Modification and Withdrawal of Bids 22.1 Bidders may modify or withdraw their bids by giving notice in writing before the deadline prescribed in Clause 20. 22.2 Each Bidder’s modification or withdrawal notice shall be prepared, sealed, marked, and delivered in accordance with Clause 18 & 19, with the outer and inner envelopes additionally marked “MODIFICATION” or “WITHDRAWAL”, as appropriate. 22.3 No bid may be modified after the deadline for submission of Bids. 22.4 Withdrawal or modification of a Bid between the deadline for submission of bids and the expiration of the original period of bid validity specified in Clause 15.1 above or as extended pursuant to Clause 15.2 may result in the forfeiture of the Bid security pursuant to Clause 16. 22.5 Bidders may offer discounts to, or modify the prices of their Bids only by submitting Bid modifications in accordance with this clause, or included in the original Bid submission.