New York Consolidated Laws, Local Finance Law - LFN § 85.20 Demand for payment

a. In any case where a demand for payment is required as a condition precedent to the doing of any act or the commencement of any action or special proceeding pursuant to section 85.10 of this title, the demand shall comply with the provisions of this section.

b. The demand shall be in writing, sworn to by or on behalf of the claimant, and shall set forth: (1) the name and post-office address of each claimant, and of his attorney, if any; (2) the contract, debt or obligation involved; (3) the nature and basis of the claim; (4) the time when the claim arose; (5) the items of damage claimed to have been sustained so far as then practicable; and (6) the nature of the act proposed to be done or of the action or special proceeding proposed to be commenced by the claimant.

c. The demand shall be served on the municipality against whom the claim is made by delivering a copy thereof, in duplicate, personally, or by registered mail, to the person, officer, agent, clerk or employee, designated by law as a person to whom a summons in an action in the supreme court issued against such municipality may be delivered.

d. Anytime after the date of service of the demand for payment and at or before the trial of an action or the hearing upon a special proceeding to which the provisions of this section are applicable, a mistake, omission, irregularity or defect made in good faith in the demand required to be served by this section, not pertaining to the manner or time of service thereof, may be corrected, supplied or disregarded, as the case may be, in the discretion of the court, provided it shall appear that the other party was not prejudiced thereby. Application for such relief, if made before trial or hearing, shall be by motion, on affidavits; if made before the action or special proceeding is commenced, shall be by motion, on the petition of the claimant, or someone on his behalf. Failure to serve more than one copy may be corrected by such motion.