N.Y. Veh. & Traf. Law § 401-B
Every motor vehicle engaged in commercial towing in this state shall be registered and identified as a tow truck, as hereinafter provided. No motor vehicle shall be registered as a tow truck unless it shall have a gross vehicle weight rating of at least eighty-six hundred pounds and the application for such registration is accompanied by proof of financial security which shall meet the requirements of article six of this chapter. Upon payment of the fees set forth in schedule H of subdivision seven of section four hundred one of this article, such a motor vehicle shall be issued a license plate identifying it as a "tow truck". It shall constitute a class A misdemeanor to engage in commercial towing with a tow truck that is not registered pursuant to this section.
N.Y. Veh. and Traf. Law § 401-B