(1) The Commissioner may, subject to this section, at any time amend any assessment by making any alterations or additions that the Commissioner thinks necessary, whether or not superannuation guarantee charge has been paid in relation to the assessment.
(2) Subject to this section, if there has been an avoidance of superannuation guarantee charge, the Commissioner may:
(a) if the Commissioner is of the opinion that the avoidance of the charge is due to fraud or evasion--at any time; or
(b) in any other case--within 4 years from the day on which the assessment is made;
amend the assessment by making any alterations or additions that the Commissioner thinks necessary to correct the assessment.
(3) An amendment effecting a reduction in an employer's liability under an assessment is not effective unless it is made within 4 years from the day on which the assessment was made.
(4) If an assessment has, under this section, been amended in any particular, the Commissioner may, within 4 years from the day on which superannuation guarantee charge became payable under the amended assessment, make, in or in relation to the particular, any further amendment in the assessment that, in the Commissioner's opinion, is necessary to effect such reduction in the employer's liability under the assessment as is just.
(a) an employer applies for an amendment of the employer's assessment within 4 years from the day that superannuation guarantee charge became payable under the assessment; and
(b) within that period, the employer lodges all information the Commissioner needs to decide the application;
the Commissioner may amend the assessment when considering the application, even if that period has elapsed.
(6) Nothing in this section prevents the amendment of an assessment to give effect to:
(a) the decision on any review or appeal; or
(b) its amendment by reduction of any particular following the employer's objection or pending any review or appeal.
(7) Superannuation guarantee charge under an amended assessment is taken to have become payable on the day on which charge under the original assessment became payable.