-1 A-5 Certificate Interest Rate: 5.500% Cut-Off Date: August April 1, 2005 First Distribution Date: September 26May 25, 2005 Last Scheduled Distribution Date: August May 25, 2035 Class 2-CB-1 A-5 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 2,614,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 5K 5 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26January 29, 20052007. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 1-A-2 Certificates will provide credit support to certain Classes of Certificates, as described in the Pooling Agreement. WMALT Series 20052007-7 1 Portion of the Class 21-CB-1 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 5,558,700.00 Class 21-CB-1 A-2 Certificate Interest Rate: 5.5006.000% Cut-Off Date: August January 1, 2005 2007 First Distribution Date: September February 26, 2005 2007 Last Scheduled Distribution Date: August February 25, 2035 2037 Class 21-CB-1 A-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 5,558,700.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 00000XXX0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another trust that owns a pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26November 29, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 10 Portion of the Class 24-CB-1 CB-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 5,696,525.00 Class 24-CB-1 CB-5 Certificate Interest Rate: 5.5006.000% Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: August December 25, 2035 Class 24-CB-1 CB-5 Principal Balance as of the Cut-Off Date: $24,424,200.00 5,696,525.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 GR7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 24-CB-2 CB-6 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 2-CB-1 Principal Balance CB-2 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 305,066,700.00 Class 2-CB-1 CB-2 Certificate Interest Rate: 5.500% Variable, applied to the Class CB-2 Notional Amount Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 2-CB-1 CB-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class CB-2 Notional Amount as of the Cut-Off Date: $305,066,700.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 5X 7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-3 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26October 27, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 9 Portion of the Class 24-CB-1 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 11,448,000.00 Class 24-CB-1 A-1 Certificate Interest Rate: 5.500% Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: August November 25, 2035 Class 24-CB-1 A-1 Principal Balance as of the Cut-Off Date: $24,424,200.00 11,448,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 EX6 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 24-CB-2 A-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26February 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 1 Portion of the Class 2C-CB-1 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 16,647,240.00 Class 2C-CB-1 X Certificate Interest Rate: 5.500% applied to the Class C-X Notional Amount Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: August March 25, 2035 Class 2C-CB-1 X Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class C-X Notional Amount as of the Cut-Off Date: $16,647,240.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 2X 0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2D-CB-2 X Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 25-CB-1 A-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 36,000,000.00 Class 25-CB-1 A-6 Certificate Interest Rate: 5.500% Variable, applied to the Class 5-A-6 Notional Amount Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 25-CB-1 A-6 Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class 5-A-6 Notional Amount as of the Cut-Off Date: $36,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6X 6 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26January 30, 20052006. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 3-A-10 Certificates will provide credit support to certain Classes of Certificates, as described in the Pooling Agreement. WMALT Series 20052006-7 1 Portion of the Class 23-CB-1 A-10 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 3,595,000.00 Class 23-CB-1 A-10 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August January 1, 2005 2006 First Distribution Date: September 26February 27, 2005 2006 Last Scheduled Distribution Date: August February 25, 2035 2036 Class 23-CB-1 A-10 Principal Balance as of the Cut-Off Date: $24,424,200.00 3,595,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 KY 7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 24-CB-2 CB Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.by

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26July 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 6 Portion of the Class 2-CB-1 A-8 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 29,000,000.00 Class 2-CB-1 A-8 Certificate Interest Rate: 5.500% Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 A-8 Principal Balance as of the Cut-Off Date: $24,424,200.00 29,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 92922F Y9 3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26March 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 2 Portion of the Class 23-CB-1 A Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 26,468,300.00 Class 23-CB-1 A Certificate Interest Rate: 5.500% Cut-Off Date: August March 1, 2005 First Distribution Date: September 26April 25, 2005 Last Scheduled Distribution Date: August April 25, 2035 2020 Class 23-CB-1 A Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 26,468,300.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 3W 1 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 X Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 24-CB-1 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 28,498,000.00 Class 24-CB-1 A-1 Certificate Interest Rate: 5.500% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 2020 Class 24-CB-1 A-1 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 28,498,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6Q 1 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 2-CB-1 Principal Balance CB-10 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 30,000,000.00 Class 2-CB-1 CB-10 Certificate Interest Rate: 5.500% Variable, applied to the Class CB-10 Notional Amount Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 2-CB-1 CB-10 Principal Balance as of the Cut-Off off Date: $24,424,200.00 0.00 Class CB-10 Notional Amount as of the Cut-off Date: $30,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6F 5 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-11 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August April 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 1-CB-6 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 3 Portion of the Class 21-CB-1 CB-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 8,770,300.00 Class 21-CB-1 CB-6 Certificate Interest Rate: 5.500% Cut-Off Date: August April 1, 2005 First Distribution Date: September 26May 25, 2005 Last Scheduled Distribution Date: August May 25, 2035 Class 21-CB-1 CB-6 Principal Balance as of the Cut-Off Date: $24,424,200.00 8,770,300.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 5E 9 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26November 29, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 10 Portion of the Class 2C-CB-1 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 19,167,004.00 Class 2C-CB-1 X Certificate Interest Rate: 5.500% 6.000%, applied to the Class C-X Notional Amount Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: August December 25, 2035 Class 2C-CB-1 X Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class C-X Notional Amount as of the Cut-Off Date: $19,167,004.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 GT3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 P Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 2-CB-1 CB Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 28,570,000.00 Class 2-CB-1 CB Certificate Interest Rate: 5.5005.000% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 2020 Class 2-CB-1 CB Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 28,570,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6N 8 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 23-CB-2 CB Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 A-7 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 72,000,000.00 Class 2-CB-1 A-7 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-7 Principal Balance as of the Cut-Off Date: $24,424,200.00 72,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 JC7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 A-8 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26March 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 2 Portion of the Class 2C-CB-1 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 29,838,417.72 Class 2C-CB-1 X Certificate Interest Rate: 5.500% applied to the Class C-X Notional Amount Cut-Off Date: August March 1, 2005 First Distribution Date: September 26April 25, 2005 Last Scheduled Distribution Date: August April 25, 2035 Class 2C-CB-1 X Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class C-X Notional Amount as of the Cut-Off Date: $29,838,417.72 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 3X 9 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 P Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 123,295,000.00 Class 2-CB-1 A-2 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 123,295,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 HX3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 A-3 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26February 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 1 Portion of the Class 26-CB-1 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 17,677,300.00 Class 26-CB-1 A-1 Certificate Interest Rate: 5.5006.500% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: August March 25, 2035 Class 26-CB-1 A-1 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 17,677,300.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 2R 3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26March 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 2 Portion of the Class 2-CB-1 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 5,795,000.00 Class 2-CB-1 A-1 Certificate Interest Rate: 5.500% Cut-Off Date: August March 1, 2005 First Distribution Date: September 26April 25, 2005 Last Scheduled Distribution Date: August April 25, 2035 Class 2-CB-1 A-1 Principal Balance as of the Cut-Off Date: $24,424,200.00 5,795,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 3Q 4 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 A-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26February 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 1 Portion of the Class 23-CB-1 A Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 21,221,500.00 Class 23-CB-1 A Certificate Interest Rate: 5.5005.000% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: August March 25, 2035 2020 Class 23-CB-1 A Principal Balance as of the Cut-Off Date: $24,424,200.00 21,221,500.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 2M 4 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 24-CB-2 A Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26January 30, 20052006. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 1-A-2 Certificates will provide credit support to certain Classes of Certificates, as described in the Pooling Agreement. WMALT Series 20052006-7 1 Portion of the Class 21-CB-1 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 700,000.00 Class 21-CB-1 A-2 Certificate Interest Rate: 5.5005.550% Cut-Off Date: August January 1, 2005 2006 First Distribution Date: September 26February 27, 2005 2006 Last Scheduled Distribution Date: August February 25, 2035 2036 Class 21-CB-1 A-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 700,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 KK 7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-1 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 25-CB-1 A-8 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 5,841,000.00 Class 25-CB-1 A-8 Certificate Interest Rate: 5.500% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 25-CB-1 A-8 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 5,841,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6Z 1 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26March 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 2 Portion of the Class 21-CB-1 A-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 10,700,000.00 Class 21-CB-1 A-6 Certificate Interest Rate: 5.500% Cut-Off Date: August March 1, 2005 First Distribution Date: September 26April 25, 2005 Last Scheduled Distribution Date: August April 25, 2035 Class 21-CB-1 A-6 Principal Balance as of the Cut-Off Date: $24,424,200.00 10,700,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 3P 6 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 123,295,000.00 Class 2-CB-1 A-2 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 123,295,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 HX3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 Principal Balance A-6 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 30,000,000.00 Class 2-CB-1 A-6 Certificate Interest Rate: 5.500% Variable, applied to the Class A-6 Notional Amount Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-6 Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class A-6 Notional Amount as of the Cut-Off Date: $30,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 JB9 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26November 29, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 4-CB-2 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 10 Portion of the Class 24-CB-1 CB-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 1,000,000.00 Class 24-CB-1 CB-2 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: August December 25, 2035 Class 24-CB-1 CB-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 1,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 GN6 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 24-CB-2 CB-3 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26January 29, 20052007. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 20052007-7 1 Portion of the Class 2C-CB-1 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 1,618,726.00 Class 2C-CB-1 X Certificate Interest Rate: 5.500% 6.500%, applied to the Class C-X Notional Amount Cut-Off Date: August January 1, 2005 2007 First Distribution Date: September February 26, 2005 2007 Last Scheduled Distribution Date: August February 25, 2035 2037 Class 2C-CB-1 X Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class C-X Notional Amount as of the Cut-Off Date: $1,618,726.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 00000XXX0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 P Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another trust that owns a pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26January 30, 20052006. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 5-CB-6 Certificates will provide credit support to certain Classes of Certificates, as described in the Pooling Agreement. WMALT Series 20052006-7 1 Portion of the Class 25-CB-1 CB-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 1,726,000.00 Class 25-CB-1 CB-6 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August January 1, 2005 2006 First Distribution Date: September 26February 27, 2005 2006 Last Scheduled Distribution Date: August February 25, 2035 2036 Class 25-CB-1 CB-6 Principal Balance as of the Cut-Off Date: $24,424,200.00 1,726,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 LF 7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 X Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 2-CB-1 Principal Balance CB-16 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 53,545.00 Class 2-CB-1 CB-16 Certificate Interest Rate: 5.5005.50% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 2-CB-1 CB-16 Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class CB-16 Notional Amount as of the Cut-Off Date: $53,545.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6M 0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26January 29, 20052007. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 20052007-7 1 Portion of the Class 21-CB-1 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 9,501,300.00 Class 21-CB-1 A-1 Certificate Interest Rate: 5.5006.000% Cut-Off Date: August January 1, 2005 2007 First Distribution Date: September February 26, 2005 2007 Last Scheduled Distribution Date: August February 25, 2035 2037 Class 21-CB-1 A-1 Principal Balance as of the Cut-Off Date: $24,424,200.00 9,501,300.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 00000XXX0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another trust that owns a pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 2-CB-1 CB-11 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 32,615,000.00 Class 2-CB-1 CB-11 Certificate Interest Rate: 5.500% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 2-CB-1 CB-11 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 32,615,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6G 3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 CB-12 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 25-CB-1 A-7 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 108,199,000.00 Class 25-CB-1 A-7 Certificate Interest Rate: 5.500% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 Class 25-CB-1 A-7 Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 108,199,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6Y 4 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 30,000,000.00 Class 2-CB-1 A-5 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-5 Principal Balance as of the Cut-Off Date: $24,424,200.00 30,000,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 JA1 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August April 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT The Class 1-CB-2 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. Series 2005-7 3 Portion of the Class 21-CB-1 CB-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 2,049,000.00 Class 21-CB-1 CB-2 Certificate Interest Rate: 5.500% Cut-Off Date: August April 1, 2005 First Distribution Date: September 26May 25, 2005 Last Scheduled Distribution Date: August May 25, 2035 Class 21-CB-1 CB-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 2,049,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 5A 7 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 21-CB-2 CB-3 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August April 26, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 3 Portion of the Class 2-CB-1 Principal Balance A-4 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 46,317,000.00 Class 2-CB-1 A-4 Certificate Interest Rate: 5.500% Variable, applied to the Class 2-A-4 Notional Amount Cut-Off Date: August April 1, 2005 First Distribution Date: September 26May 25, 2005 Last Scheduled Distribution Date: August May 25, 2035 Class 2-CB-1 A-4 Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class 2-A-4 Notional Amount as of the Cut-Off Date: $46,317,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 5J 8 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26October 27, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 9 Portion of the Class 2C-CB-1 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 22,925,400.00 Class 2C-CB-1 X Certificate Interest Rate: 5.500% %, applied to the Class C-X Notional Amount Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: August November 25, 2035 Class 2C-CB-1 X Principal Balance as of the Cut-Off Date: $24,424,200.00 0.00 Class C-X Notional Amount as of the Cut-Off Date: $22,925,400.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 FP2 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2C-CB-2 P Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26January 30, 20052006. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 5-CB-5 Certificates will provide credit support to certain Classes of Certificates, as described in the Pooling Agreement. WMALT Series 20052006-7 1 Portion of the Class 25-CB-1 CB-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 14,383,600.00 Class 25-CB-1 CB-5 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August January 1, 2005 2006 First Distribution Date: September 26February 27, 2005 2006 Last Scheduled Distribution Date: August February 25, 2035 2036 Class 25-CB-1 CB-5 Principal Balance as of the Cut-Off Date: $24,424,200.00 14,383,600.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 LE 0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 25-CB-2 CB-6 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26July 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 6 Portion of the Class 2-CB-1 A-9 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 3,925,100.00 Class 2-CB-1 A-9 Certificate Interest Rate: 5.500% Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: August 25, 2035 Class 2-CB-1 A-9 Principal Balance as of the Cut-Off Date: $24,424,200.00 3,925,100.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 92922F Z5 0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 A-8 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 15,000,700.00 Class 2-CB-1 A-8 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-8 Principal Balance as of the Cut-Off Date: $24,424,200.00 15,000,700.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 JD5 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 A-9 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26May 25, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 4 Portion of the Class 23-CB-1 CB Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 43,691,000.00 Class 23-CB-1 CB Certificate Interest Rate: 5.500% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: August June 25, 2035 2020 Class 23-CB-1 CB Principal Balance as of the Cut-Off DateBalance: $24,424,200.00 43,691,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 939336 6P 3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class A-9 Certificates will provide credit support to certain Classes of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 A-9 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 7,330,000.00 Class 2-CB-1 A-9 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 A-9 Principal Balance as of the Cut-Off Date: $24,424,200.00 7,330,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 JE3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 X Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26January 29, 20052007. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 20052007-7 1 Portion of the Class 21-CB-1 A-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 44,977,500.00 Class 21-CB-1 A-3 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August January 1, 2005 2007 First Distribution Date: September February 26, 2005 2007 Last Scheduled Distribution Date: August February 25, 2035 2037 Class 21-CB-1 A-3 Principal Balance as of the Cut-Off Date: $24,424,200.00 44,977,500.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 00000XXX0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another trust that owns a pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26December 28, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. WMALT Series 2005-7 11 Portion of the Class 2-CB-1 P Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 1,752,850.00 Class 2-CB-1 P Certificate Interest Rate: 5.5000.00% Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: August January 25, 2035 2036 Class 2-CB-1 P Principal Balance as of the Cut-Off Date: $24,424,200.00 1,752,850.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 JG8 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 B-1 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES WaMu ASSET ACCEPTANCE CORP.

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26January 29, 20052007. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 2-A-2 Certificates will provide credit support to certain Classes of Certificates, as described in the Pooling Agreement. WMALT Series 20052007-7 1 Portion of the Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 1,474,000.00 Class 2-CB-1 A-2 Certificate Interest Rate: 5.5006.000% Cut-Off Date: August January 1, 2005 2007 First Distribution Date: September February 26, 2005 2007 Last Scheduled Distribution Date: August January 25, 2035 2022 Class 2-CB-1 A-2 Principal Balance as of the Cut-Off Date: $24,424,200.00 1,474,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 00000XXX0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 2-CB-2 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another trust that owns a pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WaMu ASSET ACCEPTANCE CORP. This Certificate is issued by Washington Mutual Mortgage Pass-Through Certificates WMALT Series 2007-1 Trust. This Certificate represents ownership of one or more “regular interests” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is January 29, 2007. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. This Certificate is a Subsequent Exchangeable Certificate, as described in the Pooling Agreement. WMALT Series 2007-1 Portion of the Class 2-A-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $0.00 Class 2-A-3 Certificate Interest Rate: 5.500% Cut-Off Date: January 1, 2007 First Distribution Date: February 26, 2007 Last Scheduled Distribution Date: January 25, 2022 Class 2-A-3 Principal Balance as of the Cut-Off Date: $0.00 Maximum Initial Class 2-A-3 Principal Balance: $30,225,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 00000XXX0 WASHINGTON MUTUAL MORTGAGE SECURITIES PASS-THROUGH CERTIFICATE Evidencing a beneficial interest in a trust that owns a pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WaMu ASSET ACCEPTANCE CORP.. This Certificate is issued by Washington Mutual Mortgage Pass-Through Certificates WMALT Series 2007-1 Trust. This Certificate represents ownership of one or more “regular interests” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is January 29, 2007. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. This Certificate is a Subsequent Exchangeable Certificate, as described in the Pooling Agreement. WMALT Series 2007-1 Portion of the Class 2-A-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $0.00 Class 2-A-4 Certificate Interest Rate: 5.750% Cut-Off Date: January 1, 2007 First Distribution Date: February 26, 2007 Last Scheduled Distribution Date: January 25, 2022 Class 2-A-4 Principal Balance as of the Cut-Off Date: $0.00 Maximum Initial Class 2-A-4 Principal Balance: $30,225,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 00000XXX0 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Evidencing a beneficial interest in a trust that owns a pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WaMu ASSET ACCEPTANCE CORP. This Certificate is issued by Washington Mutual Mortgage Pass-Through Certificates WMALT Series 2007-1 Trust. This Certificate represents ownership of one or more “regular interests” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is January 29, 2007. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Trust or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. This Certificate is a Subsequent Exchangeable Certificate, as described in the Pooling Agreement. WMALT Series 2007-1 Portion of the Class 2-A-5 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $0.00

Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of 1986, as amended. The issue date of this Certificate is August 26October 27, 2005. Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein. The Class 4-A-5 Certificates will provide credit support to other Classes of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 24-CB-1 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $24,424,200.00 1,052,000.00 Class 24-CB-1 A-5 Certificate Interest Rate: 5.500% Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: August November 25, 2035 Class 24-CB-1 A-5 Principal Balance as of the Cut-Off Date: $24,424,200.00 1,052,000.00 Cede & Co. Registered Owner Exhibit A CUSIP 93934F BM3 FB3 WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE Class 25-CB-2 A-1 Evidencing a beneficial interest in a pool of assets consisting of beneficial interests in another pool of assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans formed by WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.