26 U.S.C. § 6232: Assessment, collection, and payment

subchapter B of chapter 63 shall not apply, and in the case of an administrative adjustment request to which section 6227(b)(1) applies, the underpayment shall be paid and may be assessed when the request is filed. the close of the 90th day after the day on which a notice of a final partnership adjustment was mailed, and if a petition is filed under section 6234 with respect to such notice, the decision of the court has become final. Notwithstanding section 7421(a), any action which violates subsection (b) may be enjoined in the proper court, including the Tax Court. The Tax Court shall have no jurisdiction to enjoin any action under this subsection unless a timely petition has been filed under section 6234 and then only in respect of the adjustments that are the subject of such petition. If the partnership is notified that, on account of a mathematical or clerical error appearing on the partnership return, an adjustment to an item is required, rules similar to the rules of paragraphs (1) and (2) of section 6213(b) shall apply to such adjustment. If a partnership is a partner in another partnership, any adjustment on account of such partnership’s failure to comply with the requirements of section 6222(a) with respect to its interest in such other partnership shall be treated as an adjustment referred to in subparagraph (A), except that paragraph (2) of section 6213(b) shall not apply to such adjustment. The partnership may at any time (whether or not any notice of partnership adjustment has been issued), by a signed notice in writing filed with the Secretary, waive the restrictions provided in subsection (b) on the making of any partnership adjustment. If no proceeding under section 6234 is begun with respect to any notice of a final partnership adjustment during the 90-day period described in subsection (b), the amount for which the partnership is liable under section 6225 shall not exceed the amount determined in accordance with such notice. section 6621(a)(2)(B) shall be applied by substituting “5 percentage points” for “3 percentage points” with respect to such amount, and the Secretary may assess upon each partner of the partnership (determined as of the close of the adjustment year or, if the partnership has ceased to exist as of such time, the former partners of the partnership as determined for purposes of section 6241(7)) a tax equal to such partner’s proportionate share of such amount (including any such interest or penalties, determined after application of subparagraph (A)). the amount described in subclause (II) of section 6226(b)(4)(A)(ii) (including any failure to satisfy the requirement of subclause (I) of such section which is treated as a failure to pay such amount under section 6651(i)), and any amount assessed under paragraph (1)(B) upon a partner which is a partnership. For purposes of paragraph (1), a partner’s proportionate share is such percentage as the Secretary may determine on the basis of such partner’s distributive share. The Secretary shall make determinations under the preceding sentence such that the aggregate proportionate shares so determined total 100 percent. The liability of the partnership for any amount with respect to which a partner is made liable under paragraph (1) shall be reduced upon payment by the partner of such amount. Paragraph (1)(B) shall not apply with respect to any amount after the date on which such amount is paid by the partnership. For purposes of this subsection, an S corporation and its shareholders shall be treated in the same manner as a partnership and its partners. Subchapter B shall not apply to any assessment or collection under this paragraph. Except as otherwise provided in this subtitle, no assessment may be made (or proceeding in court begun without assessment) with respect to any partner with respect to an amount under paragraph (1) after the date which is 2 years after the date on which the Secretary provides the notice and demand referred to in paragraph (1) with respect to such amount.