The intermediary lender of the Co-Operative Bank will move its pre-completion service to its mortgage processing centre in Leek and its customer care service to its service centre in Stockport.
All other Platform functions will continue to be based in London.
The changes will be phased to protect service levels and the exact dates of these changes are still to be confirmed.
The lender said it made the changes so it could grow its intermediary mortgage business by having access to the correct people with skills and experience in mortgage processing and customer service.