What must a licensed plumber display on both sides of all service vehicles?

A licensed plumber is required to display the name of the company and the master plumber number on both sides of all service vehicles to ensure compliance with state regulations. This requirement is designed for public safety and accountability, as it allows customers and regulatory authorities to easily identify the service provider and verify their credentials. Displaying the company's name promotes professionalism and builds trust with clients, while the master plumber number indicates that the individual has met the necessary training, experience, and licensing standards required by the state. This identification on service vehicles helps to ensure that the plumbing services provided are legitimate and that the workers are qualified, which is paramount in maintaining industry standards and public safety.