SAN MATEO COUNTY (KPIX 5) – About 21 million ballots are going out across California this year. That’s one for every registered voter in the state. Most should arrive by the end of this week.

“As you can see by my hair, I’ve lived a lot of years,” said Barbara, dropping off her ballot in San Mateo. “I’ll tell you, the first person I voted for was JFK.”

READ MORE: 1 Dead, 2 Injured In Separate Falls During Phish Concert At Chase Center

The 2020 election is now underway, with a steady stream of ballots arriving Tuesday.

“I would say that the most important thing is to take your time, read the instructions,” says San Mateo County Assistant Chief of Elections Jim Irizarry.

No matter where a voter lives, their ballot will include a set of instructions that must be followed carefully.

In San Mateo, it is “1-2-3.” The first part is to fill out the ballot and to tear off the receipt at the top. The next step is the one that is most likely to get your vote disqualified: If you do not sign your envelope, your ballot will be rejected.

READ MORE: Giants Plan To Exercise Buster Posey's $22 Million Club Option If He Plays Next Year

“Last election, we had over 4,000 challenged ballots,” Irizarry said. “Of those 4,000, 2,000 were no signature on the ballots.”

Step three is mail the ballot in, but a lot of people aren’t taking any chances this year.

“I’ve always voted by mail, for the last 10 years,” Carol said, dropping off her ballot. “But with all the controversy I debated between voting in person and dropping it off personally.”

One after another, voters in San Mateo on Wednesday said they were longtime mail-in voters now opting for personal delivery at a voting center.

MORE NEWS: Santa Rosa Man Sentenced To 16 Years In Prison After 65 Pounds Of Meth Found At His Home

“So I decided I was going to bring it in this year, make sure it got into the right hands, because every vote matters,” Barbara said. “People have to vote. It’s important.”