At a time when moves are under way to make it easier for people to switch current accounts and encourage competition, a Which? survey in February said two-thirds had complained, which would equate to around 8million people.
Common problems included poor customer service, incorrect charges, difficulty getting through to someone and mistakes showing up on statements.
Nearly a third of complainants said they had to contact their lender more than once before the issue was put right with Lloyds TSB having the highest proportion of customers saying they had experienced some sort of problem, at 30 per cent, followed closely by its sister bank Bank of Scotland, as well as the Co-operative Bank.
Which? executive director, Richard Lloyd said: ‘There’s been a lot to complain about in banking over the last few years and to win back our trust they must sort out their complaints handling.
‘When things go wrong it is critical that banks act swiftly and fairly to deal with the problem, identify what caused it and make sure it’s not repeated. The way that a bank deals with complaints says a lot about the culture of the organisation. Some banks are getting this right but they all need to do more to put their customers first.’
Lloyds Banking Group said it was ‘disappointed’ to see the Which? findings, particularly as it has reduced its number of complaints last year by 28 per cent. A spokeswoman said: ‘Our commitment to service is central to our aim of being the best bank for our customers. To do this, we’ll continue to listen to our customers’ feedback, focus on their needs and fix the cause of complaints and urge any customer who has an issue with their account to contact us.’
Richard Lloyd of Which? said: ‘There’s been a lot to complain about in banking over the last few years and to win back our trust they must sort out their complaints handling’
The Co-op Bank also said it was disappointed, adding that the findings do not reflect its experience with customer satisfaction surveys or complaints.
A statement from Co-op said: ‘Despite the very low sample size of our customers in this survey, we are not complacent about the findings or our position and we do take any feedback on our customer service extremely seriously.
‘We are now working with Which? to understand the research in more detail and will be addressing those areas in which we have fallen short as a priority.’
Some providers said that the findings did not match with their own experience of customer satisfaction levels and suggested this may be due to relatively small sample sizes being used in the Which? research.
The British Bankers’ Association (BBA) said that moves are already under way which mean that any problems consumers have will be picked up sooner.
A spokesman for the BBA said: ‘Banks take complaints handling seriously and are introducing initiatives to improve the service they offer customers such as the introduction of professional qualifications for complaints handling staff.