Important Update: USPS Postmarks and Proof of Mailing for Time-Sensitive Filings

The U.S. Postal Service (USPS) has issued a clarification to its postmark policy (Section 608.11), effective in late 2025, that affects how postmark dates are applied to mailed items. This clarification may impact time-sensitive filings that rely on a postmark to establish timely submission, including tax, legal, and election-related documents.

Under this clarification, machine postmarks will now reflect the date of first automated processing at a regional USPS facility, rather than the date an item is dropped off at a local post office. As a result, there may be a delay of one or more days between when an item is mailed and the postmark date applied by USPS.

Why this matters

• A postmark confirms USPS possession on the printed date, which may be later than the actual drop-off date
• Filings with deadlines that depend strictly on the postmark date could be considered late if mailed close to a deadline

How to protect your mailing date

• Request a hand-stamped postmark at the USPS counter
• Use Certified or Registered Mail, as the dated receipt serves as proof of mailing
• Purchase retail postage at the counter to obtain a dated acceptance label

This clarification does not change how mail is physically handled, and some mail may still not receive a postmark.

If you have questions or would like assistance evaluating how this may affect your filing or compliance procedures, please contact your Nisivoccia advisor.