(a) Except as otherwise provided in this section, in the case of any underpayment of estimated tax by a company, there shall be added to the tax under this chapter for the calendar year an amount determined by applying (1) interest at the rate of one per cent per month or portion thereof, (2) to the amount of the underpayment, (3) for the period of the underpayment.

Terms Used In Connecticut General Statutes 12-204c

(b) For purposes of subsection (a) of this section, the amount of the underpayment shall be the excess of the required installment, over the amount, if any, of the installment paid on or before the due date for the installment. For purposes of subsection (a) of this section, the period of the underpayment shall run from the due date for the installment to whichever of the following dates is the earlier; the first day of the third month following the close of the calendar year, or, with respect to any portion of the underpayment, the date on which such portion is paid. For purposes of this subsection, a payment of estimated tax shall be credited against unpaid required installments in the order in which such installments are required to be paid.

(c) For purposes of this section, there shall be four required installments for each calendar year. The due date for the first required installment is the fifteenth day of the third month of the calendar year. The due date for the second required installment is the fifteenth day of the sixth month of the calendar year. The due date for the third required installment is the fifteenth day of the ninth month of the calendar year. The due date for the fourth required installment is the fifteenth day of the twelfth month of the calendar year.

(d) (1) The amount of the first required installment shall be thirty per cent of the required annual payment, as defined in subdivision (2) of this subsection. The amount of the second required installment shall be thirty per cent of the required annual payment, as defined in subdivision (2) of this subsection. The amount of the third required installment shall be twenty per cent of the required annual payment, as defined in subdivision (2) of this subsection. The amount of the fourth required installment shall be twenty per cent of the required annual payment, as defined in subdivision (2) of this subsection.

(2) The required annual payment means the lesser of: (A) Ninety per cent of the tax shown on the return for the calendar year or, if no return is filed, ninety per cent of the tax for such year, or (B) one hundred per cent of the tax shown on the return for the preceding calendar year. Subparagraph (B) of this subdivision shall not apply if the company did not file a return for such preceding calendar year showing a liability for tax.

(e) No addition to tax shall be imposed under subsection (a) of this section for any calendar year if the tax shown on the return for such calendar year or, if no return is filed, the tax for such calendar year, is less than one thousand dollars.

(f) The application of this section to calendar years of less than twelve months shall be in accordance with regulations adopted by the commissioner.

(g) At the election of the company, an installment of the estimated tax may be paid prior to the date prescribed for its payment.

(h) Payment of the estimated premium tax, or any installment thereof, shall be considered payment on account of the premium tax imposed under this chapter for the income year.