26 U.S.C. § 6512: Limitations in case of petition to Tax Court

As to overpayments determined by a decision of the Tax Court which has become final, and As to any amount collected in excess of an amount computed in accordance with the decision of the Tax Court which has become final, and As to any amount collected after the period of limitation upon the making of levy or beginning a proceeding in court for collection has expired; but in any such claim for credit or refund or in any such suit for refund the decision of the Tax Court which has become final, as to whether such period has expired before the notice of deficiency was mailed, shall be conclusive, and As to overpayments attributable to partnership items, in accordance with subchapter C of chapter 63, and As to any amount collected within the period during which the Secretary is prohibited from making the assessment or from collecting by levy or through a proceeding in court under the provisions of section 6213(a), and As to overpayments the Secretary is authorized to refund or credit pending appeal as provided in subsection (b). Except as provided by paragraph (3) and by section 7463, if the Tax Court finds that there is no deficiency and further finds that the taxpayer has made an overpayment of income tax for the same taxable year, of gift tax for the same calendar year or calendar quarter, of estate tax in respect of the taxable estate of the same decedent, or of tax imposed by chapter 41, 42, 43, or 44 with respect to any act (or failure to act) to which such petition relates, in respect of which the Secretary determined the deficiency, or finds that there is a deficiency but that the taxpayer has made an overpayment of such tax, the Tax Court shall have jurisdiction to determine the amount of such overpayment, and such amount shall, when the decision of the Tax Court has become final, be credited or refunded to the taxpayer. If a notice of appeal in respect of the decision of the Tax Court is filed under section 7483, the Secretary is authorized to refund or credit the overpayment determined by the Tax Court to the extent the overpayment is not contested on appeal. If, after 120 days after a decision of the Tax Court has become final, the Secretary has failed to refund the overpayment determined by the Tax Court, together with the interest thereon as provided in subchapter B of chapter 67, then the Tax Court, upon motion by the taxpayer, shall have jurisdiction to order the refund of such overpayment and interest. An order of the Tax Court disposing of a motion under this paragraph shall be reviewable in the same manner as a decision of the Tax Court, but only with respect to the matters determined in such order. after the mailing of the notice of deficiency, within the period which would be applicable under section 6511(b)(2), (c), or (d), if on the date of the mailing of the notice of deficiency a claim had been filed (whether or not filed) stating the grounds upon which the Tax Court finds that there is an overpayment, or which had not been disallowed before that date, which had been disallowed before that date and in respect of which a timely suit for refund could have been commenced as of that date, or in respect of which a suit for refund had been commenced before that date and within the period specified in section 6532. The Tax Court shall have no jurisdiction under this subsection to restrain or review any credit or reduction made by the Secretary under section 6402. For provisions allowing determination of tax in title 11 cases, see section 505(a) of title 11 of the United States Code. For provision giving the Tax Court jurisdiction to award reasonable litigation costs in proceedings to enforce an overpayment determined by such court, see section 7430.