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HMRC internal manual

National Insurance Manual

Employment Allowance: Who can’t claim the Employment Allowance? Domestic employment

National Insurance Contributions Act 2014 - Section 2, subsection (3)

Secondary Class 1 NICs liabilities arising from the employment of a person who is (wholly or partly) employed for purposes connected with another person’s personal, family or household affairs (eg:- nanny, au pair, chauffeur, gardener) are “excluded liabilities” against which the Employment Allowance cannot be claimed.

However, see also NIM06520 about the employment of care and support workers.