N.Y. Comp. Codes R. & Regs. tit. 20 § 251.2
Tax Law, § 1329; Codes and Ordinances of the City of Yonkers, § 92-88
Every employer required to deduct and withhold City of Yonkers income tax surcharge on residents, pursuant to section 1329 of the Tax Law and section 92-88 of the Codes and Ordinances of the City of Yonkers, shall file an employer's return and with such return pay over to the Department of Taxation and Finance the amount of the City of Yonkers income tax surcharge so required to be deducted and withheld. An employer's return of City of Yonkers income tax surcharge withheld must be filed in the same manner as is provided for in Part 174 of this Title. However, in determining the threshold for filing such employer' s return and making payment of City of Yonkers income tax surcharge withheld, the amount of City of Yonkers income tax surcharge required to be deducted and withheld shall be aggregated with the amounts of New York State personal income tax, City of New York personal income tax on residents, City of New York earnings tax on nonresidents and City of Yonkers earnings tax on nonresidents required to be deducted and withheld, and the total of all such withheld amounts determines the manner and timing of filing such employer's returns and making payment of such withheld amounts.
N.Y. Comp. Codes R. & Regs. Tit. 20 § 251.2