Washington plumbing license lookup: how to check and get a license
Washington plumbing license lookup: who issues plumber licenses (Washington State Department of Labor & Industries (L&I)), how to check one online, the license types, and 2,237 plumbing, heating and air-conditioning contractors by county.
Do plumbers need a license in Washington?
| Who licenses them | Washington State Department of Labor & Industries (L&I) |
|---|---|
| License types | Licensed Plumbing Contractor, Journey Level Plumber (PL01), Residential Plumber (PL02), Residential Service Plumber (PL04), Pump and Irrigation (PL03), Domestic Well (PL03A), Medical Gas Piping Installer (MG01), Backflow (PL30), Plumber Trainee |
| When a license is required | Certificate required for all plumbing work inside a building; plumbing contractor license required to contract plumbing work |
Anyone doing plumbing in Washington must hold an L&I plumber certificate, and plumbing businesses must hold an L&I plumbing contractor license (with a $6,000 bond or assigned savings account) that names a certified designated plumber. Check both the company and the individual plumber in L&I's Verify tool.
How do you look up a plumber's license in Washington?
- Ask the plumber for the license number and the exact business name on the license.
- Open the Washington plumbing license lookup run by Washington State Department of Labor & Industries (L&I).
- Search by license number first. A name search can return several people or companies with similar names.
- Check that the status is active or current, that the license type covers your job, and that the name matches the company on your contract.
- If something doesn't match, ask the plumber about it before you sign or pay a deposit, or contact Washington State Department of Labor & Industries (L&I).
What plumbing licenses does Washington issue?
- Licensed Plumbing Contractor
- Journey Level Plumber (PL01)
- Residential Plumber (PL02)
- Residential Service Plumber (PL04)
- Pump and Irrigation (PL03)
- Domestic Well (PL03A)
- Medical Gas Piping Installer (MG01)
- Backflow (PL30)
- Plumber Trainee
How do you get a plumbing license in Washington?
Licenses are issued by the Washington State Department of Labor & Industries (L&I). Requirements such as experience, exams, insurance and fees change, so read the current rules on the official Washington State Department of Labor & Industries (L&I) source before you apply. Already licensed? List your business on Expert Helper to get matched with customers.
How many plumbers are there in Washington?
The Census Bureau counted 2,237 plumbing, heating and air-conditioning contractors with employees in Washington in 2023. The counties with the most:
| King County | 468 |
|---|---|
| Snohomish County | 325 |
| Pierce County | 271 |
| Clark County | 199 |
| Spokane County | 179 |
| Kitsap County | 87 |
| Thurston County | 76 |
| Yakima County | 70 |
What do Washington homes mean for plumbing work?
The median home in Washington was built in 1984, 36% of households rent and 67% of homes are single-family houses. 34% of homes heat with utility gas and 58% with electricity, and 1% with fuel oil.
How do you choose a plumber in Washington?
- Ask for the license number and look it up yourself on the state or city license search. Licensing is set by the state in some places and by the city or county in others.
- Ask whether the job needs a permit. Water heater swaps, gas work and moving fixtures often do, and the licensed plumber pulls it.
- Get the price in writing: a flat rate for the job, or the hourly rate, the trip fee and how parts are billed.
- For emergencies, ask what the after-hours rate is before the plumber drives out.
- Ask who does the work. A licensed master can send helpers, but the license holder is responsible for the job.
Plumbers in other states
Sources: Washington licensing agency (linked above); US Census Bureau County Business Patterns 2023 and ACS 2023 5-year estimates.