Washington plumber license requirements
5 facts reviewed by our editor against the official page. Passages marked “not yet reviewed” are copied word-for-word from official state pages (fetched 2026-10-17) and are pending human review — read them in context on the linked source.
| Item | Detail (with quote from the official source) |
|---|---|
| License levels | Individual worker license Certification as journey level or specialty plumber, typically starting as a trainee. “To become a certified journey level or specialty plumber in Washington, you must typically begin as a” Official source · verified 2026-10-17 · Plumber Certification |
| Experience / hours | Individual worker license Journey level plumber: 4+ years (at least 8,000 hours) as a plumber trainee under a certified journey level plumber. “Four years or more (at least 8,000 hours) working as a plumber trainee under the supervision of a certified journey level plumber.” Official source · verified 2026-10-17 · Plumber Certification |
| Exam | Individual worker license L&I certifies plumbers after confirming on-the-job training hours and a passed exam. “We certify plumbers after confirming they’ve had the appropriate number of hours of on-the-job training, and pass the required exam.” Official source · verified 2026-10-17 · About the Plumber Program |
| Reciprocity & endorsement | Individual worker license Washington has reciprocal certification with Idaho for journey level plumbers; other out-of-state plumbers may present a comparable license or equivalent U.S. military experience. “Washington has reciprocal certification with Idaho for journey level plumbers.” Official source · verified 2026-10-17 · Plumber Certification |
| Other notes | Contractor license Licensed plumbing contractor: $6,000 bond, $250,000 general liability insurance and a designated plumber. “To become a licensed plumbing contractor you need to have a new $6,000 bond, $250,000 general liability insurance, and have a designated plumber” Official source · verified 2026-10-17 · Licensing Requirement FAQs |
Check a license in Washington
Search Washington license holders Data: Washington L&I – Contractor license data (data.wa.gov)
Questions to ask the board
- Which license level matches my experience, and do hours from another jurisdiction count?
- Is the exam open-book, and which code edition is used?
- Do I also need a city or county license where I will work?
- Is there a reciprocity or endorsement agreement with my current jurisdiction?
Sources checked: lni.wa.gov · lni.wa.gov · lni.wa.gov