Plumbing Contractors in Washington: market size and renewals

The L&I register lists 3,030 plumbing contractors in Washington. The densest city is Seattle with 140 of them, 4% of the state total. 167 come up for renewal within 90 days.

Where the competition is

Licence counts by city, densest first. Use it to see how contested a patch already is before you spend money marketing into it, or to find the cities where the register is thin.

Renewal pipeline

Licences with an expiry date inside each window, counted from the board file. A licence that has already lapsed or been suspended is excluded, so these are people who currently hold a valid licence and have a renewal coming.

New plumbing contractors per year

How many plumbing contractors currently on the register were first issued in each year. Older years thin out as licences lapse and drop off the file, so read this as the surviving cohort, not as the number issued at the time.

Counted from the Washington State Department of Labor & Industries public licence file, reloaded August 18, 2026. Figures describe licences on record, not businesses: one company can hold several. Confirm anything that matters at L&I.