Bank of America says its website is back to normal after technical problems caused two days of sporadic outages for users over the weekend.
The website went down after the bank informed its customers they were going to charge a new $5 a month debit card fee.
Bank spokeswoman Tara Burke said the website is now fully operational. She said the recent problems were not the result of hacking and no customer information was compromised.
Bank of America, based in Charlotte, N.C., is the biggest U.S. bank by deposits. The bank said new regulations have forced the charges.
Wells Fargo and Chase banks have also experimented with similar fees.
"All sorts of banks are trying all manner of new fees. Really it feels like they've turned into airline industry trying to nickel and dime you at every turn," said Bob Sullivan, author of Gotcha Capitalism.
Consumer experts say fewer banks are offering free checking and more are requiring minimum balances.
The best solution is to keep all your accounts at a single bank, so both checking and savings count toward your minimum required balance.