The U.S. Postal Service currently will hand-cancel mail that requires a postmark. So will the Supremes change this?

January 2, 2026

MYTH: How the Postal Service applies postmarks is changing.

FACT: The Postal Service has not changed and is not changing our postmarking practices, which have been consistent since we began moving away from hand-canceling every item at Post Offices decades ago.

-snip-

While we are not changing our postmarking practices, we have made adjustments to our transportation operations that will result in some mailpieces not arriving at our originating processing facilities on the same day that they are mailed. This means that the date on the postmarks applied at our processing facilities will not necessarily match the date on which the customer’s mailpiece was collected by a letter carrier or dropped off at a retail location.

As before, a customer can ensure that a postmark is applied to his or her mailpiece, and that the date on the postmark matches the date of mailing, by visiting a Postal Service retail location and requesting a manual (local) postmark at the retail counter when tendering their mailpiece. Manual postmarks will be applied free of charge.

This guidance is the same for all types of mailpieces, including mail-in ballots. Customers with additional questions about mail-in ballots can visit our Election Mail website: usps.com/voterinfo. (My emphasis)

(Could come in handy at tax-mailing time, too.)

https://about.usps.com/newsroom/statements/010226-postmarking-myths-and-facts.htm