Lloyds Banking Group was the bank most complained about to the independent ombudsman in the first half of this year, but the overall proportion of complaints resolved in favour of the consumer fell.
The Financial Ombudsman Service said there had been a small increase in the number of complaints compared to the second half of 2009, but the average percentage for complaints upheld fell by 9 per cent.
The percentage of complaints for each business varied greatly with 100 per cent of complaints in some cases, and down to 14 per cent at other institutions.
Data for the different banking businesses showed the ombudsman received 22,420 complaints relating to the ten businesses in the Lloyds group, including Halifax Bank of Scotland, and Cheltenham and Gloucester.
This number of complaints was substantially greater than other large banking groups, but the FOS said experts it had consulted were not able to agree how the market share of banking groups should be taken into account when reading the data.
The ombudsman received 6469 complaints about Royal Bank of Scotland, 4031 complaints about HSBC, 9215 complaints about Barclays’ business, and 5372 complaints about Santander.
The Co-operative was complained about 1188 times and the building society Nationwide 1104 times.
Out of the 100,000 companies covered by the FOS, 89 per cent of complaints related to just 160 businesses.
A spokesman for the British Bankers’ Association said: “The UK banking industry manages more than 140million bank accounts and the biggest banks conduct many billions of transactions each year for customers, so it is important to keep these figures in context.
“The more customers a bank has, the more complaints it is statistically likely to get.”
The BBA said banks would be working with the ombudsman to see how its findings could be applied to its own complaint handling process.
FOS chief executive and chief ombudsman, Natalie Ceeney, said the latest data showed that some businesses were really committed to ensuring complaints are handled well and used to improve the service they offer to customers.
“However, the complaints data also shows there is still more that some businesses need to do to ensure that complaints are properly investigated and fairly resolved,” she added.
Later this month the Financial Services Authority is due to publish collated data it has received from banks detailing the complaints they have received for the first half of 2010.
© Fair Investment Company Ltd