(1) If:
(a) any annual contribution payable by a person because of this Part remains unpaid after the time when it became due for payment; and
(b) the Internal Regulations of the 1992 Fund have fixed, or provided for a method of determining, one or more annual interest rates ( IR rates ) in accordance with paragraph 1 of Article 13 of the 1992 Convention;
the person is liable to pay, by way of penalty, an amount ( late payment penalty ). Late payment penalty is calculated at the annual percentage rate equal to whichever of the IR rates is applicable to the person's circumstances, on the amount unpaid, computed from that time.
(2) Late payment penalty is payable to the 1992 Fund on behalf of the Commonwealth.