28 U.S.C. § 1743 - U.S. Code - Unannotated Title 28. Judiciary and Judicial Procedure § 1743. Demand on postmaster

The certificate of the Postmaster General or the Government Accountability Office of the mailing to a postmaster of a statement of his account and that payment of the balance stated has not been received shall be sufficient evidence of a demand notwithstanding any allowances or credits subsequently made. A copy of such statement shall be attached to the certificate.