Section 5866 - Supplemental information; changes in federal tax liability or taxable income(a) If, after the time for filing any return required by this chapter, a taxpayer:(1) becomes aware of any information that makes that return materially false, inaccurate, or incomplete;(2) is notified of any assertion by the United States, whether under 26 U.S.C. § 6212 or otherwise, that the taxpayer's taxable income under the laws of the United States is other than the amount stated in the return; or(3) files an amended return under the laws of the United States, the taxpayer shall, within 180 days of the receipt of that information or notification of that assertion or filing that amended return, notify the Commissioner thereof, and of such particulars as may be relevant to the amount of any tax liability of the taxpayer under this chapter.(b) Any notice required to be given to the Commissioner under this section shall be considered to be a return for purposes of this chapter, and a taxpayer required to file any such return shall be subject, with respect thereto, to the provisions of this chapter, including the provisions governing fees for failure to file a return, except as those provisions conflict with the express provisions of this section.(c) If a change in federal tax liability results from the audit of a partnership or an adjustment of a partnership's taxable income under 26 U.S.C. subtitle F, chapter 63, subchapter C, the taxpayer shall file and amend returns and pay tax owed pursuant to section 5866a of this title.Amended by 2022 , No. 179, § 12, eff. 1/1/2022, app. to any adjustments to a taxpayer's federal taxable income with a final determination date occurring on and after July 1, 2022.Amended by 2022 , No. 105, § 539, eff. 7/1/2022.Added 1966, No. 61 (Sp. Sess.), § 1, eff. 1/1/1966; amended 2005, No. 94 (Adj. Sess.), § 4, eff. 3/8/2006; 2019, No. 175 (Adj. Sess.), § 17, eff. 10/8/2020.