Nearly 150,000 California Mail Ballots Rejected In Primary

California election officials are examining why nearly 150,000 mail-in ballots were rejected during the state’s June primary, with late-arriving ballots accounting for most of the increase.

The higher rejection rate comes despite years of election law changes designed to make voting more accessible and ensure more ballots are ultimately counted.

According to data compiled by the California Secretary of State’s office, 148,241 mail-in ballots were rejected during the June primary, representing 1.73% of all mail ballots returned.

That marks an increase from the 2024 primary, when 108,982 ballots were rejected, or 1.56% of all mail ballots cast.

The largest reason for rejection was ballots arriving too late to qualify under California law.

State data shows that 93,479 ballots were rejected because they failed to meet the state’s deadline requirements.

California allows mail ballots to arrive up to seven days after Election Day, provided they are postmarked on or before Election Day.

Voting experts believe many of the rejected ballots received postmarks dated after Election Day, making them ineligible to be counted even if they arrived within the seven-day grace period.

Kim Alexander, president of the nonpartisan California Voter Foundation, said the timing of postal processing appears to be a significant concern.

“Ballots rejected due to lateness are caused primarily to being postmarked too late to count, not because they arrived too late to count,” Alexander said.

Election experts have questioned whether recent operational changes within the U.S. Postal Service may be contributing to delayed postmarks.

Earlier this year, a group of mostly Democratic U.S. senators wrote to the Postal Service expressing concern that mail-processing changes could affect ballot handling during federal elections.

Updated Postal Service procedures mean postmarks may reflect when mail is processed at regional facilities rather than when it first enters the mail system.

Because processing centers have been consolidated in some areas, election officials have warned that postmark timing could be affected.

Before the June primary, California election officials encouraged voters to mail ballots as early as possible because of potential postal delays.

The June election also featured a highly competitive race for governor, which some experts believe encouraged many voters to wait until the final days before casting ballots.

In addition to late-arriving ballots, approximately 44,000 ballots were rejected because election officials determined the voter’s signature did not match the signature on file.

Another 8,300 ballots were rejected because the return envelope did not contain a signature.

State records also show that 743 ballots were rejected because those voters had already cast another ballot.

Other rejected ballots involved missing ballots inside return envelopes or multiple ballots submitted in a single envelope.

The highest rejection rate in the state occurred in Tulare County, where 3.52% of returned mail ballots were rejected.

Alpine County and Merced County followed closely, each recording rejection rates of 3.36%.

California has frequently faced criticism for taking weeks to complete vote counting after major elections, largely because state law permits ballots meeting certain requirements to continue arriving after Election Day.

Following the June primary, President Donald Trump again criticized California’s election system, while the Department of Justice opened an investigation into election administration in Los Angeles County.

Election experts emphasize that the increase in rejected ballots should not be interpreted as evidence of widespread voter fraud.

A 2025 report by the Brookings Institution found documented cases of mail ballot fraud remained extremely rare, estimating roughly four cases for every 10 million mail ballots cast, The Associated Press reported.

State officials have not identified evidence of widespread fraud connected to the June primary, but the increase in rejected ballots is expected to receive additional scrutiny as election administrators evaluate whether changes in postal operations, voter behavior or election procedures contributed to the higher rejection rate.