A new USPS postmark rule took effect December 24, 2025. This rule applies to all mail, but in today’s post, I’ll focus on how it could impact your tax return, payments, or any other time-sensitive documents that you may need to mail to the IRS.
What was the old USPS postmark rule?
For decades, taxpayers have relied on the postmark date on their mail as proof of when they mailed their tax return, but how the USPS assigns that date is changing. Previously, the day you dropped your mail in a mailbox was the day that would be applied to your mail, so that was your postmark date.
What’s the new USPS postmark rule?
Now, the USPS won’t apply the postmark date to your mail until it is first processed at the regional facility. This means that the postmark date entered on the mail may be later than the day you mailed it or dropped it in a mailbox.
For instance, if you drop your tax return into a mailbox on April 15 (aka tax day), but USPS doesn’t process it until April 16, then April 16 will be your postmark date. In this case, the IRS could see this as a late filing even if you put your return in the mail on time with enough postage.
What’s the IRS postmark rule?
Under current IRS code 7502, the IRS treats a return or any other mailing or payment as being filed or mailed on time if it was postmarked by the deadline, even if it arrives late. In other words, the postmark date is the date they look for to determine whether you sent your filing or payment on time.
How does the new USPS postmark rule impact my tax filings or payments to the IRS?
Although this change may seem subtle, depending on your situation, the impact on deadlines and penalties could be significant. Some things to consider:
- Late Filing Penalties: If your return is deemed late, you could face failure-to-file penalties and interest on any taxes owed.
- Late Payments: The same timing issue could apply to mailed tax payments and could result in a higher tax bill.
- Extensions and Claims Denials: Extension requests and refund claims must also meet deadlines to avoid denials and penalties.
How can I avoid timing problems even under the new USPS postmark rule?
There are clear, practical ways to avoid late mailings to the IRS. Here’s what I recommend:
- File Electronically: You’ve probably already thought of this, but you should definitely file electronically whenever possible. E-filing with the IRS gives you an instant timestamp, and there’s no mail, mailroom processing, or postmark guessing that needs to take place. This is the safest way to make sure your filing or payment gets to the IRS on time.
- Certified or Registered Mail: The next best thing is to use certified or registered mail. These services will give you a receipt with the date you actually mailed the item, and under IRS rules, a USPS employee-stamped certified receipt is recognized as proof of mailing. This is especially helpful when you still want to send mail but you’re also down to the wire.
- Manual Postmark: You can also ask for a manual postmark free of charge if you go into a staffed USPS location. This manual postmark will match the day you are there and not the day the machine processes your mail.
- Contact a Professional: Working with a CPA or bookkeeper (if you’re a business owner) is the best way to make sure that you never miss important tax-filing deadlines!
Abridged by Amy
The new USPS postmark rule doesn’t change IRS deadlines, but it does change how the mailing date is recorded, so if you’re cutting it close, you could wind up with penalties you hadn’t expected.
Consulting a CPA can help you map out a plan and make sure that your important documents and filings don’t get tripped up by a delayed postmark. Remember that the goal isn’t perfection; instead, you should focus on staying compliant, avoiding penalties, and working with professionals to help you meet your financial goals.
While you’re here, take a minute to read a couple of my related articles:
