18Amendment of assessments

18 Amendment of assessments

(1) Subject to this section, the Commissioner may, at any time within a period of 3 years after an assessment is made by him, amend the assessment by making such alterations or additions to it as he thinks necessary to correct an error in calculation or a mistake of fact or to prevent avoidance of tax. (2) Subsection (1) does not prevent the amendment of an assessment after the expiration of the period referred to in that subsection: (a) pending any appeal or review under Part V; (b) in order to give effect to the decision upon any appeal or review under that Part; (c) by way of reduction in pursuance of an objection made under that Part; or (d) where the person in respect of whom the assessment is made has not made to the Commissioner a full and true disclosure of all the material facts necessary for the assessment to be made and there has been an avoidance of tax. (2A) Where, by reason of an amendment of an assessment, a person’s liability to tax is reduced: (a) the amount by which the tax is so reduced shall be taken, for the purposes of section 36, never to have been payable; and (b) subject to subsection (3), the Commissioner shall: (i) refund the amount of any tax overpaid; or (ii) apply the amount of any tax overpaid against any liability of the person to the Commonwealth and refund any part of the amount that is not so applied. (3) Where by reason of an amendment under this section of an assessment made in pursuance of subsection 16(1) a financial institution has overpaid tax, the amount of the tax overpaid shall not be refunded to the financial institution or applied against a liability of the financial institution to the Commonwealth unless: (a) the amount of tax overpaid has not been recovered by the financial institution from an account holder; or (b) if the amount of tax overpaid has been recovered from an account holder and the Commissioner is satisfied that that amount has been or will be refunded to that account holder by the financial institution. (5) As soon as practicable after the amendment under this section of an assessment, the Commissioner shall cause notice in writing of the amended assessment and of the amount of tax payable in accordance with the amended assessment to be served, by post or otherwise, on the person in respect of whom the amended assessment is made. (6) An amended assessment is an assessment for all the purposes of this Act. (7) In this section, unless the contrary intention appears, tax includes additional tax under section 17 or 36.