General Discussion

How USPS Postmark Change Could Affect Mail Deadlines
Dates on mail now reflect when it’s processed by the Postal Service, not when it’s dropped off
By Aaron Kassraie

Published December 31, 2025

The U.S. Postal Service (USPS) implemented new procedures for dating mail on Dec. 24, postmarking letters and packages with the date they are processed at a postal facility rather than when they are dropped off in a mailbox — a shift that could affect whether time-sensitive mail is considered on time. 

The USPS says the change is aimed at meeting strategic goals to cut costs and streamline mail processing by concentrating it in a smaller number of facilities. But it could create real challenges for consumers dealing with deadline-driven mail matters this tax season and beyond, from IRS filings and Medicare documents to mail-in ballots and government benefit notices.

Date differences between when a piece of mail is dropped off by the sender and when it is processed and postmarked are likely to “become more common” as the changes roll out, according to USPS.

That means a tax return dropped in a big blue mailbox on April 15 or a vote-by-mail ballot sent on Election Day could still be marked late — risking IRS penalties or a rejected vote — because USPS now postmarks when mail is processed rather than when it is sent. 
How to ensure mail is dated correctly...snip...
https://www.aarp.org/government-elections/usps-postmark-changes/