Upcoming Change in Postmark Regulations

USPS Making Changes to Postmark Date System:

The U.S. Postal Service (USPS) is changing its postmark date system, effective 12/24/25. This new rule, published in the 11/24/25 Federal Register, clarifies that a machine-applied postmark indicates the date of the “first automated processing operation” at a processing facility, which may be later than the date the mail was dropped off. This could be problematic for tax filings, because if received after the due date, the document won’t be considered timely filed or the payment timely made unless the postmark bears a date on or before the due date (IRC Sec. 7502). According to the rule, a sender who relies on this timely mailing rule should request a manual postmark by presenting their envelope at a USPS retail counter. The postage validation imprint applied to the envelope when a customer pays for postage will also show the correct USPS acceptance date. Senders may also use Registered or Certified Mail to obtain a receipt as evidence of the mailing date. FR Doc. 2025-20740.

Information provided by PPC Five-Minute Tax Briefing, December 23, 2025, No. 2025-24