When the Mailbox Is No Longer the Deadline

New USPS Postmark Procedure May Affect Time-Sensitive Legal Documents

Starting Dec. 24, 2025, the United States Postal Service began postmarking letters and packages with the date they were processed at a postal facility rather than when they were dropped off at the mailbox.

The shift means lawyers facing mail deadlines could find themselves with something marked as late even if they dropped it off on time. This new postmark process could also lead to late fees and penalties when mailing time-sensitive documents.

The change, designed to streamline processing and save money, could have a huge impact on legal documents such as notices or filings deemed filed or given when postmarked, and other items such as bill payments, mail-in ballots and tax returns. While most filings are now done by attorneys electronically, a large number of contracts and other non-court filings reference the “Mailbox Rule” or a notice’s postmark.

Keep in mind that some mail and packages will not reach USPS processing machines until the day after they are collected by a carrier or dropped off at a Post Office.

The USPS released this announcement regarding their new service standards.