N.Y. Comp. Codes R. & Regs. tit. 15 § 81.5
A person doing business in this State who does not have a place of business in this State, but has a place of business or engages in such business in another state, or province of Canada, and who would be required to be registered or certified pursuant to section 415-a of the Vehicle and Traffic Law if it were in this State, shall apply to the commissioner for an identification number. Such identification number shall be issued, provided that such person complies with the laws and regulations of the jurisdiction in which he has his principal place of business or engages in such business. Every out-of-state business required to obtain an identification number pursuant to this section shall display such identification number in the manner provided in subdivision (c) of section 81.4 of this Part on every vehicle whether owned, leased or otherwise hired and used by him for the purpose of transporting junk and salvage vehicles or major component parts of junk and salvage vehicles. This provision shall not apply if a vehicle is hired and already has an identification number on its doors.
N.Y. Comp. Codes R. & Regs. Tit. 15 § 81.5