(a)(1) Any company included in section 12-249, 12-256 or 12-264, or municipal utility, as defined in section 12-265, believing that it has overpaid any taxes due under the provisions of chapter 210, 211 or 212 may file a claim for refund in writing with the commissioner within three years from the due date for which such overpayment was made, stating the specific grounds upon which the claim is founded. Failure to file a claim within the time prescribed in this section constitutes a waiver of any demand against the state on account of overpayment. Not later than ninety days following receipt of such claim for refund, the commissioner shall determine whether such claim is valid and, if so, said commissioner shall notify the State Comptroller of the amount of such refund and the State Comptroller shall draw an order on the State Treasurer in the amount thereof for payment to such company or municipal utility. If the commissioner determines that such claim is not valid, either in whole or in part, he shall mail notice of the proposed disallowance in whole or in part of the claim to the claimant, which notice shall set forth briefly the commissioner's findings of fact and the basis of disallowance in each case decided in whole or in part adversely to the claimant. Sixty days after the date on which it is mailed, a notice of proposed disallowance shall constitute a final disallowance except only for such amounts as to which the taxpayer filed, as provided in subdivision (2) of this subsection, a written protest with the commissioner.

1. (2) On or before the sixtieth day after the mailing of the proposed disallowance, the company or municipal utility may file with the commissioner a written protest against the proposed disallowance in which it shall set forth the grounds on which the protest is based. If a protest is filed, the commissioner shall reconsider the proposed disallowance and, if the company or municipal utility has so requested, may grant or deny the company or municipal utility or its authorized representatives an oral hearing.
2. (3) The commissioner shall mail notice of his determination to the company or municipal utility, which notice shall set forth briefly the commissioner's findings of fact and the basis of decision in each case decided in whole or in part adversely to the company or municipal utility.
3. (4) The action of the commissioner on the company or municipal utility's protest shall be final upon the expiration of one month from the date on which he mails notice of his action to the company or municipal utility unless within such period the company or municipal utility seeks judicial review of the commissioner's determination pursuant to section 12-268l.

4. (b)

   1. (1) To any refunds granted as a result of overpayments of any taxes under chapter 210, 211 or 212, except refunds due because of any intentional overpayment, there shall be added interest at the rate of two-thirds of one per cent for each month or fraction of a month, as provided in subdivisions (2) and (3) of this subsection.
   2. (2) In case of such overpayment pursuant to a tax return, no interest shall be allowed or paid under this subsection on such overpayment for any month or fraction thereof prior to (A) the ninety-first day after the last day prescribed for filing the tax return associated with such overpayment, or (B) the ninety-first day after the date such return was filed, whichever is later.
   3. (3) In case of such overpayment pursuant to an amended tax return, no interest shall be allowed or paid under this subsection on such overpayment for any month or fraction thereof prior to the ninety-first day after the date such amended tax return was filed.

(1961, P.A. 604, S. 18; P.A. 77-614, S. 139, 610; P.A. 87-124, S. 6, 18; P.A. 89-343, S. 3, 17; P.A. 93-361, S. 5; P.A. 95-26, S. 5, 52; P.A. 97-243, S. 54, 67; P.A. 06-186, S. 72; P.A. 13-232, S. 1.)

History: P.A. 77-614 substituted commissioner of revenue services for tax commissioner, effective January 1, 1979; P.A. 87-124 inserted reference to chapter 210 concerning taxation of railroad companies, effective January 1, 1988, and applicable with respect to tax imposed under chapter 210 on gross earnings in the calendar year ending December 31, 1987, and in each calendar year thereafter; P.A. 89-343 increased the rate of interest from 0.5% to 0.75% per month or fraction thereof; P.A. 93-361 made existing section Subsec. (b) and inserted a new Subsec. (a) providing for claims for refund of taxes upon overpayment; P.A. 95-26 amended Subsec. (b) to lower interest rate from 0.75% to 0.66%, effective July 1, 1995, and applicable to taxes due and owing on or after July 1, 1995, whether or not those taxes first became due before said date; P.A. 97-243 amended Subsec. (a) to provide for an administrative hearing with the department before taking an appeal to the Superior Court, to establish the time for filing a claim and to provide that failure to file within the time prescribed constitutes a waiver of any demand against the state on account of overpayment, and made technical changes, effective July 1, 1997, and applicable to claims for refund filed on or after said date; P.A. 06-186 amended Subsec. (a)(1) by adding citation to Sec. 12-265 re definition of municipal utility, effective July 1, 2006; P.A. 13-232 amended Subsec. (b) by designating existing provisions re refunds granted as result of overpayments as new Subdiv. (1) and deleting former Subdivs. (1) and (2) and making a conforming change therein, and adding new Subdivs. (2) and (3) re timing of interest payment, effective July 1, 2013, and applicable to refunds issued on or after that date.