N.Y. GCT Law § 66

§ 66. Overpayment.--(a) General.--The administrator, within the\napplicable period of limitations, may credit an overpayment of income\ntax and interest on such overpayment against any liability in respect of\nany tax imposed by this local law or by any local law of the city which\nimposes an unincorporated business income tax on the person who made the\noverpayment, and the balance shall be refunded. Any refund under this\nsection shall be made only upon the filing of a return.\n (b) Excessive withholding.--If the amount allowable as a credit for\ntax withheld from the taxpayer exceeds his tax to which the credit\nrelates, the excess shall be considered an overpayment.\n (c) Overpayment by employer.-- If there has been an overpayment of tax\nrequired to be deducted and withheld under section fifty-one, refund\nshall be made to the employer only to the extent that the amount of the\noverpayment was not deducted and withheld by the employer.\n (d) Credits against estimated tax.--The administrator may prescribe\nregulations providing for the crediting against the estimated income tax\nfor any taxable year of the amount determined to be an overpayment of\nthe income tax for a preceding taxable year. If any overpayment of\nincome tax is so claimed as a credit against estimated tax for the\nsucceeding taxable year, such amount shall be considered as a payment of\nthe income tax for the succeeding taxable year (whether or not claimed\nas a credit in the declaration of estimated tax for such succeeding\ntaxable year), and no claim for credit or refund of such overpayment\nshall be allowed for the taxable year for which the overpayment arises.\n (e) Rule where no tax liability.--If there is no tax liability for a\nperiod in respect of which an amount is paid as income tax, such amount\nshall be considered an overpayment.\n (f) Assessment and collection after limitation period.--If any amount\nof income tax is assessed or collected after the expiration of the\nperiod of limitations properly applicable thereto, such amount shall be\nconsidered an overpayment.\n