Finality of assessment

—(1) Subject to the right of the Director General to issue a new or revised assessment under section 35, and subject to sub-section (2), if no request for review is made within the time permitted by section 38, an assessment is treated as final. (2) If an assessment is final under sub-section (1), and the taxpayer timely files an amended return under section 22, the filing of the amended return has the effect of revising the assessment, if the tax shown on the amended return exceeds the tax assessed.