53.4961-2—Court proceedings to determine liability for second tier tax.

(3) Refund proceeding commenced before correction period ends. A proceeding is described in this subparagraph (3) if it is a proceeding commenced under section 7422, in accordance with the provisions of § 53.4963-1(e) (4) and (5) (relating to prerequisites to extension of the correction period during certain refund proceedings), and with respect to the taxpayer's liability for second tier tax.
(d) Restriction on assessment during Tax Court proceeding. If a supplemental proceeding described in section 4961 (b) and § 53.4961-2(c) is commenced in the Tax Court, the provisions of the second and third sentences of section 6213(a) and the first and third sentences of § 301.6213-1(a)(2) apply with respect to a deficiency in second tier tax until the decision of the Tax Court in the supplemental proceeding is final.
(2) Refund proceeding. For purposes of this subpart K, § 301.7422-1 applies in determining when a decision in a refund proceeding becomes final.