Class A: permits the holder to undertake residential, commercial and industrial work.
Class B: permits the holder to undertake residential work, commercial or industrial work under the guidance of a holder of a Class A License.
Class C; permits the holder to undertake residential electrical work, provided the building is a single unit, single floor structure, of not more than 1000 sq ft with a maximum electrical service of 100 amps, or work above this level under the supervision of a holder of a Class A or Class B License.
Class D: permits the holder to undertake basic electrical maintenance of a specific system such as air-conditioning & refridgeration, uninterruptible power supplies (UPS) and stand-by generators.