TCTM02301 - Entitlement: WTC entitlement: Qualifying remunerative work
The Tax Credits Act 2002, Section 10.
The Working Tax Credit (Entitlement and Maximum Rate) Regulations 2002, Reg. 4
To be entitled to WTC a person, or either or both persons in the case of a joint claim, must be in qualifying remunerative work (TCTM02400).