This states “140A. (1) Where a return has been furnished under section 139 and the tax payable on the basis of that return as reduced by any tax already paid under any provision of this Act exceeds five hundred rupees, the assessee shall pay the tax so payable within thirty days of furnishing the return.
2. After a provisional assessment under section 141 or a regular assessment under section 143 or section 144 has been made, any amount paid under sub-section (1) shall be deemed to have been paid towards the provisional assessment or regular assessment, as the case may be.
3. If any assessee fails to pay the tax or any part thereof in accordance with the provisions of sub-section (1),he shall, unless a provisional assessment under section 141 or a regular assessment under section 143 or section 144 has been made before the expiry of thirty days referred to in that sub-section, be liable, by way of penalty, to pay such amount as the Income- tax Officer may direct, so however, that the amount of penalty does not exceed fifty per cent, of the amount of such tax or part, as the case may be :
Provided that before levying any such penalty, the assessee shall be given a reasonable opportunity of being heard” The assessee calculates the income tax to be paid on his own. The tax department has different forms to be filed for income tax return. The assessee affiliates the self earned income through multiple sources and fits the same against different loss or deductions or other exemptions if there are any left during the year and the total income of the assessee is assessed. Then, the assessee subtracts the TDS and Advance Tax from that amount to determine the tax payable on such income. If the tax is still payable, then it is called as the self assessment tax and must be paid before the person files the return of income. This procedure is said to be Self Assessment.