U.S. Postal Service Postmark Changes
Message from the Fairfield County Treasurer's Office regarding postmark dates by the U.S. Postal Service.
The U.S. Postal Service is making new changes in 2026, including adjustments to the postmark process, which could result in late fees and penalties for anyone mailing time-sensitive documents such as tax returns or bill payments.
For decades, the postmark – an official mark that shows where and when mail was accepted by the Postal Service – has been used in law as proof that an individual met a deadline, such as submitting a ballot by Election Day.
A USPS postmark used to indicate the date when mail was dropped in a mailbox or submitted at the post office counter. Now, USPS is clarifying in a new rule that the postmark will reflect the date an envelope is first processed by an automated USPS sorting machine, potentially days after it was dropped off – not the actual drop-off date. [Source: USA Today]