11.—(1) For the purposes of section 143(5)(a) of SSCBA and section 139(5)(a) of SSCB(NI)A (contributing to the cost of providing for a child or qualifying young person) the prescribed circumstances are that—
(a)two or more persons are contributing to the cost of providing for the same child or qualifying young person;
(b)the aggregate weekly amount of their contributions equals or exceeds, but the weekly amount of each of their individual contributions is less than, the weekly rate of child benefit which would be payable in respect of that child or qualifying young person had the aggregate weekly amount of their contributions been contributed by one only of them; and
(c)they by agreement nominate in writing or, in default of such agreement, the Commissioners in their discretion determine, that the aggregate weekly amount of their contributions is to be treated as having been made by the person so nominated or determined.
This paragraph is subject to paragraph (3).
(2) The contribution subject to the nomination or determination made under paragraph (1) shall be treated as made by the person nominated or determined.
(3) Where pursuant to a nomination or determination made under paragraph (1) a person is awarded child benefit, the nomination or determination ceases to have effect in the week following that in which child benefit is awarded to that person (and accordingly thereafter the person shall be required to contribute to the maintenance of the child or qualifying young person at a rate which equals or exceeds the rate of child benefit payable in respect of that child or qualifying young person).
(4) Where spouses or civil partners are residing together a contribution made or expenditure incurred by one of them in respect of a child or qualifying young person shall if they agree, or in default of such agreement if the Commissioners in their discretion so determine, be treated as made or incurred by the other.