The final amount due for financial mis-selling would be even more if consumers reclaimed what is owed for mis-sold endowment mortgages and savings and investment products, said EMCAS.

Almost 11 million Brits are unsure if they can claim for financial mis-selling or have no idea if they have been mis-sold to, said the firm.

Those who have been mis-sold to but have yet to make a claim could be missing out on substantial amounts – the average payout for a claim about mis-sold PPI is £2,6503.

EMCAS said its research showed consumers who are making claims are experiencing delays as banks refer increasing numbers of cases to the Financial Ombudsman Service.

David Walter, spokesperson for EMCAS said: “Our primary concern remains that victims of financial mis-selling reclaim what is rightfully theirs. The voice of consumers needs to be heard above that of the banks.

“Our evidence shows that there are still significant sums of money due in compensation but 17% of consumers aren’t sure if they are a victim of financial mis-selling.

“We encourage them to check and be sure. Whilst consumers may face a number of obstacles when making a claim we urge them to persevere to right these wrongs.”

According to EMCAS’ research, 31% of consumers are confused about whether they can make a claim or not, and 28% have not thought properly about whether they have a claim.

A quarter said they do not feel they have enough knowledge to make a claim on their own and 22% said they do not have enough time.