(a) Installment payments. -- The estimated tax of a corporation with respect to which a declaration is required shall be paid as follows:

(1) If the declaration is filed on or before the fifteenth day of the fourth month of the taxable year, the estimated tax shall be paid in four equal installments. The first installment shall be paid at the time of the filing of the declaration, and the second, third and fourth installments shall be paid on the following fifteenth days of the sixth, ninth and twelfth months of the taxable year, respectively.

(2) If the declaration is filed after the fifteenth day of the fourth month and not after the fifteenth day of the sixth month of the taxable year, and is not required to be filed on or before the fifteenth day of the fourth month of the taxable year, the estimated tax shall be paid in three equal installments. The first installment shall be paid at the time of the filing of the declaration, and the second and third installments shall be paid on the following fifteenth days of the ninth and twelfth months of the taxable year, respectively.

(3) If the declaration is filed after the fifteenth day of the sixth month and not after the fifteenth day of the ninth month of the taxable year, and is not required to be filed on or before the fifteenth day of the sixth month of the taxable year, the estimated tax shall be paid in two equal installments. The first installment shall be paid at the time of the filing of the declaration, and the second shall be paid on the following fifteenth day of the twelfth month of the taxable year.

(4) If the declaration is filed after the fifteenth day of the ninth month of the taxable year, and is not required to be filed on or before the fifteenth day of the ninth month of the taxable year, the estimated tax shall be paid in full at the time of the filing of the declaration.

(5) If the declaration is filed after the time prescribed therefor, or after the expiration of any extension of time therefor, paragraphs (2), (3), and (4) of this subsection shall not apply, and there shall be paid at the time of such filing all installments of estimated tax payable at or before such time, and the remaining installments shall be paid at the times at which, and in the amounts in which, they would have been payable if the declaration had been filed when due.

(b) Amendments of declaration by any corporation. -- If any amendment of a declaration is filed by a corporation, the remaining installments, if any, shall be rateably increased or decreased (as the case may be) to reflect any increase or decrease in the estimated tax by reason of such amendment, and if any amendment is made after the fifteenth day of the ninth month of the taxable year, any increase in the estimated tax by reason thereof shall be paid at the time of making such amendment.

(c) Application to short taxable year. -- This section shall apply to a taxable year of less than twelve months in accordance with regulations of the Tax Commissioner.

(d) Installment paid in advance. -- Any corporation may elect to pay any installment of its estimated tax prior to the date prescribed for its payment.