(1) Except as provided in this chapter, as of July 1, 2021, it is unlawful for any person, firm, partnership, corporation, or other entity to advertise, offer to do work, submit a bid, or perform any work under this chapter without being licensed as a plumbing contractor under this chapter. A plumbing contractor license expires twenty-four calendar months following the day of its issuance. An application for a plumbing contractor license must be made in writing to the department, accompanied by the required fee. The application shall state:

(a) The name and address of the applicant. In the case of firms or partnerships, the application must state the names of the individuals comprising the firm or partnership. In the case of corporations, the application must state the names of the corporation's managing officials;

(b) The location of the place of business of the applicant and the name under which the business is conducted;

(c) The employer social security number or tax identification number;

(d) Evidence of workers' compensation coverage for the applicant's employees working in Washington, as follows:

(i) The applicant's industrial insurance account number issued by the department;

(ii) The applicant's self-insurer number issued by the department;

(iii) For applicants domiciled in another state or a province of Canada subject to an agreement entered into under RCW 51.12.120(7), filing a certificate of coverage issued by the agency that administers workers' compensation law in the applicant's state or province of domicile certifying that the applicant has secured the payment of compensation under the other state's or province's workers' compensation law.

The department may verify the workers' compensation coverage information required by this subsection (1)(d), including information regarding coverage of an individual employee of the applicant. If coverage is provided under the laws of another state, the department may notify the other state that the applicant is employing employees in Washington;

(e) The employment security department number; and

(f) The state excise tax registration number.

(2) The unified business identifier account number may be substituted for the information required by subsection (1)(d), (e), and (f) of this section if the applicant will not employ employees in Washington.

(3) Contractors licensed under this chapter are not required to be registered under chapter 18.27 RCW.

(4) To obtain a plumbing contractor license, the applicant must employ a full-time individual who currently possesses a valid journey level plumber's certificate of competency, or specialty plumber's certificate of competency in the specialty for the scope of work performed. No individual may serve as the certified plumber for any work exceeding the scope of his or her certificate, license, or endorsement.

(5) A plumbing contractor shall:

(a) Ensure that all plumbing work complies with the certification laws and rules of the state; and

(b) Ensure that all plumbing work is performed by properly licensed and certified plumbing individuals.

(6) As of January 1, 2021, for a contractor who employs specialty plumbers as described in RCW 18.106.010(14)(c), and is also required to be licensed as an electrical contractor as required in RCW 19.28.041, while doing pump and irrigation or domestic pump work described in rule as authorized by RCW 19.28.251, the department shall establish a single licensing document for those who qualify for both plumbing contractor license as defined by this chapter and an electrical contractor license as defined by chapter 19.28 RCW.

(7) This section does not apply to: A person who is contracting for plumbing work on his or her own residence, unless the plumbing work is on a building that is for rent, sale, or lease.