TFC07100 - Persons not treated as being in the UK: person not ordinarily resident in the UK
Childcare Payments (Eligibility) Regulations 2015, regulation 7(3)
Persons in the UK but not ordinarily resident in the UK are treated as not being in the UK, unless they are subject to certain refugee, immigration, humanitarian, or discretionary provisions (see TFC06300 - Exceptions to the ordinarily residence rules).