39 CFR 501.17 - Decertified Postage Evidencing Systems.
(a) A Decertified Postage Evidencing System is a device for which the provider's authority to distribute has been withdrawn by the Postal Service as a result of any retirement plan for a given class of meters published by the Postal Service in the Federal Register; a suspension or revocation under § 501.6; or a voluntary withdrawal undertaken by the provider.
(c) To the extent postage meters are involved, the provider must utilize the approved procedures for lost and stolen meters under § 501.14(c)(7) to locate the meter and remove it from service by the agreed upon date.
(d) Decertified Postage Evidencing Systems that are not submitted to the Postal Service for refund within one hundred and eighty (180) days of the agreed upon withdrawal from service date will not be eligible for refund of unused postage.
(e) Postage indicia printed by Decertified Postage Evidencing Systems may no longer be considered valid postage one hundred and eighty (180) days from the agreed upon withdrawal from service date.