Washington contractor license lookup.
Find the business in Washington Labor & Industries’ Verify tool, then check the registration or trade credential that applies to the work.
Start with the business name.
On L&I’s Verify site, search the full or partial business or owner name. Compare the matching identity with the business on your proposal before reading its credentials.
Enter your search on L&I’s website. The official results open there in a new tab.
Reviewed September 8, 2026. This page does not retrieve license records or match contractors to permit histories. Check the current L&I record and save the date of your actual search.
Is it a contractor license or a registration?
Washington uses contractor registration for general and specialty construction contractors. L&I’s registration guidance distinguishes those classifications and identifies additional requirements for certain regulated trades. A broad contractor registration should not be treated as permission to perform every kind of installation.
Read the credential’s actual name and scope. The phrase “licensed contractor” in an advertisement does not tell you which registration, business identifier, or professional credential the business holds.
Source: L&I contractor registration guidance ↗
What can you search in L&I Verify?
L&I supports searches using a business or owner name, contractor license number, employer account ID, or UBI. Its guidance describes information about registration, workers’ compensation, bond-related lawsuits, safety citations, and trade credentials. Available fields should be read in their source context.
A UBI identifies a business; it does not replace the credential for the work. Match the legal business identity before interpreting the other fields. Similar names can belong to different companies.
Source: L&I Verify search methods and record information ↗
Check plumbing and other trade credentials separately
L&I’s plumbing guidance explains that general contractor registration does not substitute for a plumbing contractor license. It also describes the relationship between the plumbing business and the certified people doing the work. Check the appropriate credential for each role instead of assuming one company record answers every question.
If a proposal combines construction with regulated trade work, ask who will perform each part and under which credential. Preserve the business and individual records separately when both are relevant.
Source: L&I plumbing contractor requirements ↗
What if you cannot find the contractor?
Try a partial business name, confirm the spelling, or request the relevant identifier from the contractor. Check that you are searching for the business rather than assuming the individual named on a proposal holds the same record. Ask L&I for clarification when the source remains ambiguous.
A missing search result is not enough to label a business unlicensed. This ObservedWork guide has no contractor-record database of its own, so it cannot establish that a record is absent from the state’s system.
Registration status and permit activity are separate checks
Illustrative example: a business appears in a city permit record under a shortened name, while an L&I result uses a longer legal name. The similarity is a lead for identity research. It does not establish the match without corroborating details.
Likewise, registration standing does not show how recently a contractor worked in a particular city. A permit record may describe an applicant or another project participant. Keep identity, role, geography, and date evidence attached to any claim about observed activity.
A practical verification checklist
- Match the business name and identifier to the proposal.
- Read the registration or license type and current status.
- Check separate trade and individual credentials where relevant.
- Review the supporting fields in the full source record.
- Save the source URL and the actual date of your check.
- Resolve mismatches with the contractor and L&I before relying on the result.
Independent educational guide, reviewed September 8, 2026. L&I provides the official records. A source check does not guarantee workmanship, purchasing authority, or future performance.