Citibank is one of the few that said it would not introduce a charge for debit card use. “We have talked to customers and they have made it abundantly clear that ‘if you charge me to use my debit card, I would find that very irritating,’ ” said Stephen Troutner, head of Citi’s banking products. Still, the bank has made it more difficult to qualify for free checking, among other moves.

Earlier this year, Wells Fargo estimated that the Durbin rules would cost the bank $250 million in revenue every quarter. It hopes to make up half that gap with a variety of new products and customer fees, including the monthly debit card fee of $3. The change is part of a “pilot program” the bank will begin on Oct. 14 in five states across the country, including Washington and Georgia. As of Saturday, the bank will discontinue its debit card rewards program.

Meanwhile, HSBC said that it recently increased an A.T.M. fee — to $2.50 from $2 — for certain customers when they used a competitor’s A.T.M. It also recently introduced a debit transaction fee of 35 cents, though the first eight transactions are free.

And at TDBank, customers will now have to pay $2 for using A.T.M.’s outside their network.

“Durbin essentially moves the cost of debit away from merchants, and now it’s more focused on consumers,” said Beth Robertson, director of payments research at Javelin. “There are all sort of things happening where banks are saying, where can we put fees in place for our service to generate revenue or how can we reduce our costs?”

Over the last few years, consumers have increasingly shifted their spending to debit cards from credit cards, in large part to curb their spending. But some analysts predicted that the new fees could prompt consumers to return to credit cards — a more lucrative alternative for the banks.

Consumers have already begun to react to the changes.

Patrick Shields, 48, said he had decided to leave Citibank, where he has held a small-business account for his residential window cleaning business since 1986. He was contemplating opening a personal checking account, but realized he could do better at a credit union.

“At the credit union, they opened it free of charges, which Citi could not and would not do,” said Mr. Shields, who noted that a personal checking account would have cost more than the one he uses for his New York business. “Now I have both accounts covered, and I am fee-free.”