The FCA's Senior Management Arrangements, Systems and Controls Sourcebook (SYSC) was created to encourage firms to vest responsibility for effective and responsible organizations and to create a common platform for organizational and system controls requirements for all firms.
A big component of the SYSC Sourcebook is recordkeeping requirements for records such as conflict of interest records, client communications, business and internal organizational records.
Link to FCA's table of recordkeeping requirements found in SYSC: https://www.handbook.fca.org.uk/handbook/SYSC/Sch/1.pdf
Link to SYSC Handbook: https://www.handbook.fca.org.uk/handbook/SYSC.pdf