USPS Postmark Changes: Don't miss your tax deadline

Effective Dec. 24, 2025, USPS will define the postmark date as the date of first automated processing, which may be later than the drop-off date. Because tax filings are considered timely only if postmarked on or before the due date under IRC §7502, taxpayers should mail documents at least two days early or obtain a manual postmark at a USPS retail counter, or use Certified or Registered Mail. For example, dropping mail in a box at noon on the 15th could result in a postmark of the 16th if it isn’t processed until the next day.

mailing tax documents