With tax season deadlines looming, we would like to make sure you are aware that the United States Postal Service (USPS) has recently issued changes regarding postmarking mail. Effective December 24, 2025, the postmark date may no longer match the day the mail was dropped off or picked up at processing facilities but now reflects when it is scanned in at said facilities.

What is a Postmark?

Postmarked mail is a letter or package bearing an official USPS stamp that records the date an envelope is first processed at a regional sorting facility, not the date it was deposited by the mailer. This stamp serves as legal proof of the date the item entered into the mail system and is often used for deadlines such as taxes.

Changes to Postmarks

Now that the USPS has recently updated their rules, a 1–3-day delay may potentially occur, which can lead to missing deadlines and late fees for items such as taxes. Mail is now routed to a regional hub where the postmark is done.  Because postmarks reflect the date a mail piece is processed regionally rather than when it was deposited locally, traditional assumptions about “mail by the deadline” are no longer correct. Consequently, if returns are dropped at a local post office on or shortly before a tax filing deadline, they may not be postmarked until days later, potentially after the deadline. Furthermore, these changes affect scenarios beyond annual tax return obligations, including communications with regulatory authorities, quarterly payments, and Tax Court petitions, among others.

Ways to Get an Exact Mailing Date

For time sensitive items such as taxes during tax season, or sending paperwork to your CPA when you can’t drop it off or send it electronically, there are several ways one can obtain an exact mailing date.

• Requesting a Manual Postmark
  • Go to the clerk at the Post Office counter and ask for a manual postmark. The clerk will then stamp the envelope with that day’s date.
• Get a Certificate of Mailing
  • The official proof of mailing, USPS stamps a receipt showing the exact date they accepted the mail.
• Use Registered Mail
  • Offers great security through tracking and is handled under strict mailing policies. This is commonly used for valuable documents.

If you are mailing your CPA any paperwork pertaining to your taxes to adhere to a deadline, it must be sent much further in advance. We encourage you to use our technology to send your documentation electronically to prevent any delays.