§12–401.

    (a)    A person may engage in the business of providing plumbing services if:

        (1)    the person is a master plumber or holder of a limited master plumber license; or

        (2)    the person:

            (i)    designates a master plumber or holder of a limited master plumber license who actively directs, controls, and is responsible for all plumbing services; and

            (ii)    otherwise provides the plumbing services in accordance with this title.

    (b)    A person may engage in the business of providing propane gas services if:

        (1)    the person is the holder of a propane gas fitter certificate; or

        (2)    the person:

            (i)    designates a holder of a propane gas fitter certificate who actively directs, controls, and is responsible for all propane gas services; and

            (ii)    otherwise provides the propane gas services in accordance with this title.

    (c)    A person may engage in the business of providing natural gas services if:

        (1)    the person is the holder of a master natural gas fitters license; or

        (2)    the person:

            (i)    designates a holder of a master natural gas fitters license who actively directs, controls, and is responsible for all natural gas services; and

            (ii)    otherwise provides natural gas services in accordance with this title.