The Mailbox Rule, Certificates of Mailing, etc., and USPS' New “Postmarks and Postal Possession” Rule

December 30, 2025

The USPS has clarified its “Postmarks and Postal Possession” rules to state that postmarks will no longer "necessarily indicate the first day that the Postal Service had possession of the mailpiece."  See Federal Register :: Postmarks and Postal Possession (https://www.federalregister.gov/documents/2025/11/24/2025-20740/postmarks-and-postal-possession#p-73), § 11.3.  Instead, the postmark will reflect either the "date of the first automated processing operation performed on a mailpiece or, alternately, the date when a mailpiece was accepted at a retail unit.”  Id.  They state that “[b]ecause most postmarks are applied at processing facilities, they do not necessarily represent either the place at which, or the date on which, the Postal Service first accepted possession of the mailpiece.  The date inscribed by a postmark applied at a processing facility may be later than the date that the mailpiece was first accepted by the Postal Service."  Id.

To ensure that mail is postmarked on the date it is placed in possession of the Postal Service, they advise customers to take the mail to the counter at a "Post Office, station, or branch" and "request, for no additional fee, a manual (local) postmark at any Post Office, station, or branch when tendering their mailpiece."  Id., § 11.4.

The rule states that postal practices have not changed and the rule simply clarifies Post Office practices; however, I believe that, for decades (if not longer), people believed that if they simply dropped off their mail at the Post Office during service hours, the postmark would reflect that date.  That is no longer the case.  The rule took effect on December 24, 2025.