N.Y. SCT Law § 13-A

§ 13-a. Penalties and payment to county treasurer. (1) After the\nreturn of unpaid taxes by the receiver to the county treasurer, a\npenalty of five per centum of the amount of the unpaid tax shall be\nadded by the county treasurer and charged upon each item thereof and\ncollected when the same is paid, but said penalty need not be entered\nagainst each item where mechanical billing machines are used for\nrendition of tax bills, statements or receipts by the county treasurer.\n (2) The tax and five per cent penalty, plus interest on both such tax\nand penalty computed at the rate as provided in section thirteen-c of\nthis tax act for each month, or part thereof, from the first day of\nFebruary after the tax was levied, may be paid to the county treasurer\nat any time before the first day of September succeeding the date of the\ntax warrant.\n (3) Thereafter, payment of such unpaid taxes may be made at any time\nbefore sale of the land for unpaid taxes, upon payment of such tax,\npenalty, interest on both such tax and penalty computed at the rate as\nprovided in section thirteen-c of this tax act for each month or part\nthereof from the first day of February, and the cost of advertising the\nland for sale for such unpaid taxes as apportioned by the county\ntreasurer among the several parcels liable to be sold.\n