Mutuality of Obligations in its simplest terms this means that the client is obliged to continue offering you work and you are obliged to continue accepting the work offered.

Mutuality of obligation (MOO) is one of the three factors that will be considered at an IR35 (off-payroll rules) employment status test that a tax tribunal or court would use to establish whether a contractor is in fact a ‘disguised employee’ and, therefore, subject to the provisions of IR35.