Child Support (Registration and Collection) Act 1988

Where judgment is given by, or entered in, a court for the payment of:

the whole or a part of a principal amount; or

an amount that includes the whole or a part of a principal amount;

the principal amount or the part of the principal amount, as the case may be, shall not be taken, for the purposes of subparagraph 51(b)(i), sub‑subparagraph 51(b)(ii)(B) or paragraph 52(a), as the case may be, to have ceased to be due and payable merely because of the giving or entering of the judgment; and

if the judgment debt carries interest, the amount that would, but for this paragraph, be payable under whichever of those provisions is applicable in relation to the principal amount or the part of the principal amount shall, by force of this paragraph, be reduced by:

in a case to which paragraph (a) applies—the amount of the interest; or

in a case to which paragraph (b) applies—an amount that bears the same proportion to the amount of the interest as the principal amount, or the part of the principal amount, bears to the amount of the judgment debt.

In subsection (1), principal amount means:

an amount of the kind referred to in section 51 as the principal amount;

an amount of the kind referred to in subparagraph 51(b)(ii) as the relevant penalty amount; or

an amount of the kind referred to in section 52 as the undeducted amount.