The United States Postal Service (USPS) has implemented a change to its postmarking procedures that could affect residents who rely on the mail for time-sensitive documents such as tax returns, absentee ballots, and bill payments.

For decades, Americans have operated under the assumption that if they drop an envelope in a blue collection box before the last pickup time on a specific date, it will be postmarked with that day’s date.

But the new regulation —formally outlined in the Federal Register as “Postmarks and Postal Possession”—clarifies that a machine-applied postmark now indicates the date the piece of mail was processed at a distribution center, not the date it was collected by the carrier or dropped at a local post office.

Because the USPS has been consolidating its network under the “Delivering for America” plan, local mail is often transported to regional processing centers hundreds of miles away before it receives its first scan.

This operational shift creates a “postmark lag.” A letter dropped in a mailbox in a rural town on April 15 might not reach the regional sorting facility until April 16 or 17.

• Old System: The postmark would often still reflect the collection date.
• New System: The postmark will simply read April 16 or 17—the moment the machine cancels the stamp.

For the IRS, courts, and billing departments, that mail is now late.

The change disproportionately affects:

1. Rural Residents: Mail from smaller towns often travels farther to reach a regional hub, increasing the likelihood of a date discrepancy.
2. Taxpayers: The “mailbox rule” (treating the postmark date as the filing date) is a critical protection for avoiding penalties.
3. Voters: In states where absentee ballots must be postmarked by Election Day, a ballot dropped in a box on Election Day might technically be postmarked the day after, potentially invalidating the vote.

The USPS has acknowledged this “operational reality” and provided a specific workaround for customers who need proof of mailing on a specific date. To ensure your mail is postmarked today, you cannot rely on your mailbox or the blue collection box.

You must physically go into the Post Office and request a “Manual Postmark.”

• Hand-Cancellation: You can ask the clerk at the counter to hand-stamp (cancel) your postage. This applies the date immediately. The new rule confirms this service is free of charge.
• Point-of-Sale Receipt: Purchasing postage at the counter (where they stick the label on for you) also generates a valid date record in the system.
• Certified/Registered Mail: For legal or tax documents, this remains the safest option, as the receipt serves as prima facie evidence of the mailing date.