48 CFR §49.601-2

The following letter notice of termination is suggested for use if a contract for supplies is being terminated for convenience. With appropriate modifications, it may be used in terminating contracts for other than supplies and in terminating subcontracts. This notice shall be sent by certified mail, return receipt requested, or electronically, provided evidence of receipt is received by the contracting officer. If no prior electronic notice was issued, or if no confirmation of an electronic notice was received, use the alternate notice that follows this notice. Alternate notice. Substitute the following paragraph (a) for paragraph (a) of 49.601-2, Notice of Termination to Prime Contractors, if no prior electronic notice was issued, or if no confirmation of an electronic notice was received: