Complaints about mortgages rose by 3.9 per cent year-on-year in the second half of 2014, according to the FCA.
There were 78,537 complaints about mortgages between 1 July and 31 December 2014, up from 75,578 over the same period a year earlier.
Complaints against banks increased by 1 per cent for H2 2014. The data shows a 2 per cent increase between H2 2013 and H2 2014 when payment protection insurance data is omitted.
Total redress also rose for the period, by 4 per cent to £2.44bn, with 88 per cent of this due to insurance and pure protection products, including PPI.
Barclays topped the complaints list despite a 1 per cent fall since H1 2014. It was followed by Lloyds Bank, Bank of Scotland, HSBC and NatWest. HSBC received the only rise in complaints among the top five, at 16 per cent.
FCA director of strategy and competition Christopher Woolard says: “[The] statistics offer a mixed picture. When you take PPI out of the equation, complaints are still on the up. So while the overall decreases should be welcomed, there is still more for financial services firms to do.”