31 CFR § 245.4 - Advice of nonreceipt or loss.

(a) In the event of the nonreceipt, loss or destruction of a check drawn on the United States Treasury, or the mutilation or defacement of such a check to an exent which renders it nonnegotiable, the claimant should immediately notify the agency that authorized the issuance of such check, describing the check, stating the purpose for which it was issued and giving, if possible, its date, amount, Treasury symbol and number.

(b) In cases involving mutiliated or defaced checks, the claimant should enclose the mutilated or defaced check with his communication to the agency.