Banks paid out £116.4m in redress for interest rate swap misselling last month, taking total payouts to £598.4m.
The latest FCA data, published this week, shows £116.4m was paid to 1,143 customers in March for missold interest rate swaps.
A total of 4,573 customers have received redress since the scheme launched last August, with 1,485 claims rejected.
About 18,800 customers have been invited to join the review to date, of which 84 per cent opted in.
Royal Bank of Scotland has the highest number of affected customers with 4,195 at redress stage. HSBC has 2,295 at redress stage, Barclays has 1,801 and Lloyds Banking Group has 1,092. Other banks account for 375 redress offers.
The FCA says the banks remain on track to provide a redress determination to all customers within 12 months of starting their reviews and will continue to send out final reminders to customers over the next few months.
The regulator first raised concerns about the ways banks sold interest rate swaps in June 2012 after a review found high levels of non-compliance. As a result, the banks agreed to review the sale of interest rate swaps, which are designed to protect consumers against increases in interest rates.
More than 30,000 sales are being reviewed, dating back to 2001.