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Do HVAC Contractors Have to Show a License Number in Ads?
Short answer: In several states, yes. Texas, Oklahoma, Iowa, Nevada and Florida all have written rules that put the contractor license number in advertising, and Nevada and Florida name websites. In other states we found no rule, which does not prove there is none. Put your number in your site footer either way.
- Texas, Oklahoma, Iowa, Nevada and Florida have written rules putting the contractor license number in advertising.
- Nevada's contractors board and Florida's licensing board both name websites as advertising.
- For other states we found no rule, which does not prove none exists.
- EPA Section 608 certification belongs to a technician; it is not a contractor license number.
- Put your license number in your site footer even where no rule applies.
- Rules change and local rules can add more, so check with your own state board.
A contractor license number is the number your state or local board gave your company when it licensed it to install, repair or service heating and cooling systems. A homeowner can type it into the board's lookup and see that you are real.
HVAC is different from some trades because there are two layers of credentials. There is a business or contractor license from a state or local board, which is what this page is about. And there is a federal refrigerant certification for the technician. We explain both below.
We checked the official sources named in each section. Rules change, many are written about "advertising" in general, and local rules can add more. Check with your own board before you rely on this page.
Is a website "advertising"?
Usually, yes. If a page says you do heating and cooling work and tells people how to hire you, a regulator can treat it as an ad. Some boards say so in writing.
Nevada's contractors board says all forms of business advertising must display your license number clearly, and its list includes websites, vehicles, business cards, letterhead, signs and directories (Nevada State Contractors Board: advertising requirements). Florida's licensing board says the number goes on an advertisement, and its definition of "advertise" covers "electronic media including Internet sites" (Florida DBPR: Construction Industry Licensing Board FAQs).
Other states write "advertising" or "written advertising" and do not name websites. In that case, assume a site is covered. It costs you one line of text. We list the rest of a good HVAC site in what an HVAC website should include.
What do the states say? A quick table
These are the states where we opened the official text and found an advertising rule that applies to HVAC or to all contractors.
| State | What the source says | Source |
|---|---|---|
| Texas | Advertising by air conditioning and refrigeration contracting companies that is meant to solicit business must include the license number of the affiliated licensee. Some ads are exempt. | 16 TAC §75.71 |
| Oklahoma | The mechanical contractor state license number must be on all advertising, contracts and bids. | OAC 158:50-5-4 |
| Iowa | Written advertising by plumbing, mechanical and similar contractors must include the contractor license number, as applicable. | Iowa Code ch. 105 |
| Nevada | All forms of business advertising must show the license number. Websites are on the board's list. | Nevada State Contractors Board |
| Florida | License number goes on advertisements, signs, bids, contracts and vehicles that show the company name. Websites count as advertising. | Florida DBPR |
That is not every state. Other states may have home improvement or contractor board rules, and some may require the number in all ads. "We did not find one" means we did not find one, not that none exists.
Texas: what HVAC contractors should know
Texas licenses HVAC work through the Texas Department of Licensing and Regulation. Its air conditioning and refrigeration page says contractors who install, repair or maintain air conditioning, refrigeration or heating systems must hold a TDLR license, and that companies must employ a licensed contractor at each permanent location (TDLR: Air Conditioning and Refrigeration).
The advertising rule sits in 16 TAC §75.71, which covers the responsibilities of the contracting company. Subsection (h) says advertising meant to solicit business must include the affiliated licensee's license number. The section exempts some items: nationally placed TV ads, which may say numbers are available on request, basic phone book listings, and promotional items such as caps and tee shirts (16 TAC §75.71).
The plain reading for a Texas shop: put the license number on your website, your estimates, your truck lettering and your direct mail. See our Texas page for more on how the state works.
Oklahoma and Iowa: the number goes where you advertise
Oklahoma says the mechanical contractor state license number must be on all advertising, contracts and bids. The rule excludes uniforms and promotional items such as pens, pencils, key chains and tape measures from "advertising," but that exception applies only to advertising, so contracts and bids still carry the number (OAC 158:50-5-4). Read our Oklahoma page for the licensing side.
Iowa's rule is for written ads. The state code says ads from people who design, install or repair plumbing, mechanical and similar systems must include the contractor license number, as applicable. It also says only a licensed person may advertise that they hold a state license, and it makes it a simple misdemeanor to falsely claim a license or to list a false license number (Iowa Code ch. 105, section 105.25). Our Iowa page covers more.
Florida and Nevada: websites named outright
Florida's board lists the places the number must appear: any application for a building permit, offer of service, business proposal, bid, contract, advertisement and sign, plus vehicles that display the company name or graphics that would lead a reasonable person to believe it is a contractor's vehicle. Pens, hats, shirts and similar promotional novelties are not covered (Florida DBPR). Florida licenses air conditioning contractors through the same board. Our Florida page goes into it.
Nevada's board calls the website "the digital front door to your business" and lists it with vehicles, cards, letterhead and signs. The page does not name the HVAC classification, but its rule is for "all forms" of business advertising (Nevada State Contractors Board). See the Nevada page.
What about states with no rule we could find?
Ohio is a good example of why you should read your own state's setup. Its state board licenses HVAC and refrigeration contractors under Chapter 4740 of the Revised Code, but that chapter's definition of a construction project leaves out residential buildings as defined in section 3781.06. The same chapter also says it does not limit local rules on HVAC work or on registering tradespeople (Ohio Revised Code Chapter 4740). We found no advertising rule in that chapter. A city may still have its own rules, so check with your local building department. Read the Ohio page for more.
Even where nothing is required, put your number on the site. Here is why:
- Homeowners can look you up and see you are real.
- It sets you apart from unlicensed operators who work from a phone number.
- Google and AI tools read your page for facts like this. A number in plain text is easy to quote.
- If a city or county adds a rule later, you are already covered.
Is the EPA 608 certification a license number?
No. This is where HVAC differs from other trades. Under Section 608 of the Clean Air Act, technicians who maintain, service, repair or dispose of equipment that could release ozone-depleting refrigerants must be certified, and since January 1, 2018, that includes most substitute refrigerants such as HFCs. Certification must come from an EPA-approved organization, and the credential does not expire (EPA: Section 608 technician certification).
That is a certification held by a person, and EPA calls the proof a "Section 608 Technician Certification Card" (EPA: Stationary refrigeration and air conditioning, Section 608). It is not a contractor license number from a state board, and no ad rule we read treats it as one. You can mention that your techs are EPA 608 certified on your About page. It is a trust signal. Do not put it where a license number belongs.
Does the rule cover Google, social media and flyers?
The rules we read say "all advertising," "written advertising" or list items like signs, vehicles and websites. None of the pages we opened named Google Business Profile or Facebook. That is not permission. If a profile or page offers your services, treat it as an ad and put the number with it.
A simple habit works. Anywhere your business name appears next to an offer to do HVAC work, the number goes next to it. That covers your site, your online profiles, your trucks, your cards, your lawn signs, your estimates and your direct mail. Both Florida and Oklahoma say promotional items such as pens are not covered, so you do not have to print it on freebies.
How do you add your HVAC license number to your website?
Step 1: Find the exact format
Look up your license on your board's lookup page. Copy the number and any prefix or class exactly as the board shows it. Some states want a prefix or a license class in the display.
Step 2: Put it in the footer of every page
Write your business name, then the license number, in plain text. Do not put it inside an image. Text can be read by people, by Google and by AI tools.
Step 3: Add it to the home page and contact page
Put it near the phone number. A line such as "Licensed HVAC contractor, license #[your number]" works.
Step 4: Add it to estimates, trucks and online profiles
Match what you did on the website. Check your Google Business Profile (HVAC categories guide), Facebook page and any directory where you offer services.
Step 5: Link to the lookup
If your board has a public lookup, link to it. It lets a careful homeowner verify you in a minute.
Step 6: Recheck once a year
Licenses renew, and numbers or classes can change. Add it to the same calendar reminder as your renewal.
What if you are not licensed yet?
Do not advertise as licensed. A false license claim is one of the worst things you can put on a site. Iowa makes it a simple misdemeanor. If you are working under a licensed company, say that. If you have no site yet, start with do you need a website for your HVAC business. Your state board's website lists the steps to get licensed.
Common questions
Do HVAC contractors need to put their license number on their website?
In some states, yes. Nevada and Florida name websites. Texas, Oklahoma and Iowa require the number in advertising. Where we found no rule, we still suggest a footer line. Check with your own board, because we cannot cover every state or city.
Is an EPA 608 card the same as a contractor license number?
No. The EPA 608 certification is a federal credential for a technician who handles refrigerants. A contractor license number comes from a state or local board and covers the business. Use each for what it is.
Does the license number rule apply to my truck and business cards?
Often, yes. Florida lists vehicles that display your company name, and Nevada lists vehicles and business cards. Texas and Oklahoma say advertising, with some exceptions for items such as caps, shirts and pens. If your board lists it, follow the list.
What happens if I leave my license number off my ads?
It depends on your state, and we did not find a penalty on every page we read. Nevada's board says its general disciplinary authority can include penalties, suspensions or license revocations for breaking its statutes. Whatever the penalty, a board complaint is easy to avoid with one line of text.
Where do I look up the rule for my state?
Start with your state's contractor or mechanical licensing board and search its site for "advertising." Then check your city or county. Our state pages list the board for many states, such as Texas and Florida. If you are building a new site, you can see a free demo site with the license line in the footer.
Sources
- Nevada State Contractors Board: Advertising requirements (2026)
- Florida DBPR: Construction Industry Licensing Board FAQs (2026)
- Cornell LII: 16 Texas Administrative Code §75.71, Responsibilities of the Contracting Company (2026)
- TDLR: Air Conditioning and Refrigeration (2026)
- Cornell LII: Oklahoma Administrative Code 158:50-5-4 (2026)
- Iowa Legislature: Iowa Code chapter 105 (2026)
- Ohio Laws and Rules: Revised Code Chapter 4740 (2026)
- EPA: Section 608 technician certification (2026)
- EPA: Stationary refrigeration and air conditioning, Section 608 (2026)
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