Plumbing contractors in Washington

Washington licenses this trade at state level through the Washington State Department of Labor & Industries, so one search covers the whole state. This page holds 3,110 licenses, copied from the L&I file published 2026-10-22. Then say what the job is, and each result says whether the licence reaches it — not just whether it exists.

What this file says about itself

Every figure here is as of 2026-10-22, the day L&I published the file — not as of today. That is deliberate: a count of current licenses recomputed on each page view is a different number every day and a wrong one the moment the refresh stops.

• 3,110licenses in the file
• 2,19571% of the file — unexpired, and recorded by L&I as active
• 68422% of the file — past their expiry date on that date, of which 150 carry a different L&I word — closed, re-licensed, and so on — which is why this is larger than the EXPIRED row below
• 128still live, but due to expire within the following 90 days

That last figure is the reason a license check has a shelf life. 128 of these licenses lapse within three months of the file’s own date unless they are renewed, and a printout of this page taken today can be wrong about any of them by the time the work starts.

L&I’s own words, and how often each appears

L&I publishes a status word for every license, and this page repeats that word rather than working one out from the expiry date. 222 of these licenses carry a word meaning something is wrong while their expiry date was still ahead — the exact combination a date-only reading calls current, and the exact case someone checking a contractor is checking for. A further 9 are unexpired and not active either, and are deliberately not counted with them: L&I records those as replaced — a business that re-registered, usually after a change of legal entity — which is not a finding against anybody. So subtracting the first two figures above from the total reaches 231 rather than 222, and this is where the difference goes.

What each specialty is allowed to do

L&I registers every contractor on this page under one license type — plumbing contractor — and then records a specialty that limits what its holder may work on. Take the commonest job a homeowner hires a plumber for, new or moved plumbing in a house — a bathroom, a kitchen, a repipe: 264 of the 3,110 here hold a specialty the rule says does not reach it, and 0 more hold one where the rule does not settle it. That count is by specialty and nothing else — many of them are registered and current, and their status word is the same word a general contractor’s record carries. The status word is not the thing that separates them.

The limits below are read from WAC 296-400A-010, which sets a scope of work for each certificate; WAC 296-400A-011, which makes the certificate held by a contractor’s designated plumber the scope of work that contractor may perform; and L&I — Plumber certification, which is more specific than the rule in three places and is quoted where it is — the residential specialty’s three storeys, the residential service certificate’s drain cleaning and leak repairs, and the domestic pump’s horsepower. L&I names the designated plumber on the record this page links to. Where the rule does not settle a job, the search above says so rather than guessing.

Which licences reach which job

The picker above asks the reader for the job and the results answer it. This is the same answer, worked out from WAC 296-400A-010 for every job on that list, so it can be read without searching — and so the page states it rather than promising it.

A specialty missing from both columns is one WAC 296-400A-010 does not settle for that job, and it is not guessed at here: those licences, together with the 0 the board left blank, are the ones the search returns as ask L&I. The counts are licences on this file, not specialties — a rule that rules out four specialties can rule out very few holders, or most of them.

L&I prints the specialty on its own record for each license, beside a link captioned What can they do?. This page repeats the word and the rule behind it; the board is still where the answer is confirmed. Each share is rounded and the small ones read under 1%, so that column does not add to exactly 100; the counts add to 3,110.

What a result here means

It means the L&I file of 2026-10-22 recorded that license with that status and expiry date. It does not mean the license is current right now: a license can be suspended or revoked between the board’s files, and this copy would not know. That is why every result links to L&I’s own lookup, and why you should use it before hiring anyone.

If a name is not here

A license issued after 2026-10-22 will not be in this copy. L&I registers contractors by license type, and this page covers the plumbing contractor type only. Individual plumbers are certified separately by L&I and are not on this page.

Washington registers contractors through L&I, and this page covers one license type. A contractor registered under a different type, or under a business name spelled differently from the one you searched, will not appear here even though L&I holds them.

What Washington licenses, and what it does not — and what a license covers, which is less than most people hiring a contractor assume.

The other registers on this site

• Electrical contractors in Texas — TDLR
• Air conditioning contractors in Texas — TDLR
• Barbering and cosmetology establishments in Texas — TDLR
• Electrical contractors in Washington — L&I
• Construction contractors in Oregon — CCB
• Construction contractors in Washington — L&I