Southern Africa Development Community Secretariat – Procurement and Grants Policy (6) A bid received by the Procuring Entity after the deadline for the submission of bids shall not be opened and shall be returned to the economic operator that submitted it. Similarly, pursuant to paragraph (5) (b) of this Article, unopened financial proposals shall be returned to the bidders who did not qualify following the technical evaluation. Article 36. Validity period; modification and withdrawal of bids (1) Bids shall be valid for the period of time specified in the bidding documents. (2) (a) (b) (3) Prior to the expiry of the validity period of the bids, the Procuring Entity may request bidders to extend it for an additional specified period of time. A bidder may refuse the request without forfeiting his bid security. In that case the validity period of his bid will terminate upon the expiry of the un-extended validity period. Bidders who agree to an extension of the validity period of their bids shall submit proof of the extension of the bid security or provide new bid securities to cover the extended validity. A bidder whose bid security is not extended, or has not provided a new bid security, is considered to have refused the request to extend the validity period of his bid. An economic operator may modify or withdraw his bid prior to the deadline for the submission of bids without forfeiting his bid security. The modification or notice of withdrawal is effective if it is received by the Procuring Entity prior to the deadline for the submission of bids. Article 37. Bid securities (1) When the Procuring Entity requires economic operators submitting bids, to provide a bid security: (a) The requirement shall apply to all such economic operators; (b) The bidding documents shall stipulate that the issuer of the bid security and the confirmer, if any, as well as the form and terms it, shall be acceptable to the Procuring Entity; (c) The Bidding documents may impose the obligation of providing Bid Securities by institutions legally established in the country of implementation of the contract or the country of the Contracting Authority; (d) Notwithstanding the provisions of subparagraph (b) of this paragraph, a bid security shall not be rejected by the Procuring Entity on the grounds that the bid security was not issued by an issuer accepted by the Procuring Entity unless such issuer was clearly identified in the bidding document as unacceptable issuer; (e) Prior to submitting a bid, an economic operator may request the Procuring Entity to confirm the acceptability of a proposed issuer of a bid security, or of a proposed confirmer. The Procuring Entity shall respond promptly to such a request; (f) Confirmation of the acceptability of a proposed issuer or of any proposed confirmer does not preclude the Procuring Entity from rejecting the bid security on the ground that the issuer or the confirmer, as the case may be, has become insolvent or otherwise lacks creditworthiness; (g) The Procuring Entity shall specify in the bidding documents all requirements with respect to the nature, format, amount and other principal terms and conditions of the required bid security; any requirement that refers directly or indirectly to the conduct of the shortlisted economic operator submitting the bid shall be limited to: 28