STATE LICENSE
RequiredWashington State Department of Labor & In…
Washington replaced plumbing contractor registration with a plumbing contractor license. As of July 1, 2021 it is unlawful to advertise, offer to do work, submit a bid or perform plumbing work without being licensed as a plumbing contractor. The license expires 24 calendar months after issue. RCW 18.106.400(3) then does something no other Washington trade gets: it states that contractors licensed under chapter 18.106 RCW are not required to be registered under chapter 18.27 RCW.
The license is conditioned on people, not on a company exam. To obtain it the applicant must employ a full-time individual who holds a valid journey level plumber's certificate of competency, or a specialty certificate covering the scope of work performed. If the contractor stops employing that person, the license may be suspended or revoked.
Individual certification is the long road. Journey level (PL01) takes four years and at least 8,000 hours as a plumber trainee, of which at least 4,000 must be commercial or industrial. Residential (PL02) takes 6,000 hours, residential service (PL04) 4,000, pump and irrigation (PL03) 4,000 plus electrical certification. Certificates renew on the holder's birthdate every three years with 24 hours of continuing education, and the late fee is a second full renewal fee.
The state sets the license floor; the county or city permit office controls filing, inspections, and local rules wherever the job site sits.
Plumbing permits are local but the license is checked at the counter. RCW 18.106.440 bars any city, town or county from issuing a plumbing permit for work to be done by a contractor required to be licensed under chapter 18.106 RCW without verifying that the contractor is currently licensed, and requires the jurisdiction to print the plumbing contractor license number on the permit and hand the applicant written notice of the licensing laws and the risk of using an unlicensed plumbing contractor. Falsifying information to claim an exemption forfeits the permit. Seattle SDCI, Tacoma, Spokane and King County Permitting each issue and inspect plumbing work under the statewide building code; none of them issues a plumbing credential of its own, and RCW 18.27.130 keeps contractor licensing exclusively at the state level.
The local offices section below names the exact permit desk for every Washington county on file.
Each row names the issuing authority, cost, timeline, citation, and status behind the requirement — verified against the official source.
Published fees from the issuing authorities, as of September 2026. Local permit fees vary by project and jurisdiction — the basis is stated where a flat number does not exist.
A journey level, residential or residential service plumber who misses the deadline pays the $242.70 renewal plus a $242.70 late fee - $485.40 total - and cannot renew online.
Depending on application date and birthdate, an initial plumber certification runs a minimum of 25 and a maximum of 37 months. Fees are the same either way and are not pro-rated.
Laws of 2026 ch. 178 rewrites the suspension trigger in RCW 18.106.270 effective January 1, 2027: five or more infractions determined by final order within a five-year period, with multiple violations from one inspection counted as one.
A practical sequence for a new plumbing contractor in Washington. Actual agency processing times are noted in the ledger above.
Each item names the issuing authority, cycle, and citation.
Statutory consequences with their citations — not estimates, not “commonly cited” guesses.
A person found to have committed an infraction under RCW 18.106.020 is assessed a minimum $100 for a first infraction; a contractor is assessed a minimum $500 for a first infraction. The administrative law judge may not waive, reduce or suspend the monetary penalty.
An individual or plumbing contractor with five or more infractions within the period set by statute may have the certificate, license, endorsement or registration suspended for up to two years.
Failure to have or maintain payroll and other records for each employee performing plumbing work is a violation subject to an infraction, and L&I may assess a penalty for failure to maintain adequate records.
Inside city limits, the city office listed here issues the permit; the county office serves unincorporated areas. Every office links to its official page.
Every fact in this file was checked against these official sources on September 2026.
Pending verification: The continuing-education split for journey level and residential specialty renewals reported by L&I course guidance - 12 hours Uniform Plumbing Code plus 4 hours industry-related electrical within the 24 - was not confirmed on the certification pages fetched. · Plumber trainee certificate fees and the annual trainee renewal amount were not retrieved.
General information, not legal advice. Always confirm requirements, deadlines, and forms with the issuing authority before filing or contracting.
Store licenses, permits, policies, and renewal dates in one place.