A growing number of customers are taking their bank or building society to court to recover charges they say are unfair and illegal.
People who stray into an unauthorised overdraft or who cannot honour a direct debit payment are often charged around £30 by their bank.
And if they fail to get their account back in order, these charges can snowball.
The consumer action is being encouraged by numerous websites which publish detailed information on how to reclaim fees going back over the last six years.
They argue the charges do not reflect the true costs banks incur and punish customers.
The banks say their fees are reasonable and in-line with their costs, yet so far they have chosen to refund customers the money rather than defend themselves in court.
Earlier this year, credit card companies were told to halve the default fees they impose on customers who miss monthly repayment dates following an investigation by the Office of Fair Trading.
At that time, the OFT indicated that banks could face similar scrutiny.
So what is a fair amount for the banks to charge? And if they were forced to reduce their fees could this threaten the continuation of free banking for current account customers?
Presenter Lesley Curwen interviewed BBC Radio 4 listeners Craig Walton and Nick Hawkes about their views and debated the issue with a panel of guests.
Lesley was joined by:
Joanna Elson, executive director, British Bankers' Association
Bob Egerton of the consumer website Bank Charges Hell
Phil Middleton, banking expert at Ernst and Young
Presenter: Lesley Curwen
Producer: Jessica Laugharne