This included a 130% rise in complaints about payday loans and a 360% increase in complaints about instalment loans.
In total, 50% of complaints about consumer credit services were upheld in 2018/2019, a slight increase on the 47% upheld in 2017/2018.
The report also highlights a 20-point increase in the number of upheld complaints about current accounts and packaged bank accounts.
While PPI-related complaints remain at high levels with 46% of all new complaints in the year 2018/2019 having a PPI connection, there have been some significant rises in consumer credit complaints.
If we remove PPI from the equation, 33% of all new complaints related to consumer credit products and services such as hire purchase and debt collecting.
Most types of credit complaints have risen between 2017/2018 and 2018/2019, although some exceptions are complaints about credit reference agencies (down 13%), credit broking (down 1%) and debt adjusting (down 18%).
The highest year-on-year rise in the consumer credit category belonged to instalment loans, which rose a whopping 360%.
These loans, which are paid back in a set number of instalments, often have lower interest rates than payday loans and generally offer access to larger amounts of money.
Complaints about guarantor loans have risen by 152% year-on-year which reflects figures published by Citizens Advice in 2015 about the number of guarantors approaching them for advice about the loan they were involved in.
Hire purchase complaints also rose by 54%, although it will be interesting to see how the rent-to-own (RTO) cap that came into force last month will impact this in the future.
The increase in payday loan complaints from 17,256 to 39,715 is especially alarming considering the Financial Conduct Authority's (FCA) focus on improving regulation of the sector.
A notable casualty of their reforms was Wonga which collapsed in 2016. However, other companies have stepped in to fill the gap and have seen their revenue increase.
Our guide to payday loan alternatives shows customers different avenues of finding small or short term loans.
The Financial Ombudsman Service deals with complaints across sectors including credit cards, mortgages, pensions and various types of insurance.
After PPI and consumer credit products, current accounts are the area with the largest share of complaints, taking 9% of the overall figure (20% if we exclude PPI).
Interestingly, although complaints about packaged bank accounts were down by 3%, all other current account complaints recorded a combined rise of 43%.
Packaged accounts received bad press several years ago and banks began setting aside money for compensation.
This decline in complaints could be the natural result of a peak in 2015 which has steadily reduced as customers have exercised their rights to compensation and choice.
Credit cards, motor insurance, mortgages and pensions were also high on the list. Year-on-year, complaints regarding all these services have risen by 26%, 9%, 13% and 42% respectively.
In the pensions category, complaints about SIPPs (self invested personal pensions) have risen by 86% year-on-year.
This fits with the figures released in January by the Financial Services Compensation Scheme (FSCS) which found that payouts for mis-sold pensions had doubled between 2016 and 2018.
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