SLO County’s last election had a ‘huge uptick’ in rejected mail-in ballots. Why?
San Luis Obispo County saw a massive rise in rejected vote-by-mail ballots after the November special election.
In the 2024 General Election, 0.77% of mail-in ballots in SLO County were tossed out due to tardiness, signature issues or the ballot missing from the envelope.
The following year, that percentage shot up to 2.05%, or approximately 2,398 thrown-out ballots, according to election data from the California Secretary of State’s Office.
San Luis Obispo County Clerk-Recorder Elaina Cano said the U.S. Postal Service is to blame for the sharp uptick in uncounted ballots.
“I don’t think it was anything that our voters did,” she told The Tribune.
Cano said many voters followed what they’ve done in the past and mailed their ballots on Election Day. But in 2025, the USPS changed its policy so that ballots were not necessarily postmarked on the day they were received at the plant.
Ballots must be postmarked by Election Day and received at SLO County’s elections office within seven days of the election in order to be counted.
“If the USPS doesn’t postmark them as timely, then they get rejected immediately,” Cano said. “We don’t open them, we don’t process them, nothing.”
SLO County sees large increase in rejected mail-in ballots
Ahead of the November special election where voters chose whether to redraw several of California’s congressional districts, USPS implemented a change that caused postal delays for rural residents across the state.
According to USPS, it optimized its transportation routes last year, which made it so more mail items were not postmarked on the same day they were sent.
In a joint news release last year, California Attorney General Rob Bonta and Secretary of State Shirley Weber warned voters that ballots mailed from areas more than 50 miles away from one of the state’s regional mail processing centers might not be postmarked on the same day they’re sent.
“This means that, in some areas, ballots dropped off at a post office or mail collection box on Election Day won’t be postmarked until the day after, making them late,” the release said.
San Luis Obispo County’s nearest USPS hub is more than 70 miles away in Goleta.
Due to the distance, Cano said there’s “no guarantee” of when vote-by-mail ballots will be processed and postmarked. According to USPS rules, the postmark date “does not inherently or necessarily align” with the date carriers first get possession of the mail.
Following the November 2025 special election, SLO County saw a nearly 700% increase in late ballots in comparison to the November 2024 general election.
In the past, “we would get late ballots, and there would be a handful of them that weren’t postmarked, but nothing like what we saw in November 2025. ... That was a huge uptick,” Cano said.
The majority of the nearly 2,400 rejected ballots in SLO County last November were thrown out because they didn’t arrive in time.
A total of 1,810 late ballots weren’t counted in 2025, data from the Secretary of State’s Office showed. That was far above the 260 late mail-in ballots in SLO County in 2024.
Last year, around 75% of rejected ballots in SLO County were tossed out due to tardiness, while 18% failed to have a matching signature and 5% had no signature at all.
“Too many people get disenfranchised through this mail issue,” Erin Clausen, the public information officer for the Clerk-Recorder’s Office, told The Tribune.
This election season, Clausen said the county is amping up its messaging on how and when to vote by issuing bilingual public service announcements and posting on social media.
How to make sure your vote is counted in the June primary
Cano recommended that voters mail their ballots at least seven days before the June 2 primary election.
If it’s within a week of the election, she said voters can visit the post office and request a same-day postmark on their mail ballot to ensure their ballot is counted.
However, USPS said it is still delivering mail within the same one-to-five day service standard, a spokesperson told The Tribune. The agency recommended voters mail their ballots in ahead of Election Day as a “common-sense measure.”
Voters also have several options if they prefer not to rely on the U.S. Postal Service. They can currently drop off their ballot at one of several drop box locations in the county or at the Atascadero and downtown SLO elections offices.
On Election Day, voters can also bring their ballot to any polling place from 7 a.m. to 8 p.m.
And if someone wants to ditch their mail-in ballot altogether, that’s also an option, Cano said.
“For those that love the tradition of voting on Election Day, they still can,” she added. “You can still go vote at your poll.”
This story was originally published May 26, 2026 at 9:43 AM.
CORRECTION: This article was updated with further context from the U.S. Postal Service.
