UK consumers have just hours left to submit a complaint about payment protection insurance (PPI) before they lose their chance to claim compensation.

The deadline is 11.59pm on Thursday 29 August, and the Financial Conduct Authority is urging people to act now.

“This is the final chance for consumers to think about whether they had PPI and submit a complaint directly to any providers right away … There’s still time to act if you do it now,” said the regulator.

Many of the biggest claims management companies have already stopped accepting PPI claims because, they said, there was a risk they would not be able to register them with the lenders before the deadline.

PPI is Britain’s costliest ever consumer scandal, with £36bn paid out by UK banks to compensate people who bought often-worthless insurance cover, thinking it would help them repay debts in the event of sickness or unemployment. Of the total, £340m was paid out in June alone.

As many as 64m PPI policies were sold in the UK, but very often the cover was mis-sold. Banks and other financial institutions pushed the policies alongside loans, mortgages, credit cards and other deals.

The FCA has been running a campaign to raise awareness of the deadline, leading to a more than fivefold increase in its website users and a near eightfold increase in calls compared with the previous nine weeks. The latest figures show that more than 5.4 million people have accessed its PPI website and it has received more than 102,000 phone calls.

The FCA website includes a list of providers that sold PPI. It can be found at fca.org.uk/ppi/how-to-complain/search-for-provider.