New Postal Changes And How They May Affect You

Starting today. USPS updated how postmarks are defined and applied under its mailing standards. The key point is:

The postmark date no longer necessarily reflects the date you dropped a letter off. Instead, the postmark typically shows the date when USPS first processes the mail at a regional facility, not when it was handed in at your local post office or in a mailbox.

This means, a letter dropped off on a Friday evening might not reach the processing facility until Monday — so its postmark could show Monday’s date, not Friday’s. Likewise, mail sent right before a deadline may end up with a postmark that’s a day (or more) later than the date you actually mailed it. This can be especially important for deadlines tied to the postmark date.

Many laws and deadlines use the USPS postmark date as legal proof that something was mailed “on time.” This includes (but isn’t limited to):

Tax returns and payments — e.g., IRS and state tax deadlines. Charitable donation receipts for tax purposes. Election ballots or ballots mailed close to an election deadline. Legal filings, contracts, and other official documents. Property tax payments and other government remittances.

Under the new interpretation, if a deadline depends on the postmark and USPS stamps a later date because of processing delays, your letter could be treated as late even if you mailed it on or before the deadline.

How to Protect Yourself

If you need to prove something was mailed on a specific day, here are ways to ensure accurate proof:

1. Request a manual postmark at the retail counter

Bring your envelope inside and ask the clerk to hand-stamp it with the date you bring it in. This usually captures the date USPS accepted it.

2. Get a Postage Validation Imprint (PVI) or Certificate of Mailing

These provide official proof of the date you handed it to USPS, even if the automated postmark shows a later date.

3. Use mailing services with date proof

Registered Mail, Certified Mail, or other services include formal receipts or tracking dates.

4. Mail well before deadlines

Since automated processing can add a day or more, mailing earlier reduces the risk of a late postmark.

Some courts and laws (like state tax codes and the Internal Revenue Code) treat the postmark date strictly: if the stamped date is after a deadline, the item may not be considered timely — regardless of when you actually mailed it.

USPS has clarified that postmark dates may not match the day you mail something because mail is usually postmarked at regional processing centers. For time-sensitive mail relying on a postmark deadline, this can lead to late postmarks even if mailed on time. You can reduce risk by requesting manual postmarks or using services that provide dated receipts, and mailing early rather than close to the deadline. ++