The FCA put the double digit increase mainly down to complaints about payment protection insurance (PPI).

During the second half of 2017 a total of 3.76m complaints were received, an increase of 427,032 on the first half of the year.

Complaints about PPI rose by 40% to 1.55m, the highest level of complaints about PPI for more than four years. The FCA has imposed a 2019 deadline
for PPI complaints.

In January firms paid out £415.8m in redress to customers who complained about payment protection insurance (PPI).

This is the highest figure since March 2016 and takes the amount paid since January 2011 to £30bn. 

Elsewhere the figures revealed that complaints upheld about decumulation and pensions had fallen 9% from 68% upheld to 59%.

Upheld complaints about investments rose slightly from 49% to 51%.

Christopher Woolard, executive director of strategy and competition, said: “Having set a deadline for PPI complaints, we are encouraging consumers to decide whether they want to claim, and if they do, to make their complaint as soon as possible, as many already have. 

“We are continuing to monitor and challenge all firms to ensure they maintain the expected standards and are delivering on their commitments to make it easy for people to complain about PPI.

“When PPI is taken out of the mix, the numbers of complaints firms are receiving has remained stable.

“Firms should be doing all they can to reduce complaints and ensure they are treating customers fairly.”

Excluding PPI the number of complaints received by firms was 2.21m, around 13,000 fewer than the previous six months.

After PPI, the next most complained about products were current accounts, with 509,047 complaints and then credit cards with 314,586 complaints.