PETROLEUM RESOURCE RENT TAX ASSESSMENT ACT 1987
If, because of an amendment of an assessment, a person's liability (the earlier liability ) to tax or a related charge is reduced, the amount by which the tax or charge is so reduced is taken never to have been payable for the purposes of:
(a) section 85 (which applies the general interest charge); and
(b) Division 280 in Schedule 1 tot he Taxation Administration Act 1953 (which applies the shortfall interest charge).
The general interest charge is worked out under Division 1 of Part IIA of the Taxation Administration Act 1953 .72(2)
The Commissioner must refund or apply the amount of any tax overpaid in accordance with Divisions 3 and 3A of Part IIB of the Taxation Administration Act 1953 . 72(3)
However, if a later amendment of the assessment is made and all or some of the person's earlier liability in relation to a particular is reinstated, subsection (1) is taken not to have applied, or not to have applied to the extent that the earlier liability is reinstated.
If the amendment of an assessment results in an increase in a person's tax liability, the person is liable to pay shortfall interest charge on the amount of the increase: see Division 280 in Schedule 1 to the Taxation Administration Act 1953 .