Complaints about the mis-selling of payment protection insurance (PPI) have reached the half a million milestone, the ombudsman service said.
The Financial Ombudsman Service (FOS) said the fallout from the scandal shows "no sign of slowing", with up to 400 PPI complaints received every hour and complaint volumes already over 140,000 this financial year, compared with just under 158,000 for the whole of 2011/12.
It said the 500,000th complaint was brought to it by a woman from Wolverhampton who was self-employed when she was sold a policy by her bank.
Chief financial ombudsman Natalie Ceeney said: "It's extraordinary that we've today received our 500,000th complaint about PPI - and despite these record numbers, this mis-selling scandal shows no sign of slowing.
"While it's good news that more people know that they can come to the ombudsman, it's clear that unless the banks sort out their complaints quickly and fairly, people will only face increasingly longer waits for justice."
The ombudsman service, which clears up disputes between financial institutions and their customers, said it upholds around seven out of 10 PPI cases in consumers' favour and the typical payout is £2,750.
It said the share of people using claims management firms, which often take a quarter of any payout, has dropped off sharply as consumers are feeling "more empowered".
Half of all the complaints the ombudsman receives are now brought directly by consumers, down from seven in 10 last year.
The FOS recently said it is on course to double the record 165,000 PPI complaints it had anticipated receiving during 2012/13.
PPI is the most complained about product the ombudsman service has ever seen, with mortgage endowments coming second with around 350,000 complaints received.