In summary Californians who used mail ballots might want to double-check online to make sure they counted—either a missing or a mismatched signature could void their vote.

Millions of Californians dropped off their ballots on Tuesday or mailed them in, but they might want to double-check online—because either a missing or a mismatched signature could void their vote.

Counties are contacting voters because they’re now required by law to do outreach. Still, voters should confirm online that their ballots were tallied. If not, they should call their county election office to be sure their vote counts, said Kim Alexander, president of the California Voter Foundation.

“Voters need to be alert and aware,” she said.

After this year’s June primary, California lawmakers passed the Every Vote Counts Act, which gives voters time to correct a mismatched or missing signature. The law was enacted after a lawsuit was filed by the American Civil Liberties Union of Northern California, which argued that 45,000 ballots were rejected last year because of mismatching signatures.

Already county offices are contacting voters asking them to fix their signature issues, such as this instance detailed by a Shasta county voter.

But other voters found out on their own—by checking themselves—including well-connected Democratic communications guru Roger Salazar.

Later he tweeted a follow-up:

Voters who failed to sign their ballots have eight days after Election Day to make their ballots count.

Voters whose signatures don’t match have two days prior to the certification of an election to fix their ballots, Sam Mahood, press secretary for the Secretary of State Alex Padilla, confirmed in an email. This year, county officials have until Dec. 7 to certify election results. Alexander warned that some counties may certify their results sooner.

As of today, the state still has millions of unprocessed ballots. California’s massive size along with other measures the state takes to count and certify ballots mean the state takes much longer than other states to officially call some contests.