48 C.F.R. § 752.7006
The following clause shall be used in all USAID contracts.
NOTICES (APR 1984)
Any notice given by any of the parties hereunder shall be sufficient only if in writing and delivered in person or sent by telegraph, cable, or registered or regular mail as follows:
To USAID: Administrator, U.S. Agency for International Development, Washington, DC 20523-0061. Attention: Contracting Officer (the name of the cognizant contracting officer with a copy to the appropriate Mission Director).
To Contractor: At Contractor's address shown on the cover page of this contract, or to such other address as either of such parties shall designate by notice given as herein required. Notices hereunder shall be effective when delivered in accordance with this clause or on the effective date of the notice, whichever is later.
(End of clause)
48 C.F.R. §752.7006