Financial Conduct Authority (UK) SYSC 18
The Financial Conduct Authority is the conduct regulator for nearly 60,000 financial services firms and financial markets in the UK.
There is a requirement placed on a sub-set of FCA regulated firms (SMCR banking and insurance sector firms) to establish appropriate internal procedures for handling concerns relating to misconduct.
Failure to comply with the requirements of SYSC 18 may call into question the fitness and propriety of the firm or relevant members of its staff.
The specifics are laid out in Senior Management Arrangements, Systems and Controls (SYSC) 18 and can be found here and here