N.Y. Lien Law § 11-b

§ 11-b. Copy of notice of lien to a contractor or subcontractor.\nWithin five days before or thirty days after filing a notice of lien in\naccordance with section ten of this chapter or the filing of an\namendment of notice of lien in accordance with section twelve-a of this\nchapter the lienor shall serve a copy of such notice or amendment by\ncertified mail on the contractor, subcontractor, assignee or legal\nrepresentative for whom he was employed or to whom he furnished\nmaterials or if the lienor is a contractor or subcontractor to the\nperson, firm or corporation with whom the contract was made. A lienor\nhaving a direct contractual relationship with a subcontractor or a\nsub-subcontractor but not with a contractor shall also serve a copy of\nsuch notice or amendment by certified mail to the contractor. Failure to\nfile proof of such a service with the county clerk within thirty-five\ndays after the notice of lien is filed shall terminate the notice as a\nlien. Any lienor, or a person acting on behalf of a lienor, who fails to\nserve a copy of the notice of lien as required by this section shall be\nliable for reasonable attorney's fees, costs and expenses, as determined\nby the court, incurred in obtaining such copy.\n