A license number tells a homeowner you exist on paper, that a state board can hear a complaint about you, and that you’re not the person who knocked on their door yesterday. Some states go further and require it. Here’s what a few say. This isn’t legal advice, and rules change, so always check your own board.
| State | Who | What it says |
|---|---|---|
| Texas | Plumbing companies | Advertisements must include the license number of the Responsible Master Plumber. Estimates and invoices carry a notice about the Texas State Board of Plumbing Examiners with its contact information. |
| Arizona | Licensed contractors | The Registrar of Contractors requires the license number on advertising; its guidance for websites calls for it on the home page. |
| Oregon | Contractors | The Construction Contractors Board number goes on advertising, including websites. Homeowners can look it up on the CCB’s search. |
| Oklahoma | Roofers | Registered roofers with the Construction Industries Board must show the registration number, with an OK prefix, on advertising, contracts and bids. |
| Florida | Electrical contractors | The certification or registration number must appear on every advertisement, website included. |
Where to put it
- The footer of every page, as a baseline.
- The home page, visibly, if your state asks for it there.
- Your contact and about pages, where people look when checking you out.
- With a link to the state lookup, so verifying takes one tap.
More than one license?
List each one with its type: a state contractor license, a city license, a master electrician license, an EPA lead-safe firm certification. If a different person holds the license the company works under, show it the way your board specifies.
If your state doesn’t license your trade
Some don’t at the state level; cities or counties might. Show whatever local license, registration or bond you hold, and say that you pull permits. That line does much of the same work.
How do you find your state’s advertising rules?
- Find the board or agency that issues your license.
- Look for rules on advertising, often in the board’s rules or the statute itself.
- Check whether “advertising” includes websites. It usually does.
- Note exactly what must appear: the number, the license holder’s name, the license type.
- Check city or county rules too, if you hold a local license.
- When in doubt, call the board.
Does a license number help with search and AI results?
Indirectly. A license number shown on your site, consistent with the state’s public record and your Google profile, helps confirm your business is real, which search engines and AI tools weigh when deciding whom to show and cite. It also helps homeowners, which leads to calls and reviews, the signals that matter most.
A license display checklist
- The number in the footer of every page.
- On the home page, if your state asks for it there.
- The license type and holder’s name, where required.
- A link to the state’s public lookup.
- Insurance and bonding, stated plainly.
- The same details on your Google profile and estimates.