There were 4.13 million complaints against 3,161 firms, with 98% of complaints being made against 235 firms.
The number of complaints against financial firms increased by 10% in the first half of 2018 from the second half of 2017, figures from the Financial Conduct Authority show.
There were 4.13 million complaints against 3,161 firms, with 98% of complaints being made against 235 firms.
PPI was still the most complained about product, accounting for 42% of all complaints, while current accounts, (15%), credit cards (8%) and motor and transport insurance (6%) were other common areas.
Christopher Woolard, executive director of strategy and competition at the FCA, said: “Firms need to be doing all that they can to reduce complaints. It is clear that firms need to look at the cause of the rise in complaints and address these issues to prevent further increases.
“It should be a priority for firms to ensure good consumer outcomes are achieved and they should be making sure that they are taking the right steps to treat customers fairly.
“We are encouraged to see that figures are showing that more consumers are making a decision on whether to complain about PPI.”
