(1)In any case where—
(a)any benefit as defined in section 122 of the Contributions and Benefits Act or any increase of such benefit (“the relevant benefit or increase”) has been paid to a person for a period in respect of a child; and
(b)subsequently child benefit for that period in respect of the child becomes payable at a rate which is such that, had the relevant benefit or increase been awarded after the child benefit became payable, the rate of the relevant benefit or increase would have been reduced,
then, except in so far as regulations otherwise provide, the excess shall be treated as paid on account of child benefit for that period in respect of the child.
(2)In subsection (1) above “the excess” means so much of the relevant benefit or increase as is equal to the difference between—
(a)the amount of it which was paid for the period referred to in that subsection; and
(b)the amount of it which would have been paid for that period if it had been paid at the reduced rate referred to in paragraph (b) of that subsection.