The FOS said complaints had previously reached this high in 2018/19 during the payment protection insurance (PPI) issue.

It continued on to say that the caseload this year is 54% higher than the prior year and around half of these complaints were brought by professional representatives. The latter compares to 25% in the prior year, with the growth focused on credit affordability and car finance complaints.

The FOS said it saw a rise in complaints about motor finance commission, fraud and scams, and credit cards.

The top five most complained-about products were hire purchase (motor) at 76,160, credit cards at 60,364, current accounts at 36,221, car or motorcycle insurance at 14,082 and conditional sale (motor) at 11,521.

Sponsored

How to get your first-time buyer clients mortgage ready

Sponsored by Halifax Intermediaries

Mortgage complaints near 7,000

Looking at mortgages specifically, there were around 6,895 complaints during the period.

The majority came from residential first charge mortgages, which made up 5,086 complaints.

This was followed by buy-to-let (BTL) mortgages (consumer or non-consumer) at 778 complaints and then second charge mortgages at 406 complaints.

The uphold percentage was 32% on average, with the range going from 12% to 68%. Some categories did not have uphold rates.

FOS complaint uphold rate at 34%

Overall, in 2024/25, the FOS resolved 227,253 complaints – an 18% increase on 2023/24 – while also reducing its stock of older cases.

The FOS said it had upheld 34% of complaints in the consumers’ favour, which compares to 37% in 2023/24.

Around 27% of complaints brought by professional representatives were upheld, and approximately 37% of cases brought directly by consumers were upheld.

The service added that it also spent time handling thousands of withdrawn and abandoned cases, mainly from professional representatives, noting that it recently brought in charges for professional representatives that bring in over 10 complaints per year.

This aims to “bring better balance to the organisation’s fee model and to encourage representatives to submit better-evidenced complaints, considering their merits more diligently before referring them”.

Jenny Simmonds, interim chief executive at the FOS, said: “Although we resolved thousands of cases last year, we know there’s more to do, which is why we are driving forward ambitious plans to transform our service.

“We are modernising our ways of working, investing in new tools and technologies, and building flexibility into our workforce.

“This modernisation programme, alongside reform to the wider dispute resolution system, will create a trusted and effective financial ombudsman, which in turn enables predictability and the confidence to support a strong economy.”

James Dipple-Johnstone, interim chief ombudsman at the FOS, said: “Financial services have evolved significantly since we were set up 25 years ago. New financial products, the digitalisation of services and an increase in fraud and scams mean that we now see high levels of demand and an increasing number of complex cases.

“That is why we are working closely with HMT Treasury and the FCA to ensure the system – including the vital role our service plays within it – is fit for the future.”