N.Y. Comp. Codes R. & Regs. tit. 20 § 269.1
Tax Law, § 7 of § 1340(c); Codes and Ordinances of the City of Yonkers, § 92-104
Every employer maintaining an office or transacting business in New York State, and making payment of any wages subject to the City of Yonkers earnings tax on nonresidents imposed by article X of the Codes and Ordinances of the City of Yonkers, must deduct and withhold such earnings tax from such wages in accordance with the provisions of Article 5 of Subchapter A of this Chapter (see Parts 171 through 178 of this Title). Such Article 5 of Subchapter A of this Chapter shall be applicable to the administration by the State Tax Commission of the requirement of withholding the earnings tax imposed by such article X of the Codes and Ordinances of the City of Yonkers from wages subject to such earnings tax in the same manner and with the same force and effect as if such Article 5 of Subchapter A of this Chapter had been incorporated in full in this Subchapter, and as if such Article 5 of Subchapter A of this Chapter had specifically referred to the requirement of withholding the City of Yonkers earnings tax on nonresidents by employers from wages subject to such earnings tax, except where inconsistent with or not relevant to the provisions of this Subchapter, article 30-B of the Tax Law or article X of the Codes and Ordinances of the City of Yonkers or otherwise expressly provided for in this Subchapter.
N.Y. Comp. Codes R. & Regs. Tit. 20 § 269.1