Challenges in California’s Mail-In Ballot Rejections

Nearly 150,000 mail-in ballots were rejected in California during the June primary election. This marked an increase from previous elections amid efforts to ease voting processes and enhance participation. These changes aim to count every ballot received.

California’s voting system is known for its slow counting process, lasting weeks or more. Changes intended to boost turnout have not been effective. Each voter gets a mail-in ballot, considered valid if postmarked by Election Day and received within seven days. Yet, late-arriving ballots remain the main reason for rejections. Data suggests that ballots postmarked after Election Day are ineligible for counting. This may result from U.S. Postal Service changes affecting postmark timing.

Late-arriving ballots drove the rejections.

State data revealed that 148,241 mail ballots were rejected in June. This was a 1.73% rejection rate for all mail ballots. This figure was above 108,982 rejected ballots in the 2024 primary with a 1.56% rejection rate. In the 2022 primary, 105,818 mail ballots were voided at similar rates. Notably, 93,479 rejected ballots in June were due to lateness. Fewer, around 70,000 in 2022 and about 76,000 in 2024, were disqualified for the same reason. More voters waited until the last days of the wide-open race, contributing to the surge in late ballots.

Kim Alexander of the California Voter Foundation highlighted the increase in late rejections as troubling. She emphasized that lateness stems from postmark timing, not actual arrival timing. Mindy Romero from the Center for Inclusive Democracy noted a need to question why rejections due to lateness have risen.

Lawmakers concerned about USPS postmark changes.

In January, mainly Democratic senators expressed concerns to the U.S. Postal Service about mail-processing changes potentially affecting postmark dates. Updated USPS policy indicates postmarks may not reflect the first mail reception day. This results from recent postal center consolidations, potentially delaying postmarks. In response to problems, two Wisconsin Democrats urged the Postal Service to address delays after Election Day ballots arrived late in April.

A federal judge previously halted an order by President Donald Trump to create a federal voter list and limit mail ballot recipients. California election officials earlier advised voters to mail ballots early, warning of potential delays.

In June, Tulare County experienced the highest mail ballot rejection rate at 3.52%, followed by Alpine and Merced Counties with 3.36%. Rejections occurred due to mismatched signatures, signature omissions, multiple ballots in one envelope, or missing ballots. Party registration data was not specified. Despite California’s slow vote counting compared to states like Florida and Texas, there are no widespread issues with mail voting. A Brookings Institution report in 2025 identified minimal mail voting fraud cases, about four per 10 million mail ballots.