Nearly 150,000 Mail-In Ballots Rejected in California Primaries Amid Postal Service Concerns

California rejected nearly 150,000 mail-in ballots during its primary elections on June 2, 2026, reigniting debate over the security and efficiency of mail-in voting in the United States. Official data from the California Secretary of State, analyzed by the Associated Press, revealed that 148,241 ballots, or 1.73% of all mail-in votes, were invalidated.

Despite California's relatively flexible system for mail-in ballots, which automatically sends them to all registered voters and allows them to arrive up to seven days after Election Day if postmarked by the deadline, most rejections were attributed to issues with the U.S. Postal Service (USPS) or late submissions. Specifically, 93,479 ballots were invalidated for arriving past the deadline or bearing postmarks dated after June 2, 2026. This figure represents an increase compared to previous primaries, with 108,982 rejected in 2024 and 105,818 in 2022.

Kim Alexander, president of the California Voter Foundation, suggested that the issue often lies not with mail delivery times but with the postmark date itself. She noted that ballots rejected for lateness are frequently due to late postmarking, rather than late arrival. This concern is compounded by recent modifications within the USPS, which some federal senators have flagged as potentially impacting postmark accuracy. New procedures may result in postmarks reflecting the date of processing at a sorting facility, not necessarily the date the ballot entered the postal system.

To mitigate these risks, election authorities have advised voters to submit their mail-in ballots several days before the deadline. Beyond timing issues, other reasons for ballot rejection included missing signatures and inconsistent voter information, though these constituted a smaller portion of the total invalidations. Data indicates that areas like Tu, Alpine, and Merced experienced higher rates of rejected ballots.