Voter Registration

Register to Vote


Registering to vote is the first step every citizen takes to become an eligible voter. Once registered, you can begin to strengthen our democracy by participating in elections, working at our polling precincts, and even registering others like yourself to become voters.


Registering to vote is easy. You may register online here: You should provide your California Driver's License/ID number and/or the last four digits of your Social Security number when applying on-line.


You may register by mailing a completed Voter Registration Form to the San Mateo County Registration & Elections Division. Forms are available in person at public libraries, city and county offices, California Department of Motor Vehicles offices, and at U.S. Post Offices, or via on-line download. You may also call our office at (650) 312-5222 and we will mail a form to you within one business day. To pick up a Voter Registration Form in person, look at our index for a location near you PDF


You may register at any time, but to be eligible to vote in an upcoming election, your Voter Registration Form must be applied on-line by midnight no later than 15 days before that election. If you are mailing a Voter Registration Form, it must be postmarked no later than 15 days before that election and received by the San Mateo County Registration & Elections Division by the close of the polls on election day.


Uniformed and Overseas Voters

San Mateo County voters who are overseas or in the military may register and apply for a Vote by Mail ballot by completing a Federal Post Card Application form (Standard Form 76). This form is available at your local US Embassy or by visiting the Federal Voting Assistance Program website at


Once your registration form is received and processed, we will send you a Voter Notification Card within 3 to 4 weeks indicating that you are now a registered voter. You can also check your eligibility online. If you are unsure about your voting status, please call the San Mateo County Registration & Elections Division directly at (650) 312-5222.


Voter Qualifications

You may register to vote if you meet all of the following requirements:


  • Citizen of the United States
  • Resident of California
  • At least 18 years of age on or before election day
  • Not in prison or on parole for the conviction of a felony.

Re-register to Vote

You must re-register to vote if you:


  • change your name
  • change your address
  • want to change your political affiliation (party)

Cancelling Your Voter Registration

If you've moved out of the County or State, please cancel your voter registration.

Just fill out the attached "Authorization to Cancel Registration" form and sign and date it.  You may return it by mail, fax or email it to:

San Mateo County Registration & Elections Division

40 Tower Road

San Mateo, CA 94402


fax:        (650) 312-5348  

If you have any questions, please contact us at (650) 312-5222.  Thank you.