N.Y. Yonkers Income Tax Surcharge Law § 15-129
If the amount of a taxpayer's federal or New York State taxable income or self-employment income reported on his/her federal or New York State Tax return for any taxable year is changed or corrected by the United States Internal Revenue Service or the New York State Tax Commission or other competent authority, or as the result of a renegotiation of a contract or subcontract with the United States or New York State or if a taxpayer, pursuant to Subsection (d) of Section 6213 of the Internal Revenue Code, executing a notice of waiver of the restrictions provided in Subsection (a) of said section, or if a taxpayer, pursuant to § 681, Subdivision (f), of the New York State Tax Law executes a notice of waiver of the restrictions provided in Subdivision (c) of said section, or if any tax on self-employment income in addition to that shown on his/her return is assessed, the taxpayer shall report such change or correction in federal or New York State taxable income or such execution of such notice of waiver or such assessment and the changes or corrections of his/her federal or New York State taxable income or self-employment income on which it is based, within ninety (90) days after the final determination of such change, correction or renegotiation or such execution of such notice of waiver or the making of such assessment as otherwise required by the State Tax Commission and shall concede the accuracy of such determination or state wherein it is erroneous. Any taxpayer filing an amended federal or New York State income or self-employment income tax return shall also file within ninety (90) days thereafter an amended return under this article and shall give such information as the State Tax Commission may require. The State Tax Commission may, by regulation, prescribe such exceptions to the requirements of this section as it deems appropriate.
N.Y. Yonkers Income Tax Surcharge § 15-129