New York Consolidated Laws, General City Law - GCT § 45-b. Further requirements relating to the business of plumbing

1. No person otherwise qualified shall engage in the trade, business or calling of a plumber or of plumbing in a city of this state as employing or master plumber until he has first procured from the board of health or the examining board of plumbers if so designated by local law in such city a metal plate or sign appropriately lettered or marked “licensed plumber;”  such plate or sign to be conspicuously posted in the window of the place where such business is conducted.  Any person retiring, abandoning or not actually engaged in such trade, business or calling hereinbefore mentioned, shall surrender to the board of health or the examining board of plumbers if so designated by local law of the city such metal plate or sign and shall not again engage in such trade, business or calling until he has again procured a metal sign as herein provided.

2. Within thirty days after this section takes effect, the board of health or the examining board of plumbers if so designated by local law in every city of this state shall prepare metal plates or signs, at least fourteen inches wide and not less than twenty-two inches in length appropriately lettered or marked “licensed plumber,” the lines of each letter to be four inches long and five-eighths of an inch wide;  such plate or sign shall, on some part thereof, contain an identification number, which number together with the name and location of the place of business of the person to whom issued shall be recorded in the office of such board of health or the examining board of plumbers if so designated by local law.  Every person now actually engaged or about to engage in the trade, business or calling of a plumber or of plumbing as employing or master plumber, who has otherwise complied with the provisions of law relating to the conduct of such business upon the payment of five dollars to the board of health or the examining board of plumbers if so designated by local law of such city shall have issued to him a sign or plate hereinbefore described.  Any person to whom such plate or sign has been issued who shall loan, rent, sell or transfer the same to another person whether such person be entitled to receive a similar plate or sign or not, or otherwise wilfully violates the provisions of this section shall be guilty of a misdemeanor punishable by a fine of not exceeding fifty dollars for the first offense, and not less than one hundred dollars nor more than five hundred dollars for a subsequent offense, and in addition thereto shall forfeit his license and certificate of qualifications.

The provisions of this section shall apply to all cities of the state, excluding the city of New York.