Proposition 39: Voter IDID to vote in person, ID numbers on mail ballots, and citizenship checks
Read the full text of the measure: Official Voter Information Guide (PDF)
In plain words
Today California checks who you are by your signature: you sign the roster at the polls, or sign your mail ballot envelope and officials compare it to your record. This would require a government-issued ID to vote in person, and the last four digits of your chosen ID number written on your mail ballot envelope, matched to your record. The state must give a free voter ID card to anyone who asks and must use government data to check that voters are citizens. The Legislature would still have to decide which IDs count. (lao.ca.gov (Legislative Analyst's Office) )
Before and after
| Question | Today | If it passes |
|---|---|---|
| Voting in person | Sign the roster; ID usually not asked | Show government-issued ID |
| Voting by mail | Sign the envelope; signature checked | Also write last 4 digits of your ID number, matched to your record |
| Free state voter ID card | No | Yes, on request |
| Citizenship checks | Citizenship required; sworn on registration | Officials must make "best efforts" to verify with government data and report yearly |
| Audits | None of this kind | State Auditor reports every odd-numbered year |
Numbers from the official ballot title (ballot title ); also see (lao.ca.gov (Legislative Analyst's Office) )
Biggest change
- Mail ballots would need the last four digits of a government ID number on the envelope, matched to registration records; in-person voters would show ID. source: lao.ca.gov (Legislative Analyst's Office)
- A mail ballot would not count if the last four digits do not match the ID number chosen in the voter's registration (for example, a Social Security number on file but driver's license digits on the envelope). source: sos.ca.gov (Official Voter Information Guide)
Who it affects most: The about 13 million people who voted by mail in Nov. 2024 (of about 16 million voters), and voters without a driver's license or other ID.
Cost to the state: State and local costs of tens of millions to low hundreds of millions of dollars each year (Legislative Analyst).
Our plain-words summary. Every line points to its source.
What your vote means
You would show government ID to vote in person and write the last 4 digits of an ID number on your mail ballot envelope.
Voters keep proving who they are by signature, with no ID number needed on mail ballots.
Our one-line summary. The official "What your vote means" statements are in the Secretary of State's Official Voter Information Guide, linked below.
Why people want it, and why others object
Why this is on the ballot
Voters put this on the ballot by signing a petition. It changes the state constitution, so only another statewide vote can change it back. It passes with a simple majority.
- Conservative groups placed this initiative on the ballot. Supporters say most states require some form of voter ID. source: CalMatters
Why supporters want it
- Official argument in favor: "Voter ID is a common-sense reform to increase trust and participation in our elections." Supporters say it keeps mail voting and guarantees a free ID. Signed by Margit Whitlock, Tafa Jefferson and Joe Green, coalition chairs of Californians for Voter ID. source: voterguide.sos.ca.gov (Secretary of State)
Why opponents object
- Official argument against: "Get one digit wrong, and a valid ballot could get thrown out." Opponents also raise identity-theft risk and cost. Signed by David Trujillo (ACLU California Action), Darius Kemp (Common Cause) and Lorrel Plimier (League of Women Voters of California). The rebuttal is signed by U.S. Sen. Alex Padilla and others. source: voterguide.sos.ca.gov (Secretary of State)
Who backs each side
- For: The Transparency Foundation, Latino American Political Assn, Howard Jarvis Taxpayers Assn, CA Women's Leadership Assn, California Republican Party, Reform California, Uline CEO Richard Uihlein. Against: ACLU California Action, Common Cause, League of Women Voters of California, California Democratic Party. source: CalMatters
- Money (Secretary of State, through Aug. 2, 2026): "Californians for Voter ID, Yes on 39" reported $15,167,145. Opposing committees reported $524,847 (Californians for Voting Rights) and $0 (VoteRiders Committee). source: sos.ca.gov (Secretary of State)
In each side's own words where we could find them, quoted or summarized with a link to the source. We don't endorse either side.
What you will see on your ballot
Official ballot wording, word for word (tap to open)
The official ballot title, word for word from the Secretary of State's Official Voter Information Guide .
PROHIBITS CITIZENS FROM VOTING UNLESS THEY PRESENT GOVERNMENT-ISSUED IDENTIFICATION. INITIATIVE CONSTITUTIONAL AMENDMENT.
YES
NO
Official title copied word for word from the Official Voter Information Guide (page 48). The title and summary are prepared by the Attorney General.
Official summary by the Attorney General (tap to open)
Prohibits voting by mail unless voter designates a government-issued identification number for their voter registration. Invalidates mail ballots if envelope does not include last four digits of a government-issued identification number matching the number designated in the voter’s registration (e.g., if voter designates Social Security number for registration, but provides driver’s license number on envelope, their ballot would not count). Prohibits voting in person without presenting government-issued identification. Requires elections officials to annually report percentage of each county’s voters whose citizenship status they have verified.(sos.ca.gov (Official Voter Information Guide) )
Latest news
Recent reporting from a range of outlets, newest first. We link to it; we don't endorse it.
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Full text of the measure
The full text of the proposed law is printed in the Official Voter Information Guide. Read it in the Official Voter Information Guide (PDF) .
Read more
- Secretary of State: Official Voter Information Guide, Nov. 3, 2026 (PDF)
- Official Voter Information Guide: Proposition 39
- Official arguments and rebuttals
- Legislative Analyst's analysis
We link to analysis from several sources; we don't endorse it.