License numbers on HVAC websites: what state rules say

In California, Texas and Florida, contractor license numbers must appear in advertising, and websites should be treated as advertising. California's CSLB lists website content as advertising, Texas rule 16 TAC 75.71 requires air conditioning and refrigeration contracting companies to include the licensee's number in advertising, and Florida law requires the certificate or registration number in advertisements regardless of medium. Other states have their own rules.

Why this matters for your website

A license number on your site does two jobs. It meets a legal requirement in many states, and it gives homeowners a way to check you are who you say you are. Contractor boards in several states run public license lookups, and a visible number makes that check easy.

Missing license numbers are a common gap on contractor sites. They are often in the footer of the home page but missing from landing pages, ad pages or social profiles. If your state treats online content as advertising, each page that solicits work may need it.

California

California's Business and Professions Code section 7030.5 requires licensed contractors to include their license number in construction contracts, subcontracts and calls for bid, and in all forms of advertising as prescribed by the registrar. The Contractors State License Board explains in its newsletter guidance that CSLB rules treat advertising broadly, listing business cards, vehicle signs, internet ads, directory listings and "any electronic transmission, including your company's website content."

CSLB guidance also describes vehicle display rules. Civil penalties are set in California Code of Regulations, title 16, section 884: the current text lists a range of $100 to $1,000 for violations of section 7030.5 and caps the total penalty in most citations at $8,000. CSLB published proposed amendments to section 884 in April 2026, so check the version in force when you read this.

For your website: show your CSLB license number on every page that offers services, typically in the header or footer, and on any standalone landing pages used for ads.

Texas

Texas regulates air conditioning and refrigeration contractors through the Texas Department of Licensing and Regulation. Under 16 Texas Administrative Code section 75.71(h), all advertising by air conditioning and refrigeration contracting companies designed to solicit that business must include the affiliated licensee's license number, with listed exceptions. One covers telephone solicitations: the caller does not have to read out the number if they state that the company complies with the state's licensing requirements, but the licensee's number must be provided on request. Others cover nationally placed television ads that say license numbers are available on request, basic telephone book listings, promotional items of nominal value, office letterheads and printed forms, and signs at the contractor's permanent business location.

The same rule requires the license number and company name on both sides of company vehicles in letters at least two inches high, and the licensee's number on proposals and invoices. The rule text does not name websites specifically, but a website that solicits air conditioning or refrigeration work reads naturally as advertising, so displaying the number is the cautious approach.

For your website: show the affiliated licensee's TACLA or ACR license number in the footer of every page and on any ad landing pages.

Florida

Florida Statutes section 489.119(5)(b) states that the registration or certification number of each contractor shall appear in each offer of services, business proposal, bid, contract or advertisement, regardless of medium, as defined by board rule. Under section 489.119(5)(d), the term advertisement does not include business stationery or promotional novelties such as balloons, pencils, trinkets or articles of clothing.

For your website: show your certificate or registration number on every page that offers services. "Regardless of medium" leaves little room to argue that a website is different.

Comparing the three states

This table summarizes the rule text as published. It is not legal advice. Regulators can update rules and guidance, so check the current versions.

Checking your own state

Licensing for HVAC work is set at the state level and sometimes at the city or county level too. To check your obligations:

1. Find your state's licensing body for HVAC or mechanical contractors. It may be a contractor board, a department of labor or a professional regulation agency.
2. Search its rules or statutes for "advertising" and "license number."
3. Look for guidance or FAQ pages, which often give examples of what counts as advertising.
4. Check whether your city or county issues a separate license with its own display rules.
5. If anything is unclear, ask the board directly or check with an attorney who works with contractors.

How to display the number well

• Use text, not an image. It stays readable, searchable and accessible to screen readers.
• Label it clearly. "California CSLB License #000000" or "Texas ACR License TACLA00000C" tells people what it is.
• Keep it consistent. Use the same format on the site, your Google Business Profile, trucks and invoices.
• Include all relevant licenses. If you hold separate licenses for different trades or states, list each where it applies.
• Add a lookup link. Linking to your state's public license search lets homeowners verify you in one click.

Common mistakes

• License number only on the home page, missing from service and landing pages.
• License number as part of a logo image.
• An expired license number left on the site after renewal changed it.
• One state's number shown on pages targeting a different state where you hold a separate license.
• Claims such as "licensed and insured" with no number at all in a state that requires one.

Social media, ads and directories

The same rules that apply to your website usually apply to your other advertising. If your state requires a license number in advertising, check your Google Business Profile description, social media profiles, paid ads, directory listings and printed materials as well. California's CSLB guidance lists directory listings and internet ads among the forms of advertising, and Florida's statute covers advertisements regardless of medium. A quick audit of every place your company appears online is worth doing once a year.

A quick audit you can do today

Open your website and search each page for your license number. Note every page that offers services and does not show it. Then check your Google Business Profile, your main social profiles and any landing pages used for ads. In most cases the fix is a one line change to a shared footer, which updates every page at once.

Disclosure: the owner of this site has commercial interests in web design services. This page is written to be useful whether or not you hire anyone, and it contains no paid placements.