Effective December 24, 2025, the USPS postmark date will no longer be based on the date you drop off your mail. Instead, it will be based on the date the mail is first processed by USPS’s automated system.

As a result, tax returns or payments mailed on the deadline date may be considered late if the automated processing occurs after the due date.

What Is Changing?

Under the new rule, a machine-applied postmark will reflect:

- Not the date the mail is dropped into a mailbox, but

- The date the mail is first processed by an automated system at a USPS processing facility.

Example:
Even if you drop your tax return into a mailbox on April 15, if USPS begins automated processing on April 16, the postmark may show April 16, potentially resulting in a late filing or payment.

USPS-Recommended Methods to Avoid Late Filing Issues

To ensure timely filing and payment, USPS recommends the following options:

1. Manual Postmark

- Present your mail directly at a USPS retail counter and request a manual postmark showing the submission date.

2. Registered or Certified Mail

• Use Registered Mail or Certified Mail, which provides official proof of mailing and acceptance date.