"SunTrust does not assess overdraft and returned item fees on any transactions that are less than $5," he wrote.
It said the maximum amount customers would pay in unpaid item fees would fall from £114 a day to £50 a month.
A spokeswoman for Which? said the charges could be even higher if interest payments or possible unpaid item fees were included, or the money was borrowed over two monthly charging periods, because the maximum charge related to the charging period and not how long the money was borrowed for.
Indeed, dealers sometimes add line-item fees on the new car for rust-proofing, paint sealant or prepping to make up the difference of the trade.
Nor does the filter work for laboratory fee items, because fees in these cases may go to a central payee at a central address.
"For purchases of $5 or less that overdraw your account, we'll no longer charge you an insufficient funds fee, returned item fee, or overdraft protection transfer fee".
JPMorgan said that the bank will charge only one returned item fee per lender in a 30-day period when customers do not have enough money in their accounts to cover the withdrawals.
Even after Ms. Yartz paid $100.05 in February to cover the bounced check, the returned item fee and an administration fee, she got a letter signed by the Alameda district attorney informing her that her remaining balance was $180 for the class.
From 1 October the bank will cut the monthly charge for going overdrawn without the bank's permission from £28 to £20, while the "unpaid item fee" - imposed when a cheque, direct debit or standing order bounces - is being chopped from £38 to £5.
However, it is a big change for the millions of standard current account holders, who have got used to a mix of "carrots" and "sticks": a 0.1% in-credit interest rate, agreed overdraft rate of 19.5%, unauthorised overdraft rate of 28.8%, plus various charges such as the "unpaid item fee".
