N.Y. Comp. Codes R. & Regs. tit. 20 § 2393.1
Overpayment and underpayment rates of interest. Except as otherwise provided by law, interest rates used in computing the amounts of interest to be paid on overpayments or imposed on underpayments and recoveries of erroneous refunds of any taxes imposed by or pursuant to the authority of the Tax Law, or any other taxes administered by the Commissioner of Taxation and Finance, are set by the commissioner on a quarterly basis without promulgation by regulation. The interest rates set by the commissioner are published in the section for miscellaneous notices in the New York State Register, and notice thereof is given by other appropriate means (e.g., posting on the department's website), no later than 20 days preceding the first day of the calendar quarter during which such interest rates apply. Such rates are prescribed in sections 697 (j) and 1096 (e) of the Tax Law and in section 11-1797(j) of the Administrative Code of the City of New York. Reference to taxes in this section includes special assessments, fees, and any other impositions that are administered by the commissioner.
N.Y. Comp. Codes R. & Regs. Tit. 20 § 2393.1