If you show up to vote on Nov. 3 and something doesn't match up, you won't be turned away. California law gives you the right to cast a provisional ballot.
What it is
The California Secretary of State says a provisional ballot is a regular ballot that goes into a special envelope before it is put in the ballot box. It is counted after elections officials confirm that you are registered in that county and did not already vote in the election.
Why it exists
The state lists two reasons. First, provisional voting makes sure that no properly registered voter is denied a ballot because a clerical, processing, computer or other error left them off the roster. Second, it lets officials make sure that no one votes twice, on purpose or by accident. California's provisional voting laws have been in effect since 1984.
Where you can use one
You can vote a provisional ballot at any polling place in the county where you are registered. Only the contests you are eligible to vote in will be counted.
When it's counted
Provisional ballots are counted during the 30-day canvass after Election Day, along with same-day registration ballots and late-arriving mail ballots, according to the Secretary of State's vote-counting guide. That is one reason results change after election night.
Checking your ballot
Every voter who casts a provisional ballot has the right to find out from their county elections office whether it was counted and, if not, why. Each county runs a free system for this. Links to each county's system are on the Secretary of State's ballot status page.