Wells Fargo customers in six states who had free checking accounts will pay $7 a month starting in May.
The bank said Thursday that it started moving customers in 23 states to the $7 fee last year and is expanding to six more _ Georgia, New Jersey, New York, Connecticut, Delaware and Pennsylvania.
Customers can avoid the fee by keeping a minimum balance of $1,500 or making direct deposits of at least $500 a month. They can also get a $2 break on the fee by opting for online statements.
Wells Fargo says it hasn't offered free checking to new customers since 2010. The bank, based in San Francisco, has branches in 39 states. It will expand the fee to all 39, but a spokesman said the bank had not determined when.
Banks have been adding and experimenting with fees in recent months. They say they need to make up lost revenue, partly because of regulatory changes. Banks have been barred from changing interest rates on credit cards without notifying customers, for example.
For customers, the fees add up. NerdWallet, a personal finance site, said it found that customers who can't meet the minimum balance and other requirements are charged an average of $110 a year by the five largest banks.
At a time when the country is struggling with 8.3 percent unemployment, the fees have consumer advocates outraged.
"Banks don't realize they are going to lose much more in the way of lost customers than they are going to make on these ridiculous fees," said John Tschohl, a customer service expert who consults with banks.