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. 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 1-A-7 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 Class 1-A-7 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September 25, 2035 Class 1-A-7 Principal Balance as of the Cut-Off Date: $1,000,000.00 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

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. Interest is not payable with respect to this Certificate. 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 1C-A-7 P Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,897,569.00 Class 1C-A-7 P Certificate Interest Rate: 5.5000.00% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September 25, 2035 Class 1C-A-7 P Principal Balance as of the Cut-Off Date: $1,000,000.00 1,897,569.00 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

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 12-A-7 CB-2 Certificates will provide credit support to another Class other Classes of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 Portion of the Class 12-A-7 CB-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 4,195,000.00 Class 12-A-7 CB-2 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 12-A-7 CB-2 Principal Balance as of the Cut-Off Date: $1,000,000.00 4,195,000.00 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

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 12-A-7 CB-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 31,569,066.00 Class 12-A-7 CB-4 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 12-A-7 CB-4 Principal Balance as of the Cut-Off Date: $1,000,000.00 31,569,066.00 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

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 12-A-7 CB-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 31,022,740.00 Class 12-A-7 CB-5 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 12-A-7 CB-5 Principal Balance as of the Cut-Off Date: $1,000,000.00 31,022,740.00 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

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. 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 1-A-7 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 50,000,000.00 Class 1-A-7 A-2 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September 25, 2035 Class 1-A-7 A-2 Principal Balance as of the Cut-Off Date: $1,000,000.00 50,000,000.00 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

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 1-A-7 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 16,001,326.00 Class 1-A-7 A-5 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September 25, 2035 Class 1-A-7 A-5 Principal Balance as of the Cut-Off Date: $1,000,000.00 16,001,326.00 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

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 1-A-7 A-8 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 4,215,000.00 Class 1-A-7 A-8 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September 25, 2035 Class 1-A-7 A-8 Principal Balance as of the Cut-Off Date: $1,000,000.00 4,215,000.00 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

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 12-A-7 CB-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 41,289,416.00 Class 12-A-7 CB-6 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 12-A-7 CB-6 Principal Balance as of the Cut-Off Date: $1,000,000.00 41,289,416.00 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

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 12-A-7 CB-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 149,937,994.00 Class 12-A-7 CB-3 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 12-A-7 CB-3 Principal Balance as of the Cut-Off Date: $1,000,000.00 149,937,994.00 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

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 1-A-7 A-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 59,304,107.00 Class 1-A-7 A-4 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September 25, 2035 Class 1-A-7 A-4 Principal Balance as of the Cut-Off Date: $1,000,000.00 59,304,107.00 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

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 1-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 13,552,800.00 Class 1-A-7 A-1 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September 25, 2035 Class 1-A-7 A-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 13,552,800.00 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

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 1C-A-7 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 14,369,296.00 Class 1C-A-7 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: September 25, 2035 Class 1C-A-7 X Principal Balance as of the Cut-Off Date: $1,000,000.00 0.00 Class C-X Notional Amount as of the Cut-Off Date: $14,369,296.00 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

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 12-A-7 CB-7 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 3,753,584.00 Class 12-A-7 CB-7 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 12-A-7 CB-7 Principal Balance as of the Cut-Off Date: $1,000,000.00 3,753,584.00 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

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 12-A-7 CB-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 24,424,200.00 Class 12-A-7 CB-1 Certificate Interest Rate: 5.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 12-A-7 CB-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 24,424,200.00 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

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 13-A-7 CB Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 37,805,200.00 Class 13-A-7 CB Certificate Interest Rate: 5.5006.500% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 13-A-7 CB Principal Balance as of the Cut-Off Date: $1,000,000.00 37,805,200.00 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

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 14-A-7 CB Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 29,539,800.00 Class 14-A-7 CB Certificate Interest Rate: 5.5007.000% Cut-Off Date: August 1, 2005 First Distribution Date: September 26, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 14-A-7 CB Principal Balance as of the Cut-Off Date: $1,000,000.00 29,539,800.00 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

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 14-A-7 A-5 Certificates will provide credit support to another Class other Classes of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 14-A-7 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,052,000.00 Class 14-A-7 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: September November 25, 2035 Class 14-A-7 A-5 Principal Balance as of the Cut-Off Date: $1,000,000.00 1,052,000.00 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

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 15-A-7 CB-6 Certificates will provide credit support to another Class certain Classes of Certificates, as described in the Pooling Agreement. WMALT Series 20052006-7 1 Portion of the Class 15-A-7 CB-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,726,000.00 Class 15-A-7 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: September February 25, 2035 2036 Class 15-A-7 CB-6 Principal Balance as of the Cut-Off Date: $1,000,000.00 1,726,000.00 Registered Owner Exhibit A CUSIP 93934F LF 7 Class C-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

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. The Class 1-A-7 A-6 Certificates will provide credit support to another Class other Classes of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 1 Portion of the Class 1-A-7 A-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,550,000.00 Class 1-A-7 A-6 Certificate Interest Rate: 5.500% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: September March 25, 2035 Class 1-A-7 A-6 Principal Balance as of the Cut-Off Date: $1,000,000.00 1,550,000.00 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

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-7 A-2 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 1-A-7 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,638,000.00 Class 1-A-7 A-2 Certificate Interest Rate: 5.500% Cut-Off Date: August March 1, 2005 First Distribution Date: September 26April 25, 2005 Last Scheduled Distribution Date: September April 25, 2035 Class 1-A-7 A-2 Principal Balance as of the Cut-Off Date: $1,000,000.00 1,638,000.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 15-A-7 A-8 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 28,305,700.00 Class 15-A-7 A-8 Certificate Interest Rate: 5.500% Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 15-A-7 A-8 Principal Balance as of the Cut-Off Date: $1,000,000.00 28,305,700.00 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

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. 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 4 Portion of the Class 1-A-7 CB-9 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 30,000,000.00 Class 1-A-7 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: September June 25, 2035 Class 1-A-7 CB-9 Principal Balance as of the Cut-Off Date: $1,000,000.00 30,000,000.00 Registered Owner Exhibit A CUSIP 939336 6E 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 1-A-7 P Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,752,850.00 Class 1-A-7 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: September January 25, 2035 2036 Class 1-A-7 P Principal Balance as of the Cut-Off Date: $1,000,000.00 1,752,850.00 Exhibit A CUSIP 93934F JG8 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

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 1-A-7 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 12-A-7 Principal Balance A-4 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 73,950,000.00 Class 12-A-7 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: September November 25, 2035 Class 12-A-7 A-4 Principal Balance as of the Cut-Off Date: $1,000,000.00 0.00 Class 2-A-4 Notional Amount as of the Cut-Off Date: $73,950,000.00 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

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. 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 1 Portion of the Class 13-A-7 A Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 21,221,500.00 Class 13-A-7 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: September March 25, 2035 2020 Class 13-A-7 A Principal Balance as of the Cut-Off Date: $1,000,000.00 21,221,500.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 15-A-7 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 39,349,100.00 Class 15-A-7 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: September November 25, 2035 Class 15-A-7 A-5 Principal Balance as of the Cut-Off Date: $1,000,000.00 39,349,100.00 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

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 1-A-7 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 1C-A-7 Principal Balance X Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 19,167,004.00 Class 1C-A-7 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: September December 25, 2035 Class 1C-A-7 X Principal Balance as of the Cut-Off Date: $1,000,000.00 0.00 Class C-X Notional Amount as of the Cut-Off Date: $19,167,004.00 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

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. The Class 12-A-7 A-10 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 6 Portion of the Class 12-A-7 A-10 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 2,124,000.00 Class 12-A-7 A-10 Certificate Interest Rate: 5.500% Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 12-A-7 A-10 Principal Balance as of the Cut-Off Date: $1,000,000.00 2,124,000.00 Cede & Co. Registered Owner WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE 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

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 1-A-7 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 12-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 26,790,200.00 Class 12-A-7 A-1 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 12-A-7 A-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 26,790,200.00 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

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. The Class 15-A-7 A-2 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 1 Portion of the Class 15-A-7 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,760,500.00 Class 15-A-7 A-2 Certificate Interest Rate: 5.5006.000% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: September March 25, 2035 Class 15-A-7 A-2 Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 1,760,500.00 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

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 1-A-7 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 12-A-7 A-9 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 13,739,337.00 Class 12-A-7 A-9 Certificate Interest Rate: 5.5006.000% Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 12-A-7 A-9 Principal Balance as of the Cut-Off Date: $1,000,000.00 13,739,337.00 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

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. The Class 14-A-7 A-2 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 4 Portion of the Class 14-A-7 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,484,000.00 Class 14-A-7 A-2 Certificate Interest Rate: 5.500% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: September June 25, 2035 2020 Class 14-A-7 A-2 Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 1,484,000.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 1-A-7 A-8 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 15,000,700.00 Class 1-A-7 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: September January 25, 2035 2036 Class 1-A-7 A-8 Principal Balance as of the Cut-Off Date: $1,000,000.00 15,000,700.00 Registered Owner Exhibit A CUSIP 93934F JD5 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

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 13-A-7 A-10 Certificates will provide credit support to another Class certain Classes of Certificates, as described in the Pooling Agreement. WMALT Series 20052006-7 1 Portion of the Class 13-A-7 A-10 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 3,595,000.00 Class 13-A-7 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: September February 25, 2035 2036 Class 13-A-7 A-10 Principal Balance as of the Cut-Off Date: $1,000,000.00 3,595,000.00 Registered Owner Exhibit A CUSIP 93934F KY 7 Class 4-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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 13-A-7 CB Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 21,143,300.00 Class 13-A-7 CB Certificate Interest Rate: 5.500% Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: September October 25, 2035 2020 Class 13-A-7 CB Principal Balance as of the Cut-Off Date: $1,000,000.00 21,143,300.00 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

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. The Class 15-A-7 A-10 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 4 Portion of the Class 15-A-7 A-10 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 445,000.00 Class 15-A-7 A-10 Certificate Interest Rate: 5.500% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: September June 25, 2035 Class 15-A-7 A-10 Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 445,000.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 12-A-7 A-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 36,050,000.00 Class 12-A-7 A-4 Certificate Interest Rate: 5.500% Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 12-A-7 A-4 Principal Balance as of the Cut-Off Date: $1,000,000.00 36,050,000.00 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

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 1-A-7 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 14-A-7 CB-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 12,763,000.00 Class 14-A-7 CB-1 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: September December 25, 2035 Class 14-A-7 CB-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 12,763,000.00 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

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. 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 6 Portion of the Class 12-A-7 A-9 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 3,925,100.00 Class 12-A-7 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: September August 25, 2035 Class 12-A-7 A-9 Principal Balance as of the Cut-Off Date: $1,000,000.00 3,925,100.00 Cede & Co. Registered Owner WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE 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

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-A-7 CB-2 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 1-A-7 CB-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 2,049,000.00 Class 1-A-7 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: September May 25, 2035 Class 1-A-7 CB-2 Principal Balance as of the Cut-Off Date: $1,000,000.00 2,049,000.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 15-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 13,211,400.00 Class 15-A-7 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: September November 25, 2035 Class 15-A-7 A-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 13,211,400.00 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

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. 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 4 Portion of the Class 12-A-7 CB Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 28,570,000.00 Class 12-A-7 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: September June 25, 2035 2020 Class 12-A-7 CB Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 28,570,000.00 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

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-A-7 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 12-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 8,815,000.00 Class 12-A-7 A-1 Certificate Interest Rate: 5.500% Cut-Off Date: August April 1, 2005 First Distribution Date: September 26May 25, 2005 Last Scheduled Distribution Date: September May 25, 2035 Class 12-A-7 A-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 8,815,000.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 1-A-7 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 72,000,000.00 Class 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: September January 25, 2035 2036 Class 1-A-7 Principal Balance as of the Cut-Off Date: $1,000,000.00 72,000,000.00 Registered Owner Exhibit A CUSIP 93934F JC7 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

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 12-A-7 A-6 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 12-A-7 A-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 305,000.00 Class 12-A-7 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: September April 25, 2035 Class 12-A-7 A-6 Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 305,000.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 14-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 11,448,000.00 Class 14-A-7 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: September November 25, 2035 Class 14-A-7 A-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 11,448,000.00 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

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. 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 6 Portion of the Class 12-A-7 Principal Balance A-6 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 39,531,000.00 Class 12-A-7 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: September August 25, 2035 Class 12-A-7 A-6 Principal Balance as of the Cut-Off Date: $1,000,000.00 0.00 Class 2-A-6 Notional Amount as of the Cut-Off Date: $39,531,000.00 Cede & Co. Registered Owner WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 1-A-7 A-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 53,263,000.00 Class 1-A-7 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: September January 25, 2035 2036 Class 1-A-7 A-3 Principal Balance as of the Cut-Off Date: $1,000,000.00 53,263,000.00 Registered Owner Exhibit A CUSIP 93934F HY1 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

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. The Class 15-A-7 A-9 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 4 Portion of the Class 15-A-7 A-9 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 960,000.00 Class 15-A-7 A-9 Certificate Interest Rate: 5.500% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: September June 25, 2035 Class 15-A-7 A-9 Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 960,000.00 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

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-7 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 1-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 31,122,000.00 Class 1-A-7 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: September April 25, 2035 Class 1-A-7 A-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 31,122,000.00 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

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 12-A-7 A-4 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 12-A-7 A-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 2,650,000.00 Class 12-A-7 A-4 Certificate Interest Rate: 5.500% Cut-Off Date: August March 1, 2005 First Distribution Date: September 26April 25, 2005 Last Scheduled Distribution Date: September April 25, 2035 Class 12-A-7 A-4 Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 2,650,000.00 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

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. 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 1 Portion of the Class 16-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 17,677,300.00 Class 16-A-7 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: September March 25, 2035 Class 16-A-7 A-1 Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 17,677,300.00 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

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-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 20052006-7 1 Portion of the Class 12-A-7 CB-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 13,000,000.00 Class 12-A-7 CB-2 Certificate Interest Rate: 5.5007.000% Cut-Off Date: August January 1, 2005 2006 First Distribution Date: September 26February 27, 2005 2006 Last Scheduled Distribution Date: September February 25, 2035 2036 Class 12-A-7 CB-2 Principal Balance as of the Cut-Off Date: $1,000,000.00 13,000,000.00 Registered Owner Exhibit A CUSIP 93934F KM 3 Class 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 1-A-7 A-8 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 15,000,700.00 Class 1-A-7 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: September January 25, 2035 2036 Class 1-A-7 A-8 Principal Balance as of the Cut-Off Date: $1,000,000.00 15,000,700.00 Registered Owner Exhibit A CUSIP 93934F JD5 Class 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 1-A-7 Principal Balance A-4 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 53,263,000.00 Class 1-A-7 A-4 Certificate Interest Rate: 5.500% Variable, applied to the Class A-4 Notional Amount Cut-Off Date: August December 1, 2005 First Distribution Date: September 26January 25, 2005 2006 Last Scheduled Distribution Date: September January 25, 2035 2036 Class 1-A-7 A-4 Principal Balance as of the Cut-Off Date: $1,000,000.00 0.00 Class A-4 Notional Amount as of the Cut-Off Date: $53,263,000.00 Exhibit A CUSIP 93934F HZ8 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

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. 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 4 Portion of the Class 1-A-7 CB-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 500,000.00 Class 1-A-7 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: September June 25, 2035 Class 1-A-7 CB-6 Principal Balance as of the Cut-Off Date: $1,000,000.00 500,000.00 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

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. 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 6 Portion of the Class 12-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 44,055,000.00 Class 12-A-7 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: September August 25, 2035 Class 12-A-7 A-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 44,055,000.00 Cede & Co. Registered Owner WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 1-A-7 P Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,752,850.00 Class 1-A-7 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: September January 25, 2035 2036 Class 1-A-7 P Principal Balance as of the Cut-Off Date: $1,000,000.00 1,752,850.00 Exhibit A CUSIP 93934F JG8 Class 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

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-7 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 1-A-7 A-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 10,700,000.00 Class 1-A-7 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: September April 25, 2035 Class 1-A-7 A-6 Principal Balance as of the Cut-Off Date: $1,000,000.00 10,700,000.00 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

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-7 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 1-A-7 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 14,790,000.00 Class 1-A-7 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: September April 25, 2035 Class 1-A-7 A-5 Principal Balance as of the Cut-Off Date: $1,000,000.00 14,790,000.00 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

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 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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 12-A-7 A-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 24,612,300.00 Class 12-A-7 A-3 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 12-A-7 A-3 Principal Balance as of the Cut-Off Date: $1,000,000.00 24,612,300.00 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

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-7 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 13-A-7 A Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 26,468,300.00 Class 13-A-7 A Certificate Interest Rate: 5.500% Cut-Off Date: August March 1, 2005 First Distribution Date: September 26April 25, 2005 Last Scheduled Distribution Date: September April 25, 2035 2020 Class 13-A-7 A Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 26,468,300.00 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

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 1-A-7 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 12-A-7 A-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 35,454,950.00 Class 12-A-7 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: September November 25, 2035 Class 12-A-7 A-6 Principal Balance as of the Cut-Off Date: $1,000,000.00 35,454,950.00 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

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. The Class 16-A-7 A-2 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 1 Portion of the Class 16-A-7 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 530,400.00 Class 16-A-7 A-2 Certificate Interest Rate: 5.5006.500% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: September March 25, 2035 Class 16-A-7 A-2 Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 530,400.00 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

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 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-A-7 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 1-A-7 CB-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 356,447,000.00 Class 1-A-7 CB-3 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August April 1, 2005 First Distribution Date: September 26May 25, 2005 Last Scheduled Distribution Date: September May 25, 2035 Class 1-A-7 CB-3 Principal Balance as of the Cut-Off Date: $1,000,000.00 356,447,000.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 1-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 25,288,000.00 Class 1-A-7 A-1 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: September January 25, 2035 2036 Class 1-A-7 A-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 25,288,000.00 Registered Owner Exhibit A CUSIP 93934F HW5 Class 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 12-A-7 Principal Balance A-6 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 24,612,300.00 Class 12-A-7 A-6 Certificate Interest Rate: 5.500% Variable, applied to the Class 2-A-6 Notional Amount Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 12-A-7 A-6 Principal Balance as of the Cut-Off Date: $1,000,000.00 0.00 Class 2-A-6 Notional Amount as of the Cut-Off Date: $24,612,300.00 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

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. 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 6 Portion of the Class 12-A-7 A-8 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 29,000,000.00 Class 12-A-7 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: September August 25, 2035 Class 12-A-7 A-8 Principal Balance as of the Cut-Off Date: $1,000,000.00 29,000,000.00 Cede & Co. Registered Owner WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE 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

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. 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 4 Portion of the Class 1-A-7 Principal Balance CB-2 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 305,066,700.00 Class 1-A-7 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: September June 25, 2035 Class 1-A-7 CB-2 Principal Balance as of the Cut-Off Date: $1,000,000.00 0.00 Class CB-2 Notional Amount as of the Cut-Off Date: $305,066,700.00 Registered Owner Exhibit A CUSIP 939336 5X 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

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 13-A-7 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 13-A-7 CB-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 4,668,600.00 Class 13-A-7 CB-2 Certificate Interest Rate: 5.5006.000% Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 13-A-7 CB-2 Principal Balance as of the Cut-Off Date: $1,000,000.00 4,668,600.00 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

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. Interest is not payable with respect to this Certificate. 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 9 Portion of the Class 1C-A-7 P Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,128,110.00 Class 1C-A-7 P Certificate Interest Rate: 5.5000.00% Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 1C-A-7 P Principal Balance as of the Cut-Off Date: $1,000,000.00 1,128,110.00 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

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 1-A-7 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 14-A-7 Principal Balance CB-4 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 117,923,200.00 Class 14-A-7 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: September December 25, 2035 Class 14-A-7 CB-4 Principal Balance as of the Cut-Off Date: $1,000,000.00 0.00 Class 4-CB-4 Notional Amount as of the Cut-Off Date: $117,923,200.00 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

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. 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 1 Portion of the Class 17-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 45,530,700.00 Class 17-A-7 A-1 Certificate Interest Rate: 5.500% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: September March 25, 2035 Class 17-A-7 A-1 Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 45,530,700.00 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

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. 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 4 Portion of the Class 1-A-7 Principal Balance CB-16 Notional Amount as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 53,545.00 Class 1-A-7 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: September June 25, 2035 Class 1-A-7 CB-16 Principal Balance as of the Cut-Off Date: $1,000,000.00 0.00 Class CB-16 Notional Amount as of the Cut-Off Date: $53,545.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 15-A-7 A-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 26,673,768.00 Class 15-A-7 A-3 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 15-A-7 A-3 Principal Balance as of the Cut-Off Date: $1,000,000.00 26,673,768.00 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

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. 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 6 Portion of the Class 12-A-7 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 43,197,000.00 Class 12-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: September August 25, 2035 Class 12-A-7 Principal Balance as of the Cut-Off Date: $1,000,000.00 43,197,000.00 Cede & Co. Registered Owner WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE 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

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-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 20052006-7 1 Portion of the Class 1C-A-7 P Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 4,420,231.00 Class 1C-A-7 P Certificate Interest Rate: 5.5000.00% Cut-Off Date: August January 1, 2005 2006 First Distribution Date: September 26February 27, 2005 2006 Last Scheduled Distribution Date: September February 25, 2035 2036 Class 1C-A-7 P Principal Balance as of the Cut-Off Date: $1,000,000.00 4,420,231.00 Exhibit A CUSIP 93934F LH 3 Class 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 15-A-7 A-9 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 4,937,000.00 Class 15-A-7 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: September November 25, 2035 Class 15-A-7 A-9 Principal Balance as of the Cut-Off Date: $1,000,000.00 4,937,000.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 1-A-7 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 30,000,000.00 Class 1-A-7 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: September January 25, 2035 2036 Class 1-A-7 A-5 Principal Balance as of the Cut-Off Date: $1,000,000.00 30,000,000.00 Exhibit A CUSIP 93934F JA1 Class 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

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. Interest is not payable with respect to this Certificate. 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 6 Portion of the Class 1C-A-7 Principal PPrincipal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 349,561.00 Class 1C-A-7 Certificate PCertificate Interest Rate: 5.5000.00% Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 1C-A-7 Principal PPrincipal Balance as of the Cut-Off Date: $1,000,000.00 349,561.00 Cede & Co. Registered Owner WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE 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

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. 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 1 Portion of the Class 1-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 149,000,000.00 Class 1-A-7 A-1 Certificate Interest Rate: 5.500% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: September March 25, 2035 Class 1-A-7 A-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 149,000,000.00 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

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 1-A-7 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 1-A-7 CB Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 62,532,200.00 Class 1-A-7 CB Certificate Interest Rate: 5.5006.500% Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 1-A-7 CB Principal Balance as of the Cut-Off Date: $1,000,000.00 62,532,200.00 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

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-A-7 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 1-A-7 CB-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 39,748,000.00 Class 1-A-7 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: September May 25, 2035 Class 1-A-7 CB-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 39,748,000.00 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

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 1-A-7 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 12-A-7 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 25,000,000.00 Class 12-A-7 Certificate Interest Rate: 5.5005.750% Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 12-A-7 Principal Balance as of the Cut-Off Date: $1,000,000.00 25,000,000.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 12-A-7 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 106,010,500.00 Class 12-A-7 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: September November 25, 2035 Class 12-A-7 A-2 Principal Balance as of the Cut-Off Date: $1,000,000.00 106,010,500.00 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

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. 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 6 Portion of the Class 12-A-7 A-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 4,252,334.00 Class 12-A-7 A-3 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 12-A-7 A-3 Principal Balance as of the Cut-Off Date: $1,000,000.00 4,252,334.00 Cede & Co. Registered Owner WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 12-A-7 A-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 22,300,000.00 Class 12-A-7 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: September November 25, 2035 Class 12-A-7 A-1 Principal Balance as of the Cut-Off Date: $1,000,000.00 22,300,000.00 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

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. Interest is not payable with respect to this Certificate. 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 2 Portion of the Class 13-A-7 P Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,225,835.00 Class 13-A-7 P Certificate Interest Rate: 5.5000.00% Cut-Off Date: August March 1, 2005 First Distribution Date: September 26April 25, 2005 Last Scheduled Distribution Date: September April 25, 2035 2020 Class 13-A-7 P Principal Balance as of the Cut-Off Date: $1,000,000.00 1,225,835.00 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

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. 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 1 Portion of the Class 1-A-7 A-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 29,036,000.00 Class 1-A-7 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: September March 25, 2035 Class 1-A-7 A-3 Principal Balance as of the Cut-Off Date: $1,000,000.00 29,036,000.00 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

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. 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 1 Portion of the Class 1-A-7 A-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 13,935,000.00 Class 1-A-7 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: September March 25, 2035 Class 1-A-7 A-4 Principal Balance as of the Cut-Off Date: $1,000,000.00 13,935,000.00 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

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. 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 1 Portion of the Class 14-A-7 A Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 25,283,300.00 Class 14-A-7 A Certificate Interest Rate: 5.500% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: September March 25, 2035 2020 Class 14-A-7 A Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 25,283,300.00 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

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. The Class 17-A-7 A-4 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 1 Portion of the Class 17-A-7 A-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 226,200.00 Class 17-A-7 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: September March 25, 2035 Class 17-A-7 A-4 Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 226,200.00 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

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. The Class 1-A-7 CB-12 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 4 Portion of the Class 1-A-7 CB-12 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 1,698,000.00 Class 1-A-7 CB-12 Certificate Interest Rate: 5.500% Cut-Off Date: August May 1, 2005 First Distribution Date: September 26June 27, 2005 Last Scheduled Distribution Date: September June 25, 2035 Class 1-A-7 CB-12 Principal Balance as of the Cut-Off DateBalance: $1,000,000.00 1,698,000.00 Registered Owner Exhibit A CUSIP 939336 6H 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

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 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 1-A-7 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 12-A-7 A-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 73,950,000.00 Class 12-A-7 A-3 Certificate Interest Rate: 5.500% Variable Cut-Off Date: August November 1, 2005 First Distribution Date: September 26December 27, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 12-A-7 A-3 Principal Balance as of the Cut-Off Date: $1,000,000.00 73,950,000.00 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

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. 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 1 Portion of the Class 12-A-7 A Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 65,117,000.00 Class 12-A-7 A Certificate Interest Rate: 5.5006.000% Cut-Off Date: August February 1, 2005 First Distribution Date: September 26March 25, 2005 Last Scheduled Distribution Date: September March 25, 2035 Class 12-A-7 A Principal Balance as of the Cut-Off Date: $1,000,000.00 65,117,000.00 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 11 Portion of the Class 1-A-7 A-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 30,000,000.00 Class 1-A-7 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: September January 25, 2035 2036 Class 1-A-7 A-5 Principal Balance as of the Cut-Off Date: $1,000,000.00 30,000,000.00 Exhibit A CUSIP 93934F JA1 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

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-A-7 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 12-A-7 A-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 34,500,000.00 Class 12-A-7 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: September May 25, 2035 Class 12-A-7 A-2 Principal Balance as of the Cut-Off Date: $1,000,000.00 34,500,000.00 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

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. 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 6 Portion of the Class 13-A-7 CB Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 96,253,000.00 Class 13-A-7 CB Certificate Interest Rate: 5.500% Cut-Off Date: August July 1, 2005 First Distribution Date: September 26August 25, 2005 Last Scheduled Distribution Date: September August 25, 2035 Class 13-A-7 CB Principal Balance as of the Cut-Off Date: $1,000,000.00 96,253,000.00 Cede & Co. Registered Owner WASHINGTON MUTUAL MORTGAGE PASS-THROUGH CERTIFICATE 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

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 1-A-7 Certificates will provide credit support to another Class of Certificates, as described in the Pooling Agreement. WMALT Series 2005-7 9 Portion of the Class 14-A-7 A-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate: $1,000,000.00 12,231,900.00 Class 14-A-7 A-4 Certificate Interest Rate: 5.500% Cut-Off Date: August October 1, 2005 First Distribution Date: September 26November 25, 2005 Last Scheduled Distribution Date: September November 25, 2035 Class 14-A-7 A-4 Principal Balance as of the Cut-Off Date: $1,000,000.00 12,231,900.00 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