4.—(1) Whether a person is responsible for a child or qualifying young person for the purposes of Part 1 of the Act and these Regulations is determined as follows.
(2) A person is responsible for a child or qualifying young person who normally lives with them.
(3) But a person is not responsible for a qualifying young person if the two of them are living as a couple.
(4) Where a child or qualifying young person normally lives with two or more persons who are not a couple, only one of them is to be treated as responsible and that is the person who has the main responsibility.
(5) The persons mentioned in paragraph (4) may jointly nominate which of them has the main responsibility but the Secretary of State may determine that question—
(a)in default of agreement; or
(b)if a nomination or change of nomination does not, in the opinion of the Secretary of State, reflect the arrangements between those persons.
(6) A child or qualifying young person is to be treated as not being the responsibility of any person during any period when the child or qualifying young person is—
(a)looked after by a local authority; or
(b)a prisoner,
but there is excluded from sub-paragraph (a) any period which is in the nature of a planned short term break, or is one of a series of such breaks, for the purpose of providing respite for the person who normally cares for the child or qualifying young person.
(7) Where a child or qualifying young person is temporarily absent from a person’s household the person ceases to be responsible for the child or qualifying young person if—
(a)the absence is expected to exceed, or does exceed, 6 months; or
(b)the absence is from Great Britain and is expected to exceed, or does exceed, one month unless it is in circumstances where an absence of a person for longer than one month would be disregarded for the purposes of regulation 11(2) or (3) (medical treatment or convalescence or death of close relative etc.).