The number of banking complaints stood at 812,197, a 10 per cent decrease on the previous half year and is 22 per cent down on a year ago.

The past year has seen a number of the UK’s largest banks take heavy charges related to expected compensation payments linked to payment protection insurance policies which had been sold and which were subsequently the result of widespread controversy.

There were a total of 531,667 complaints related to PPI mis-selling in the first half of this year, the FSA said, compared with 433,566 complaints in the preceding six-month period.

On structured products – a staple feature of some wealth management offerings – there were a total of 1,219 complaints, a slight fall from 1,352 in the previous half-year period, the FSA said.

Among individual firms, one of the largest number of complaints opened - 162,611 - was Barclays, which had been one of those banks affected by the PPI affair. HSBC had more than 691,000 banking complaints opened; at Lloyds Banking Group, more than 678,000 banking complaints opened.

The total amount of redress paid decreased by 11 per cent from £459 million in 2010 H2 to £409 million in the first half of 2011. Within this, the decrease of 18 per cent in redress paid for general insurance and pure protection will also have been affected by firms placing some of their PPI complaints on hold during the judicial review, the FSA said.

The statistics only cover reportable complaints - those which have not been resolved by close of business on the business day following their receipt. A complaint is resolved when the complainant has indicated acceptance of a response from the firm, with neither the response nor acceptance having to be in writing.

The FSA introduced a new reporting requirement on firms in August 2009 to make the process more useful and less costly for businesses, which means some data from the second half of 2009 onwards may not be strictly comparable to earlier figures, the FSA said.