The Financial Conduct Authority (FCA) has written to banks urging them to speed up their review of how interest rate hedging products were sold.
Banks including HSBC, RBS and Lloyds Banking Group have agreed to review sales processes after the regulator identified failings in the way some of these products were sold.
The regulator said: "We have written to the banks to make our expectations clear and agree practical ways to speed up the process."
In order to simplify and speed up the process of compensation, HSBC, RBS and Lloyds BG have agreed to split redress payments relating to the swap and consequential losses.
As part of the redress, banks must ensure their methods were in line with the agreed approach, which included building robus redress models, recruiting and training staff, and clearly communicating with customers.
The FCA's predecessor, the Financial Services Authority, looked at 173 sales to non-sophisticated customers and found that more than 90% of the sales did not comply with at least one or more regulatory requirement.
When banks were asked to undertake a pilot review of their products, the results confirmed the regulator's fears of misselling.
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