(1) Every person who is required to file a return under section 166, 172, 175, 191, 193 or 212 shall pay the tax payable on or before the date of filing of the return.

(2) The tax payable shall be computed as per the formula A-B, where—

A = tax payable by the assessee on the basis of the return or under the provisions of sub-section (5) of section 163, whichever is higher;

B = tax paid at source or advance tax in accordance with the provisions of Part 7.

(3) The amount paid under sub-section (1) shall be deemed to have been paid as tax payable by the assessee after regular assessment.

(4) If any person, without reasonable cause, fails to pay the tax payable under sub-section (1), he shall be deemed to be an assessee-in-default.