(1) An enforcement agency or the Secretary (as the case requires) must allocate money received under a payment plan in order of priority based on the date each infringement notice was issued in respect of the infringement penalty and any prescribed costs under the payment plan, with the infringement penalty and any prescribed costs under the oldest notice being paid out first.
(2) The order of priority to be applied when payments under a payment plan are allocated applies—
(a) to all payment plans managed by the Secretary or by an enforcement agency; and
(b) in the case of payment plans managed by the Secretary, regardless of the origin of the infringement penalty and any prescribed costs under the payment plan.
(3) If a person to whom a payment plan applies makes an overpayment by continuing payments after the payment plan is completed, the Secretary or an enforcement agency (as the case requires) must advise the person to whom the plan applies of the overpayment and may—
(a) if the person has other outstanding infringement penalties and any prescribed costs in respect of an infringement offence or outstanding enforcement orders in respect of a lodgeable infringement offence, offer to apply the amount of the overpayment to those outstanding infringement penalties and prescribed costs or any outstanding enforcement orders (as the case requires) if the person—
(i) consents to the amount being so applied; and
(ii) directs the agency or Secretary to do so; or
(b) refund the amount of the overpayment to the person and—
(i) if the amount had been paid into the Consolidated Fund, the Consolidated Fund is, to the necessary extent, appropriated accordingly; or
(ii) if the amount had been paid into another fund or account, the amount is to be refunded from that fund or account.