(1) The tax assessed or any other amount demanded under this Act shall be paid in such manner and within such time not being less than fifteen days from the date of the notice of demand as may be specified in the notice. In default of such payment the whole of the amount then remaining due shall become recoverable in accordance with sections 16 and 16-A.

Provided that the Commissioner or any other officer not below the rank of assessing authority, authorized in writing by the Commissioner, may on an application in the prescribed form extend, the date of payment specified in the notice of demand or allow him to pay demand in instalments subject to such conditions including the payment of interest under sub section (2) and furnishing of a security, as the officer may consider necessary.

(2) If the tax or any other amount due under this Act excluding interest is not paid by the dealer or any other person, by whom it is payable within the period allowed, the dealer or such other person shall be liable to pay interest on the tax or other amount from the date it was payable to the date of actual payment at the rate of 2 per cent per month;

Provided that where as a result of an order under sections 11, 11-A, 12, 24 or an order of the court the amount of tax or other sum on which interest was payable under this sub section has been reduced the interest shall be reduced accordingly and excess interest paid, if any, shall be refunded.

(3) Quarterly tax shall be paid before furnishing a quarterly return but not later than the date prescribed under sub section (2) of section 7.

(4) Notwithstanding anything contained in sub section (3) if the Assessing Authority extends the date for furnishing quarterly return under sub section (5) of section 7, an amount equal to the amount of quarterly tax payable or paid for the immediately preceding quarter shall be paid before the prescribed date in lieu of quarterly tax;

Provided that a dealer who was not previously liable to pay any quarterly tax shall make an estimate of the tax payable for the quarter and deposit the same before the prescribed date.

(5) Where any dealer fails to furnish any quarterly return and fails to pay the tax in accordance with sub section (4) an amount equal to the amount of tax payable or paid for the immediately preceding quarter shall become payable towards the tax payable for the said quarter.

(6) The tax paid under sub section (4) and (5) shall be treated to be quarterly tax payable under sub section (3) and shall be adjusted towards the tax payable for the quarter in respect of which it is paid;

Provided that the difference between the tax payable on the basis of quarterly return and the tax paid under the aforesaid sub sections shall be paid before the date to which the period of furnishing the return has been extended or date of furnishing the return, whichever is earlier.

Provided further if the amount already paid is in excess of the quarterly tax payable, the excess thereof shall be refunded, and if the assessee so desires, the said amount of refund shall be treated to have been paid towards the tax payable for the next following quarter and the assessee shall be entitled to interest on the amount of such refund in accordance with the provisions of section 10-B of the Act.

(7) Where a dealer furnishes a revised return under sub section (4) of section and the tax payable is more than the tax paid on the basis of original return he shall pay the extra tax payable before furnishing the revised returns.

Provided that if the tax already paid is in excess of the tax payable, such excess amount shall be treated to have been paid towards the tax payable for the quarter next following the date of furnishing such revised return.

(8) Notwithstanding anything contained in this Act, but subject to the provisions of sub section (5) of section 16-C of this Act, if a dealer fails to pay the quarterly tax under this section he shall be liable to pay interest on the tax from the date it was payable to the date of actual payment at the rates prescribed in sub section (2) of this section and the provisions of section 16 and section 16-A shall apply mutatis mutandis to the recovery thereof.

Explanation 1 Quarterly tax means the tax payable on the basis of a quarterly return required to be furnished under sub section (2) of section 7 or the tax determined for a quarter.

Explanation 2 Interest under sub section (2) of this section on the extra tax payable on the basis of revised return, shall be payable from the date next following the date on which the tax was payable on the basis of original return.

Explanation 3 For purposes of sub section (2) and sub section (8) of this section interest payable for part of the month shall be proportionately determined according to the number of days of default.