Voting by mail? Why the postmark on your ballot matters this year

If you vote by mail this year, when you send your ballot may matter as much as whether you send it.

Grace periods survived at the Supreme Court

Some states count mail ballots that arrive after Election Day, as long as they are postmarked by Election Day. On June 29, 2026, the Supreme Court upheld that practice in Watson v. Republican National Committee, a case about Mississippi's law, which accepts ballots received up to five business days after the election.

In a 5-4 decision written by Justice Amy Coney Barrett, the Court held that the federal laws setting the date of federal elections govern when voting must happen, not when ballots must be received. According to Voting Rights Lab, 14 states and the District of Columbia have postmark grace periods for this election.

The postmark problem

A U.S. Postal Service rule that took effect on Dec. 24, 2025, states that the postmark date does not necessarily show the first day the Postal Service had the mailpiece. The agency described the rule as a clarification rather than a change in practice, Stateline reported.

That matters in grace-period states: a ballot dropped in the mail before Election Day could carry a later postmark and be rejected.

What you can do

• Mail early. The Postal Service advised mailing completed ballots at least a week before Election Day, according to Stateline.
• Ask for a postmark at the counter. Stateline reported that voters can request a manual postmark, for free, at their local post office.
• Use an official drop box or deliver it in person, if your state allows it.
• Check your state's deadline. Many states require ballots to be received by Election Day, and the postmark does not help.

Rules differ by state. Find your state's official deadlines through vote.gov.