N.Y.C. Admin. Code § 11-1017: § 11-1017 Returns to be secret.

Except in accordance with judicial order, or upon subpoena issued by a court of competent jurisdiction, it shall be unlawful for the commissioner of finance or any officer or employee of the city to divulge or make known in any manner, any information contained in any return required under this chapter. Nothing herein shall be construed to prohibit the delivery to a taxpayer of a certified copy of any return filed by the taxpayer, nor to prohibit the publication of statistics so classified as to prevent the identification of particular returns, or the inspection by the corporation counsel of the return to any taxpayer who shall bring action or proceeding to set aside or review the tax based thereon, or against whom an action or proceeding has been instituted or is contemplated for the collection of a tax or penalty. Returns shall be preserved for three years and thereafter until the commissioner of finance orders them to be destroyed.