Effective December 24, 2025, the post office will change the way they postmark mail. Instead of the postmark being dated the day the mail is delivered to the local post office, the postmark will now reflect the date the mail is first sorted at a regional facility.
Old Method: The postmark was the date the mail was dropped off at the local post office, a blue postal box, or your mailbox.
New Method: The postmark will not be applied until the mail piece arrives and is sorted at a regional facility. Possibly one or more days after mailing.
What does this matter? For tax filings, the postmark date is considered to be the date a return is filed or payment is made. If a return or payment is due the 15th of the month and it is delivered to the post office on that date, it may not be postmarked until a later date. If that is the case, the filing would be considered late and interest and penalties may apply.
What to do:
- Hand deliver the return or payment to your local post office's counter and ask that the postmark be applied manually.
- Use certified mail and file the mailing receipt with your copy of the return or payment.
- Use an approved private delivery services. Click here for a list of IRS approved private delivery services.
- Avoid using your mailbox, a blue postal service box, or even in-post-office mail slots for mailing tax returns or payments.
- Our recommendation: Whenever possible, use electronic filing and payment options. Read more...
