N.Y. Workers' Comp. Law § 18
Notice of an injury or death for which compensation is payable under this chapter shall be given to the employer within thirty days after the accident causing such injury, and also in case of the death of the employee resulting from such injury, within thirty days after such death. Such notice may be given by any person claiming to be entitled to compensation, or by some one in his behalf. The notice shall be in writing, and contain the name and address of the employee, and state in ordinary language the time, place, nature and cause of the injury, and be signed by him or by a person on his behalf or, in case of death, by any one or more of his dependents, or by a person, on their behalf. It shall be given to the employer by delivering it to him or sending it by mail, by registered letter, addressed to the employer at his or its last known place of business; provided that, if the employer be a partnership then such notice may be so given to any one of the partners, and if the employer be a corporation, then such notice may be given to any agent or officer thereof upon whom legal process may be served, or any agent in charge of his business in the place where the injury occurred. The failure to give notice of injury or notice of death unless excused by the board either on the ground that notice for some sufficient reason could not have been given, or on the ground that the employer, or his or its agents in charge of the business in the place where the accident occurred or having immediate supervision of the employee to whom the accident happened, had knowledge of the accident or death, or on the ground that the employer has not been prejudiced thereby, shall be a bar to any claim under this chapter, but the employer and the insurance carrier shall be deemed to have waived such notice unless the objection to the failure to give such notice or the insufficiency thereof, is raised before the board on the first hearing of the claim field by such injured employee, or his or her dependents at which all parties in interest are present, or represented, and at which the claimant, or principal beneficiary, testifies.
N.Y. Work. Comp. Law § 18