Plumbing Licensing in Washington
Do plumbing contractors need a license in Washington?
In Washington, plumbing contractors are generally required to hold a state-issued license from the Washington State Department of Labor & Industries. Always confirm a contractor's license number and current status directly with the WA L&I before you hire.
Source: Washington State Department of Labor & Industries (official record)Find licensed plumbing contractors in Washington
Browse Washington plumbing businesses sourced from the Washington State Department of Labor & Industries public registry — each listing shows its license number and links to the official record.
Browse Plumbing in Washington →How to verify a licensed plumbing contractor in Washington
- Ask for the state license number. Every licensed plumbing contractor in Washington is issued a unique license number by the Washington State Department of Labor & Industries. Ask for it before work begins.
- Look it up with the Washington State Department of Labor & Industries. Enter the license number in the Washington State Department of Labor & Industries's official public license-check record to confirm it is real and current.
- Confirm the license is active and matches the business. Check that the license status is active/clear and that the name on the record matches the business you are hiring.
- Verify the classification covers the work. Confirm the license classification authorizes plumbing work specifically, not just general contracting.
Plumbing licensing in Washington: FAQ
Do plumbing contractors need a license in Washington?
Yes. Washington generally requires plumbing contractors to hold a state-issued license from the Washington State Department of Labor & Industries. The applicable credential is the Plumber certification (RCW 18.106) + contractor registration (RCW 18.27). Confirm the specific scope and any exemptions on the official WA record.
Who issues plumbing licenses in Washington?
Washington State Department of Labor & Industries (WA L&I) issues and maintains plumbing contractor licenses in Washington.
How can I check if a plumbing contractor is licensed in Washington?
Ask for the contractor's state license number and look it up in the Washington State Department of Labor & Industries's official public license record. Confirm the status is active and the name matches.
Does FindTrustedHelp guarantee a contractor is licensed?
No. FindTrustedHelp publishes government-sourced license records with the issuing authority and a link to the official WA record so you can verify status yourself. We do not guarantee any specific outcome, ranking, or hire.
P03 board (wa-lni). Credentials cited to the L&I 'Verify a Contractor' tool (secure.lni.wa.gov/verify).
Source & verification
Licensing requirement and issuing authority for Washington: Washington State Department of Labor & Industries (official .gov record). Credential & basis: Plumber certification (RCW 18.106) + contractor registration (RCW 18.27). FindTrustedHelp summarizes public records and links to the official source; always verify a contractor's current status directly with the WA L&I.