Nearly 3,000 San Luis Obispo County mail-in ballots went uncounted in the June 2 primary election after receiving postmarks dated after Election Day, a sharp increase tied to changes in U.S. Postal Service processing.
According to San Luis Obispo County Clerk-Recorder Elaina Cano, 2,923 vote-by-mail ballots were rejected this primary because they were postmarked after Election Day. That’s up from 782 in the 2024 presidential primary and 1,821 during a 2025 special election.
The trend extends beyond San Luis Obispo County. Nearly 150,000 mail-in ballots were rejected in California’s June primary, according to data from the California secretary of state. More than 93,000 were disqualified because they received postmarks after Election Day, making lateness the leading reason ballots were rejected statewide.
“This is a problem that has been seen throughout the state of California and honestly throughout the rest of the country,” Cano told New Times. “California is not the only state that has seen an uptick in the untimely returns of vote-by-mail ballots.”
In late July, Wisconsin Democrats, U.S. Sen. Tammy Baldwin and Gov. Tony Evers, urged the U.S. Postal Service to address mail delays after hundreds of ballots in the state’s April election arrived too late to be counted.
The June primary underscored how heavily San Luis Obispo County relies on voting by mail. Of the county’s 100,751 ballots cast, 95 percent were returned by mail, while just 5 percent of voters cast ballots in person. The county has 182,126 registered voters.
California law allows vote-by-mail ballots to arrive up to seven days after Election Day, provided they are postmarked on or before Election Day. Ballots bearing postmarks dated after Election Day cannot be counted, even if voters mailed them before the deadline.
Cano said the issue is not that ballots are arriving too late, but that many are receiving postmarks after Election Day because of changes in Postal Service processing.
Updated U.S. Postal Service policy says postmarks may reflect the day mail is processed at a regional facility—not the day it was deposited in a mailbox. As a result, ballots mailed close to Election Day may receive next-day postmarks.
San Luis Obispo County ballots are routed through the Postal Service’s regional processing hub, which is roughly 50 miles away in Goleta, before returning to the county elections office. Cano said they’re often not postmarked until a day—or later—after being mailed.
“It used to be where if a voter put in a ballot—even on Election Day—chances are it was going to get postmarked on Election Day,” Cano said. “Because of this new change in their process, that is how we in the state of California have seen that uptick.”
The growing number of rejected ballots also caught the attention of the San Luis Obispo County Board of Supervisors.
During the July 28 meeting, Supervisor John Peschong asked what could be done to prevent more votes from being discarded.
Cano told supervisors the county has little control over how the Postal Service applies postmarks but has expanded voter education efforts ahead of future elections. Ahead of the November 2025 special election, the SLO County Clerk-Recorder’s Office sent out an announcement urging residents to vote early as “residents more than 50 miles from a postal hub cannot count on their return envelope getting postmarked the day they mail it.”
“We highly recommend that people who want to put it into the mail do so at least a week ahead of time,” Cano said during the Board of Supervisors meeting. “If they do it anytime closer to that, please go into your local post office and get them postmarked there. Watch the clerks do that.”
She said voters who have their ballots manually postmarked at a local post office can avoid delays caused by processing at the Goleta hub. During the June primary, county officials were able to count nearly 100 ballots that initially appeared untimely because they carried timely local postmarks.
Voters who miss that one-week mailing window can use one of the county’s 18 official ballot drop boxes or return ballots directly to a polling place or the county elections office in San Luis Obispo or Atascadero. ∆
This article appears in Education Today 2026.
