Pennsylvania’s mail ballot dating rules have been in flux for years. Here’s what you need to know.

By Carter Walker | May 8, 2026

As some Pennsylvania voters prepare to vote by mail in this month’s primary election, they could be forgiven for not knowing what they need to do with the date line on their ballot envelope.

Court rulings have flip-flopped on the requirement several times since Act 77, the law that implemented no-excuse mail voting, went into effect in 2020. For some elections since then, counties had to reject mail ballots that lacked a proper date; for others, they didn’t.

The rule has resulted in thousands of otherwise qualified ballots being rejected and left many voters confused about what they need to do to have their votes counted.