An additional step for each way of voting
If California voters approve Proposition 39 on November 3, an in-person voter would have to present government-issued identification. A mail voter would have to write the last four digits of a selected government-issued identification number on the ballot envelope, and officials would have to match that number to the registration record before counting the ballot.
The legislative analyst also describes a free state-issued voter ID card on request, state and county efforts to verify citizenship status from government data, an annual county verification report and regular State Auditor compliance reviews. The Legislature would have to settle implementation details, including accepted forms of ID.
How that differs from today's checks
California already establishes identity at registration using a driver-license or state ID number or the last four Social Security digits. Voters generally sign a roster in person or sign a mail-ballot envelope, and mail signatures are checked. Some people who did not supply identifying information at registration can already be asked for ID the first time they vote. Those facts make it inaccurate to say the state currently has no voter identity checks.
Proposition 39 would add an identification requirement each time a ballot is cast. According to the analyst, about 13 million Californians voted by mail and 3 million in person in the 2024 presidential election; that history illustrates the scale of administering both paths, not a forecast of 2026 turnout.
Costs and unanswered implementation details
The legislative analyst estimates recurring state and local costs from tens of millions to low hundreds of millions of dollars per year. The exact amount would depend on legislation, the card design, the number of cards requested and agency implementation. The analyst says possible savings likely would not exceed costs.
Supporters argue the added checks would build trust; opponents say they could block eligible voters and expose personal information. Those are campaign claims. The official analysis does not quantify how many eligible ballots would be rejected. Until the election and any implementing legislation, voters should use the existing rules, not assume the proposal is already law.