Voters in San Francisco on Tuesday resoundingly approved a referendum to ban automated teller machine surcharges.
With 90% of precincts reporting, accounting for 125,000 voters, the measure was ahead by 62% to 38%.
The California Bankers Association said it would help mount a fight in the courts to block the surcharge ban.
The trade group says the Office of the Comptroller of the Currency has jurisdiction over national banks' ATM fees, not local officials or voters.
The San Francisco measure applies to an estimated 450 ATMs owned by banks, credit unions, and thrifts within the city, but consumer advocates say the initiative will contribute momentum to surcharge-ban efforts elsewhere.
The California Public Interest Research Group says surcharging bilks customers and harms small banks, which have trouble competing against banks with larger numbers of ATMs.
-- Helen Stock