The Financial Ombudsman Service (FOS) is reducing its headcount by 150, International Adviser understands.
The job cuts include those in management positions, but staff will have the opportunity to apply for new roles.
The move is tied to the reduction in its work on payment protection insurance (PPI) complaints.
The deadline for people to claim back mis-sold PPI was 29 August 2019.
A spokesperson from the FOS said: “The Financial Ombudsman Service is a customer-led organisation and the size and shape of our service needs to reflect the demand to ensure we provide a cost-effective service.
“We have consistently said that we expect the size of the organisation to reduce as our work on PPI comes to an end following the FCA’s August 2019 deadline to complain.
“We are now consulting staff on the next stage of that process and will continue to work with staff and their representatives going forward.”
The FOS did not confirm what impact the job cuts will have on fees or levies for the advice sector.
Tim Sargisson, chief executive at Sandringham Financial Partners, said: “This is a move which makes little sense and is only likely to compound the issues we currently see with FOS.”
This comes days after the chief executive Caroline Wayman announced she is stepping down from the role on 16 April.