Commonwealth Consolidated Acts(1) If:
(a) an amount is paid or applied towards discharging a liability to pay an estimate; and
(b) the amount exceeds the unpaid amount of the underlying liability as at the time ( the liability time ) immediately before the payment or application;
the Commissioner must either refund the excess or:
(c) apply the excess against any liability of the person to the Commonwealth that arises under or because of an Act of which the Commissioner has the general administration; and
(d) refund so much of the excess as is not applied under paragraph (c).
(2) If the Commissioner refunds or applies an amount under subsection (1), he or she must also reduce the amount of the estimate by the amount by which the unpaid amount of the estimate as at the liability time exceeded the unpaid amount of the underlying liability at that time.