California Faces Challenges with Rejected Mail-In Ballots During Primary Elections

Nearly 150,000 mail-in ballots were rejected in California during the state’s June primary. This marks an increase compared to past elections. Despite efforts to simplify voting and increase participation, slow vote counting is ongoing in the state. Various changes were intended to boost turnout, such as providing every voter with a mail-in ballot. These ballots can be counted if they arrive within seven days postmarked by Election Day. Yet, many ballots still came late, according to the secretary of state’s office.

Voting experts point to postmarks after Election Day as a major issue. This could be linked to changes in the U.S. Postal Service affecting postmark timing. Late-arriving ballots accounted for most rejections. State data showed 148,241 mail ballots were rejected, a 1.73% rejection rate. This increased from 108,982 rejected ballots in the previous election with a 1.56% rate. The 2022 primary saw a similar rate to 2024, with 105,818 ballots voided. Late ballots totaled 93,479 in June, the largest category for disqualification. In contrast, about 70,000 late ballots existed in 2022 and about 76,000 in 2024. Turnout was lower in those years.

Kim Alexander from the California Voter Foundation expressed concern over late rejections and possible links to a surge of late ballots due to postponed decision-making in a competitive governor’s race. Mindy Romero, from the Center for Inclusive Democracy, urged investigation into the growing issue.

In January, Democratic U.S. senators addressed the Postal Service over mail-processing changes impacting postmark dates on ballots. Updated policies indicate postmarks may not show the first receipt day. Instead, they show the processing center day. Center consolidations could also delay postmarks.

In April, Wisconsin Democrats Senator Tammy Baldwin and Governor Tony Evers urged the Postal Service to resolve delays affecting ballot arrival after Election Day. Meanwhile, California officials warned voters of postal changes potentially slowing mail service, urging early ballot submission. In June, a federal judge blocked President Donald Trump’s efforts to create a federal voter list and restrict mail ballots.

Among California counties, Tulare County in the Central Valley had the highest rejection rate at 3.52%. Alpine County, south of Lake Tahoe, and Merced County also had significant rejection rates of 3.36%. Other issues included mismatched signatures, missing signatures, multiple ballots in one envelope, and voters having already cast their ballots. Nearly 44,000 ballots faced rejection due to signature mismatches. More than 8,300 were voided for missing signatures. In 743 instances, voters had already voted.

California’s slow vote count contrasts with states like Florida and Texas. After the June primary, President Donald Trump critiqued California’s vote counting. The Republican’s Department of Justice began examining Los Angeles County’s elections. Mail voting remains popular across parties, despite these challenges. A 2025 Brookings Institution report outlined minuscule fraud rates, finding about four cases per 10 million mail ballots.