N.Y. Real Prop. Tax Law § 924-a

§ 924-a. Interest rate on late payment of taxes and delinquencies. 1.\nThe amount of interest to be added on all taxes received after the\ninterest free period and all delinquent taxes shall be one-twelfth the\nrate of interest as determined pursuant to subdivision two or two-a of\nthis section rounded to the nearest one-hundredth of a percentage point,\nexcept as otherwise provided by a general or special law, or a local law\nadopted by a city pursuant to the municipal home rule law or any special\nlaw. Such interest shall be added for each month or fraction thereof\nuntil such taxes are paid.\n 2. The rate of interest applicable to the third calendar quarter of\neach year, as set by the commissioner of taxation and finance pursuant\nto subparagraph (A) of paragraph two of subsection (j) of section six\nhundred ninety-seven of the tax law, shall be the rate of interest\napplicable to unpaid real property taxes for purposes of this section.\nSuch commissioner shall set such rate on or before the fifteenth day of\nJuly in each year. Such rate shall be effective for all warrants issued\nfor a collection period commencing on or after the first day of\nSeptember next succeeding the date the rate of interest is set.\nProvided, however, the rate of interest prescribed by this subdivision\nshall in no event be less than twelve per centum per annum. The\ncommissioner shall inform each affected municipality of any change in\nthe rate established pursuant to this subdivision.\n 2-a. Notwithstanding the provisions of subdivision two of this\nsection, the Schenectady county legislature may adopt, amend or repeal a\nlocal law to prescribe the rate of interest at fifteen per centum per\nannum.\n 3. In any case where a county, by local law, has authorized the\ncollection of such property taxes in installments, such local law may\nestablish an interest rate in such local law to be paid in such\ninstallments which is less than the interest rate provided for in\nsubdivision two of this section. Where such local law does not establish\nsuch a lower interest rate, such rate shall be the rate determined in\naccordance with subdivision two of this section.\n