(a) For redemption. To facilitate the redemption of called or maturing debentures, they may be presented and surrendered in the manner prescribed in this section in advance of the call or maturity date, as the case may be. Early presentation by holders will insure prompt payment of principal and interest when due. The debentures must first be assigned by the registered payee or his assignee, or by his duly constituted representative, if required, in the form and manner indicated in § 337.5, and must then be submitted to the Bureau of the Fiscal Service at the address given in § 337.14, accompanied by appropriate written advice. A transmittal advice for this purpose will accompany the notice of call.

(b) For purchase. Debentures, the purchase of which has been authorized prior to call or maturity, may be assigned as instructed in paragraph (a) of this section and immediately submitted in accordance with procedures prescribed by HUD for this purpose.