N.Y. SCT Law § 47

§ 47. When purchasers pay the amounts of their bids; possession of\npremises purchased. The purchasers at such sale shall pay to the county\ntreasurer the full amount of the bid therefor within one week from the\ndate of such sale, and thereupon the county treasurer shall execute to\neach purchaser, including the county, a certificate in writing which\nshall contain a description of the real estate purchased, the amount\npaid therefor, the interest or penalty thereon at which such property\nwas bid, the date of the sale and that the same was sold for unpaid\ntown, county and state taxes or assessments as the case may be, the name\nof the owner of such property as it appears on the books, and such other\ninformation as the county treasurer shall deem expedient. Such purchaser\nor his heirs and assigns may, at any time after the time limited in\nsection forty-nine and section fifty-two of this act for the redemption\nof such premises shall have expired, and the notice therein provided has\nbeen given, and said premises shall not have been redeemed as therein\nprovided and title to such premises shall have been conveyed to him as\nherein provided, and not before, obtain actual possession of the\npremises by an action at law or by causing the occupant of such real\nestate to be removed therefrom, and the possession thereof to be\ndelivered to him in the same manner, and in the same proceedings, and\nbefore the same officers as in a case of a tenant holding over after the\nexpiration of his term without the permission of his landlord.\n