(1) The Commissioner may make 1 or more reassessments of a tax liability of a taxpayer.
(2) A reassessment of a tax liability shall be made in accordance with the legal interpretations and assessment practices generally applied by the Commissioner in relation to matters of that kind at the time the tax liability arose except to the extent that any departure from those interpretations and practices is required by a change in the law (whether legislative or non-legislative) made after that time.
(3) The Commissioner shall not make a reassessment of a tax liability more than 5 years after the initial assessment of the liability, unless—
(a) the purpose of the reassessment is to give effect to a decision on an objection or appeal as to the initial assessment; or
(b) at the time the initial assessment or a reassessment was made, all the facts and circumstances affecting the liability under the relevant tax law of the person in respect of whom the assessment or reassessment was made were not fully and truly disclosed to the Commissioner.
(4) The initial assessment of a tax liability remains the initial assessment of the liability for the purposes of this Act even if it is withdrawn under section 13.