The percentage of complaints upheld rose from 34% to 37% as the service strived to reduce a pandemic backlog.

There was a sharp rise in the number of claims resolved by firms themselves after a campaign by the FOS to reduce its complaints backlog by encouraging firms to resolve some complaints themselves.

During the second half of 2021 the FOS received 73,200 complaints but in the last two months of 2021 1,243 complaints were resolved ‘proactively’ by firms themselves, the FOS said.

There is also a pipeline of some 5,000 complaints being proactively resolved by firms themselves with details to be published in the January to June 2022 data later this year.

The FOS says it has been pragmatically dealing with a backlog of complaints received during the pandemic and is trying to speed up complaints handling so consumers do not have to wait for long periods for a resolution.

The FOS said: “The initiative built on good practice we have already seen from some businesses and has encouraged firms to do more to help get answers to consumers more quickly.”

Some 216 businesses feature in the complaints data for the second half of 2021 compared to 249 in the previous six-month period.

The banking and credit sectors continue to be the most complained about sectors with a total of just over 46,000 new complaints received in the second half of 2021 compared to a total of just over 73,000 complaints altogether.

Despite this there were still many hundreds of complaints about investment and life and pensions.

In the second half of 2021, for example, Aviva Life & Pensions UK Limited received 321 complaints about decumulation, life and pensions and 51 complaints about investments; Consolidator Phoenix Life Limited received 161 complaints about decumulation, life and and pensions; ReAssure Limited (part of the Phoenix Group) received 326 complaints about decumulation, life and pensions; Scottish Widows received 184 complaints about decumulation, life and pensions and Prudential received 248 complaints about decumulation, life and pensions.

Barclays Bank UK PLC received 114 complaints about investments; Interactive Investor Services Limited received 117 complaints about investments and Hargreaves Lansdown Asset Management Limited received 77 complaints about investments. St James’s Place Wealth Management plc received 46 complaints about investments and 38 complaints about decumulation life and pensions.