Section 806.1 - Interest on overpayments(a) "Overpayment" shall mean any payment of tax which is determined in the manner provided by law not to be legally due. Simple interest shall be allowed and paid by the Commonwealth upon any overpayment to the Commonwealth of any tax. The interest shall be allowed and paid for the period during which the Commonwealth retained the overpayment, beginning with the date of the overpayment, except that: (1) Any tax actually deducted and withheld at the source shall be deemed to have been overpaid on the last day prescribed for filing the return or report for the taxable year (determined without regard to any extension of time for filing).(2) Any amount overpaid as estimated tax, tentative tax or installment payment for a taxable year shall be deemed to have been overpaid on the last day prescribed for filing the final return or report for the taxable year (determined without regard to any extension of time for filing).(3) Any overpayment made before the last day prescribed for payment shall be considered made on the last day.(4) Any amount claimed to be overpaid with respect to which an administrative review or appellate procedure is initiated in the manner provided by law by the taxpayer shall be deemed to have been overpaid sixty (60) days following the date of initiation of said review or procedure.(5) If any overpayment of tax is refunded or credited within seventy-five (75) days after the last date prescribed for filing the final return or report of the tax (determined without regard to any extension of time for filing) or, in case the final return or report is filed after the last day, and is refunded or credited within seventy-five (75) days after the date the final return or report is filed, no interest shall be allowed on the overpayment. For the purpose of this clause, a final return or report shall be deemed to have been filed only if, when it is received by the Department of Revenue, it has been submitted on a permitted form containing (i) the taxpayer's name, address and identifying number and the required signature; and (ii) sufficient required information, either on the permitted form or attachments thereto, to permit the verification of tax liability shown on the return.(6) Any tax paid to an officer, licensee or collector shall be deemed to have been overpaid no earlier than the first date that the tax is required by law to be reported and transmitted to the department by the officer, licensee or collector.(7) No overpayment of interest or penalty shall bear any interest whatsoever.(b) Interest on overpayments shall be allowed and paid at the rate as is prescribed for underpayments under section 806 less two per centum.(b.1) Interest on overpayments of the tax imposed under Article III of the act of March 4, 1971 (P.L. 6, No. 2), known as the "Tax Reform Code of 1971," shall be allowed and paid at the same rate as is prescribed for underpayments undersection 806.(c) Interest on overpayments shall be allowed and paid as follows:(1) In the case of a cash refund, from the date of the overpayment to a date preceding the date of the Commonwealth's refund check by not more than thirty (30) days.(2) In the case of a credit for an overpayment, from the date of the overpayment to: (i) The date of the Commonwealth's notice to the taxpayer of the final determination of the credit; or(ii) The date as of which the credit is applied, whichever first occurs: Provided, however, That in the case of a cash refund of a previously determined credit, interest shall be allowed and paid on the amount of the credit from a date ninety (90) days after the filing of a petition for a cash refund to a date preceding the date of the refund check by not more than thirty (30) days whether or not the refund check is accepted by the taxpayer after tender to the taxpayer.(3) The taxpayer's acceptance of the Commonwealth's check shall be without prejudice to any right of the taxpayer to claim any additional overpayment and interest thereon. Tender of a refund check shall be deemed acceptance thereof for the purposes of this section.1929, April 9, P.L. 343, § 806.1, added 1982, April 8, P.L. 258, No. 78, § 2, imd. effective. Amended 1982, Dec. 9, P.L. 1057, No. 248, § 3, imd. effective; 1986, July 18, P.L. 1411, No. 127, § 1, effective in 60 days; 2003, Dec. 23, P.L. 243, No. 45, § 2, effective 2/23/2004.