No, the childcare must be ‘registered or approved’.

This means that, in order to qualify for the Income Tax and NICs exemptions, the childcare must be provided by one of the following:

a childcare provider approved under a Ministry of Defence accreditation scheme abroad

for a child aged three or more but not of compulsory school age, by a school. (A child becomes of compulsory school age on 1 January, 1 April or 1 September next following his or her fifth birthday.)

or, within the different parts of the UK, as follows:

In England only

A person registered under Part 3 of the Childcare Act 2006. This will include persons on the following registers operated by Ofsted

the Early Years Register
the general Childcare Register – compulsory part
the general Childcare Register – voluntary part.

Schools - care provided by the governing body of a school is approved if it takes place
- outside normal school hours (this means the normal hours of compulsory education adopted by the school as appropriate for the age of the child), and
- on school premises or on premises that are covered by the inspection of the whole school activity by Ofsted or the equivalent inspection body for certain independent schools.
Other care providers - a domiciliary worker or nurse from an agency registered under the Domiciliary Care Agencies Regulations 2002 providing childcare in the child’s home.

In Wales only

A childcare provider registered by the National Assembly for Wales (through the Care Standards Inspectorate for Wales)
Out-of-school-hours childcare, provided by a school on the school premises, or by a local authority
A person approved under the Approval of Child Care Providers (Wales) Scheme 2007 providing childcare in the child’s home or, if several children are being looked after, in the home of one of the children
A domiciliary worker or nurse from an agency registered under the Domiciliary Care Agencies (Wales) Regulations 2004 providing childcare in the child’s home
A foster parent under the Fostering Services (Wales) Regulations 2003 in relation to a child other than one whom the foster parent is fostering.

In Scotland only

A childcare provider registered by the Scottish Commission for the Regulation of Care
Out-of-school-hours childcare clubs registered by the Scottish Commission for the Regulation of Care
Childcare provided in the child’s home by, or introduced through, childcare agencies, sitter services and nanny agencies which are required to be registered
A foster carer or kinship carer under the Looked After Children (Scotland) Regulations 2009 in relation to a child other than one whom the foster parent is fostering.

In Northern Ireland only

Childcare registered by a health and social services trust
Out-of-school-hours childcare, provided by a school on the school premises, or by an education and library board
A person approved under the Tax Credits (Approval of Home Child Care Providers) Scheme (Northern Ireland) 2006 providing childcare in the child’s home
A foster parent under the Foster Placement (Children) Regulations (Northern Ireland) 1996 in relation to a child other than one whom the foster parent is fostering.

Childcare provided by a relative

Qualifying childcare does not include care provided by a relative of the child in the child's own home. This includes relatives who are registered or approved childcare providers. For these purposes a relative means:

parent
step parent
foster parent
grandparent
aunt or uncle
brother or sister

whether by blood, half blood, marriage or civil partnership. In the case of foster parents this means a foster parent appointed by a local authority or voluntary organisation, or a person who fosters the child privately within the provisions of section 66 of the Children Act 1989.

Childcare provided by relatives can be qualifying childcare in the following circumstances

the relative is a 'registered' or 'approved' childcare provider, and
the care is provided away from the child's own home, and
the care is provided to non-related children in addition to the related child or children.