Contractor advertising rules in Washington: what your website has to say

August 17, 2026 · Joshua Hill

In Washington, a registered contractor has to include the contractor registration number in advertising, and the state's contractor registration law (RCW 18.27) is where that requirement lives. Practically, that means your website, your truck, your yard signs, your print ads, and your directory listings should all carry the number, and your company name in the ad should match the name you are registered under. Everything else in this post is the layer on top of that: what you can claim, what you cannot, and how to check your own site in an afternoon.

This is a plain-language walkthrough written by a contractor, not legal advice. Verify the current requirements with Washington Labor and Industries and, if there is any money or exposure riding on it, with an attorney. Rules change and enforcement details change with them.

The registration number is the part people miss

Most contractors get registered and then never think about the number again. It ends up on the contract and nowhere else. But the requirement is about advertising, and advertising is broader than most people assume: the website, Google Business Profile, Facebook and Instagram business pages, directory profiles, vehicle lettering, door hangers, mailers, and paid ads.

Put it in the site footer so it appears on every page, put it on the contact page, and put it in the profile fields of any directory that gives you a spot for a license number. That single pass covers most of what a customer or an investigator would look at. It also helps you: a visible registration number is checkable, and a homeowner who can look you up in the state's database is a homeowner who trusts the quote a little faster.

Name, scope, and the trades that need their own license

Advertise under the name you are registered under. If you registered as one entity and market under a different brand, the brand needs to trace back to the registration properly, which usually means registering the trade name. Two names in the world and one on file with the state is the kind of mismatch that turns a small complaint into a bigger one.

Scope matters too. General and specialty registrations are not the same thing, and some trades sit under their own separate licensing entirely: electrical and plumbing work are the common examples. Advertising a service you are not licensed to perform is a problem even if you intend to sub it out, so describe what your company does and be straight about what a licensed sub handles.

Claims: the ones that get contractors in trouble

Two rulebooks apply at once. State consumer protection law covers deceptive advertising, and federal FTC rules cover truth in advertising for everyone. Neither one cares whether you meant it.

• Awards, certifications, and manufacturer credentials you do not currently hold, or held once and let lapse.
• "Licensed, bonded, and insured" when one of the three is not true today. Check the bond and the certificate of insurance before you print it.
• Warranty language that is vaguer than what you will actually honor. Write the real terms.
• Prices or discounts with conditions that only show up later, and expiration dates that never expire.
• Reviews and testimonials that were not written by real customers, including incentivized or filtered ones. The FTC has been explicit about fake and suppressed reviews, which we covered in the post on asking for Google reviews.

Also worth saying out loud: photos should be your work. Stock job photos on a contractor site read as stock to anyone who looks twice, and using another company's project shots is its own problem.

How to audit your own site in an afternoon

Open your website and read it as if you were the person who has to prove every sentence. Every claim falls into one of three piles: true and documented, true but undocumented, or aspirational. The first pile stays. The second pile needs the document pulled and filed. The third pile comes off the site today.

Then check the footer for the registration number and the registered name, check the contact page, and check the four or five directory listings that show up when you search your own company. Consistency across those listings is also how the map pack reads you as a real business, which we went through in the map pack post.

What we do in our own companies

We run painting and flooring companies in Bellingham, and the rule we hold to is simple: if a claim on the site cannot be backed by something in a folder, it does not go on the site. Registration number in the footer of every page. Real project photos only. Insurance and bond confirmed current before anything referencing them gets published.

The honest part is that this drifts. A page gets edited, a certification lapses, a new landing page ships without the footer. So it gets checked on a schedule rather than when somebody remembers, and the checklist lives with the rest of the operating documents. That is the same idea behind the system we run: the things that quietly break are the things nobody owns.

This article describes Washington State rules as we understand them as of the date shown. It is not legal advice, and rules change. Confirm the current requirement with the Washington State Department of Labor and Industries or an attorney before you act on it.