Undeliverable rates can vary widely by county and election

Votebeat collected data on the share of mail ballots that were returned as undeliverable in Arizona's primary election in each county from Aug. 6 to 13, 2026. The final number of undeliverable ballots may be slightly higher than represented in these figures, as sometimes returns from the U.S. Postal Service are delayed. The federal government collects data on undeliverable ballots after each general election.

*County provided a "2026 PE Total Mail Ballots Sent" figure that included ballots issued in person during early voting.
**County provided a "2026 PE Undeliverables" figure that included both ballots returned by the Postal Service and ballots returned in person by voters who said the ballot was sent to them in error.
Chart: Thomas WilburnSource: U.S. Election Assistance Commission, Arizona county recorders