Nearly half of all complaints to financial services firms in the second half of 2017 related to advising, selling or arranging.
This was the single biggest cause for complaints, with 49 per cent lodged for this reason - up from 43 per cent in the previous six months - compared to 34 per cent for general administration or customer service.
The increase in the proportion of complaints falling into the advising, selling or arranging category was driven by the increase in payment protection insurance (PPI) complaints.
Complaints about PPI drove a 13 per cent increase in the number of complaints made to firms, according to figures released today by the Financial Conduct Authority.
During the second half of 2017, 3.76m complaints were received, an increase of 427,032 on the first half of the year.
Complaints about PPI rose by 40 per cent to 1.55 m, the highest level of complaints about PPI for more than four years, which follows the FCA's public awareness campaign of the looming deadline, featuring Arnold Schwarzenegger's head.
Christopher Woolard, executive director of strategy and competition at the FCA, 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."
Excluding PPI the number of complaints received by firms was 2.21m, around 13,000 fewer than the previous six months.
Of the advice firms featured in the list, St James's Place received the most complaints. Its two arms - St James's Place UK and St James's Place Wealth Management - received 1,503 complaints between them, most of them related to decumulation and pensions.
But this only translated to 4.3 complaints for every 1,000 decumulation and pension policies sold.
Meanwhile Sesame, which is owned by Aviva, received 649 complaints, with 244 of these relating to investments, despite the network closing its wealth management arm in 2015 amid regulatory action. A further 276 complaints against Sesame related to insurance and pure protection.
Online investment broker Hargreaves Lansdown received 1,839 - mainly relating to investments.
The investment provider with the most complaints was Barclays, with 9,136 while the pension provider with the most was Prudential with 7,278. Meanwhile in terms of home finance, the most complained-about lender was Bank of Scotland, with 22,828.
But these providers change when broken down by the amount of business they do. Alliance Trust Savings received the most complaints about decumulation and pensions per 1,000 policies in force, with 26.4.
Meanwhile closed book provider Phoenix received 77.1 investment complaints per 1,000 client accounts, which was the most in the industry. The mortgage lender with the most complaints per 1,000 balances outstanding was Blemain Finance, which is owned by Together, with 43.1.
damian.fantato@ft.com
