Nearly 150,000 California Mail Ballots Were Rejected — And USPS Changes Are Raising New Questions
Nearly 150,000 California Mail Ballots Rejected in June Primary as Late Ballots Drive Increase
California election officials are facing renewed scrutiny after nearly 150,000 mail-in ballots were rejected during the state's June primary, with late ballots accounting for the largest share of rejected votes.
According to data compiled by the California Secretary of State's office, 148,241 mail ballots were rejected, representing about 1.73% of all mail ballots returned in the election.
The figure is up from the 2024 primary, when 108,982 mail ballots were rejected, or approximately 1.56% of returned mail ballots.
The increase is drawing attention because California has spent years changing its election laws and procedures to make voting more accessible and give voters additional opportunities to have their ballots counted.
Yet the latest numbers show that tens of thousands of voters still had their mail ballots excluded from the final count.
Why Were So Many California Mail Ballots Rejected?
The single largest category involved ballots that failed to meet California's deadline requirements.
State election data shows that 93,479 ballots were rejected because they were considered too late.
California gives voters a seven-day window after Election Day for a mail ballot to arrive, provided the ballot is postmarked by Election Day or otherwise meets the state's requirements.
That distinction is important.
A ballot can physically arrive within the seven-day period and still be rejected if its postmark does not satisfy the legal deadline.
Kim Alexander, president of the nonpartisan California Voter Foundation, said the timing of postal processing appears to be an important factor.
As Alexander explained, ballots rejected for lateness are primarily a problem of being postmarked too late rather than simply arriving too late.
That has raised questions about how changes in postal operations may be affecting election mail.
Could Postal Service Changes Be Playing a Role?
Election experts have questioned whether recent operational changes within the U.S. Postal Service could contribute to delays in the processing and postmarking of ballots.
Earlier this year, a group of mostly Democratic U.S. senators sent a letter to the Postal Service expressing concerns about mail-processing changes and their potential effect on election mail.
Under updated procedures, postmarks can reflect when mail is processed at a regional facility rather than precisely when it first entered the postal system.
That distinction can matter in an election where the postmark date determines whether a ballot qualifies to be counted.
The consolidation of some mail-processing facilities has also prompted concerns among election officials about whether ballots could experience additional delays before receiving a postmark.
California officials anticipated the possibility of postal delays before the June primary and encouraged voters to mail their ballots as early as possible.
Signature Problems Also Rejected Thousands of Ballots
Late ballots were not the only reason votes were rejected.
Approximately 44,000 mail ballots were rejected because election officials determined that the voter's signature did not match the signature on file.
Another 8,300 ballots were rejected because the return envelope was missing a signature.
State records also show that 743 ballots were rejected because the voter had already cast another ballot.
Other rejections involved ballots missing from return envelopes or situations in which multiple ballots were submitted in a single envelope.
Each category represents a different election-administration issue, meaning the overall rejection figure cannot be attributed to a single cause.
Which California Counties Had the Highest Rejection Rates?
The rejection rate varied significantly across California's counties.
Tulare County recorded the highest rejection rate at 3.52% of returned mail ballots.
Alpine County and Merced County followed, with each reporting a rejection rate of 3.36%.
Those differences have prompted additional questions about local election administration, voter behavior, postal service conditions and the circumstances surrounding ballot returns in different parts of the state.
However, a higher rejection rate by itself does not establish that election officials improperly rejected ballots or that widespread misconduct occurred.
Did Voter Behavior Contribute to the Increase?
Another factor being examined is when voters chose to mail their ballots.
The June primary included a highly competitive race for governor, and some election experts believe the contest may have encouraged more voters to wait until the final days before submitting their ballots.
When voters wait until the deadline, even relatively small postal-processing delays can become important.
A ballot mailed close to Election Day may still reach election officials within California's seven-day window, but if it receives a postmark after the required deadline, it may no longer qualify.
That creates a narrow margin for voters who wait until the last minute.
Does the Increase Mean There Was Widespread Voter Fraud?
No.
Election experts caution that the number of rejected mail ballots should not be interpreted as evidence of widespread voter fraud.
Ballot rejection and election fraud are two different issues.
A ballot can be rejected because of a missing signature, a signature mismatch, a late postmark or another technical problem without there being any evidence that the voter attempted to commit fraud.
A 2025 Brookings Institution report found that documented mail-ballot fraud cases remained extremely rare, estimating roughly four cases for every 10 million mail ballots cast, according to The Associated Press.
State officials have not identified evidence of widespread fraud connected to the June primary.
Instead, the increase in rejected ballots is prompting questions about whether election procedures, postal operations and voter timing are working as intended.
Why California's Mail-Ballot System Is Under Scrutiny
California is one of the states where vote counting can continue for weeks after Election Day.
That is partly because state law permits certain ballots to arrive after Election Day if they satisfy specific requirements.
The system is designed to give eligible voters additional opportunities for their ballots to be counted, but it also creates a more complicated process for election administrators.
The latest rejection numbers highlight that tension.
On one hand, California has policies intended to make voting more accessible. On the other, thousands of voters can still lose their ballots because of deadlines, signatures or other procedural requirements.
The issue has also become politically charged.
Following the June primary, President Donald Trump again criticized California's election system, while the U.S. Department of Justice opened an investigation into election administration in Los Angeles County.
Those developments are likely to keep California's election procedures in the national spotlight.
What Happens Next?
The latest numbers are expected to receive additional scrutiny as election officials and outside experts examine why the rejection rate increased compared with the 2024 primary.
The key questions are straightforward but consequential: Did more voters wait until the final days to mail their ballots? Did changes in postal processing contribute to late postmarks? Are voters adequately aware of signature and deadline requirements? And are some counties experiencing problems that others are not?
Those questions do not have a single answer yet.
What is clear from the state data is that 148,241 mail ballots were rejected during California's June primary, and the largest category involved ballots that failed to meet the state's timing requirements.
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For a state where millions of voters rely on mail ballots, even a relatively small percentage can translate into a significant number of rejected votes.
As California prepares for future elections, the debate is likely to focus less on the raw number alone and more on what caused the increase — and whether changes to election administration or postal operations could prevent eligible voters from losing their chance to have their ballots counted.
