N.Y.C. Charter § 1522: Section 1522. Warrants.

No money shall be paid out of the treasury except on a warrant authorized by law, signed by the comptroller and countersigned by the commissioner of finance which shall refer to the law under and to the appropriation against which it is drawn. No warrant shall be paid on account of any appropriation after the amount authorized to be raised for the purpose specified in the appropriation shall have been expended. In counter-signing warrants drawn by the comptroller, the commissioner shall be under no duty of inquiring as to the legality or propriety thereof but may rely on the comptroller's signature thereto.