The bank charges reclaiming campaign has saved consumers almost a billion pounds a year in lower fees, the Office of Fair Trading has said.
The watchdog revealed the boon as it also slammed banks for failing to make the current account switching process simpler (see the Bank Switching MSE News story).
The bank charges campaign, with Money Saving Expert at the forefront, has led to up to £928 million a year in savings from the subsequent fall in unauthorised overdraft charges between 2007 and 2011.
In addition, before a hold was placed on reclaiming in 2007, consumers got back hundreds of millions of pounds in unfair fees.
Banks eventually won a landmark court battle in 2009 which ended mass reclaiming of charges, but those in hardship can still get their money back. See the Bank Charges Reclaiming guide.
Money Saving Expert news editor Guy Anker says: "Our bank charges reclaiming campaign not only helped people get hundreds of millions of pounds back in unfair charges, but it has forced banks to lower these sometimes hideous fees for the long term.
"Banks may have won the court case to stop mass reclaiming, but the benefits of the campaign are there for all to see."
Over the past few years, banks have scrapped most of their huge fees for breaching overdraft limits, many of which were up to £35 per bounced payment.
Many now have daily fees. For example, Halifax charges £5 a day when a customer goes over their limit on a standard account.
Despite the fall in fees, the OFT says overdraft charging structures remain too complex.