The U.S. Postal Service is making an important change to how postmark dates are determined, and it could affect documents with filing deadlines, including tax returns and payments.
Effective December 24, 2025, USPS machine-applied postmarks will no longer necessarily reflect the date mail was dropped off. Instead, the postmark date will reflect the date of the first automated processing operation at a USPS facility. This processing date may occur one or more days after the item is placed in a mailbox.
For tax filings and payments, documents are generally treated as timely filed or paid only if the postmark date is on or before the applicable deadline. Under the new rule, an item processed after the due date may be considered late (even if it was mailed earlier), unless appropriate proof of mailing is obtained under Internal Revenue Code Section 7502.
Helpful Mailing Tips to Know
If you plan to mail time-sensitive documents, the USPS recommends taking one of the following steps:
- Request a manual postmark by presenting your envelope at a USPS retail counter
- Pay for postage at the counter, which applies a postage validation imprint showing the USPS acceptance date
- Use Certified Mail or Registered Mail, which provides a receipt as evidence of the mailing date
ATA Tip
If mailing is your only option, ATA recommends Certified Mail as the most practical and reliable of the available methods because it provides written proof of the mailing date.
That said, we strongly encourage clients to submit all time-sensitive filings and payments electronically whenever possible. Electronic submission helps reduce delays, provides immediate confirmation, and avoids uncertainty related to postmark processing.
Clients may consider:
- Creating an online account with the Internal Revenue Service at https://www.irs.gov/your-account
- Making a payment directly from a bank account using IRS Direct Pay (no login required) at https://www.irs.gov/payments/direct-pay-with-bank-account
If you have questions about deadlines, mailing options, or electronic filing and payment alternatives, your ATA advisor is happy to help you.