CSLB Advertising Guidelines for California Contractors

The California Contractor State License Board (CSLB) regulates licensed contractors in California and enforces laws related to contractor licensing and advertising. The CSLB has established advertising guidelines that all licensed contractors must follow when promoting their services. Violating these guidelines can result in disciplinary action against a contractor's license.

Title 10 of the California Code of Regulations contains the CSLB's advertising regulations. The main purpose of these regulations is to prohibit false, misleading or deceptive advertising by contractors. The rules seek to ensure that contractors provide accurate and honest information to consumers so they can make informed decisions when hiring a contractor.

What aspects of your business are regulated by CSLB’s advertising guidelines?

Some key requirements of the CSLB advertising guidelines include:

License Number

Contractors must include their license number in all advertising, including business cards, stationery, websites, flyers, etc. Consumers can verify a license number on the CSLB website. The penalty for a first offense of failure to comply with this requirement is between $100 and $1,000.


Advertising must state the type of contractor's license held along with the license number, and you must not advertise any kind of contracting work for which you do not have a license. General building contractor licenses are designated as "A" or "B" while specialty licenses are designated "C" followed by a specific classification number.

Business Name

Advertising must include the full business name registered with the CSLB exactly as it appears on the license.

Expiration Date

License expiration dates must be included.

Responsible Managing Officer

Advertising by corporate license holders must include the name of the responsible managing officer (RMO) along with the license number.

False or Misleading Statements

It is prohibited for contractors to disseminate any advertising that is false, fraudulent or misrepresents a material fact. This includes misleading claims about the scope of the license, abilities, credentials or qualifications held.


Advertising cannot contain an offer of special inducement such as a gift, discount or concession that is conditioned upon the purchase of a job. However, contractors are allowed to advertise bona fide discount and rebate offers.


You may not mention any reference to having a California contractor license bond in any public presentations or advertising. A consumer may take this statement to mean that bonding provides a higher level of protection than is actually the case.

Free Services

Advertising cannot offer any services or items free of charge that are normally included as part of the services being offered.

Code Violations

 Contractors cannot claim in their advertising to perform services for which they are not properly licensed.

License Required

A statement that the contractor is licensed in California must appear on vehicles, forms, websites, contracts and documents used to administer the contracting business.


Guarantees offered on any contracting work cannot be advertised unless the contractor has a valid prepaid home improvement contract registration.

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What advertising platforms are regulated by the CSLB?

The CSLB has requirements about the clarity and accuracy of advertising, but there are also some specifications about where these advertisements are allowed and what platforms are regulated by the CSLB.


Websites must display the contractor's exact license name, classification and license number. Contact information such as business address, phone number and email must be current. Website content should focus on the services provided within the scope of the license and not make misleading claims about abilities or areas of expertise.

Social Media

Social media profiles used for professional purposes must include the contractor's license details. Facebook business pages, LinkedIn profiles, Instagram accounts and other social media platforms are all considered advertisements.

Search Listings

Online directory listings and paid search ads must display the license number and name registered with the CSLB. Abbreviations or alternate versions that omit required details are not compliant.


Any printed advertisements such as flyers must contain the contractor’s license number, classification and expiration date. Distribution of flyers with missing license details violates CSLB regulations.

Vehicle Signage

Contractors must prominently display their business name, license number, classification and expiration date on all commercial vehicles used regularly for work. Lettering should be legible from a reasonable distance.

C-57 Well Drilling, C-45 Sign, and C-36 Plumbing contractors are required to display their company name, address, and license number in letters that are at least 1 ½ inches tall on each side of every professionally registered vehicle.

All other contractors are required to prominently display their company name and contractor license number in print type with a minimum font size of 72 points, or letters that are at least ¾ of an inch high and wide, on each of their commercially registered vehicles.

Radio/TV Ads

Spoken radio and television advertisements must verbally state the contractor's CSLB-registered business name and license number. Fine print disclaimers do not satisfy the CSLB advertising requirements.

Phone Book Listings

Telephone directory listings must include the license number and contractor's legal business name and classification as registered with the CSLB.

Door Hangers

Contractor advertising in the form of door hangers left at residential homes must display the contractor's license number and legal business name.


Large outdoor billboard advertisements require the contractor's license number, full business name, classification and expiration date to meet CSLB rules.


Sponsoring events, sports teams or organizations requires advertising disclosures of the contractor's license details. This applies to any public recognition of sponsorship.

Print Ads

Any ads placed in local newspapers and magazines must list the contractor's license number, business name, classification and expiration date.

Direct Mail

Postcard advertisements sent by mail must feature the contractor's license number prominently. The license number should be noticeable at a quick glance.


Imprinted promotional giveaways like pens, hats or calendars must include the contractor's CSLB license number, legal business name and classification.


All contractors are required to include their license numbers on

  • Business cards
  • Any contract proposals
  • Signs or billboards identifying you or your company as a contractor
  • Any soliciting brochure, pamphlet, circular, or Internet ad you or anyone else posts or distributes
  • Clothing items that include your company name or logo
  • Directories or listings that state or imply you are a contractor requesting or looking for the kind of work that requires a contractor license under California Contractors License Law.

What happens if I violate these guidelines?

The CSLB takes advertising violations very seriously. When violations occur, the CSLB will contact the contractor to order immediate discontinuation of the advertising. The Board may also issue a citation and fine against the contractor's license. Multiple or willful violations can lead to license suspension or revocation.

What can I do to avoid violating the CSLB guidelines?

To ensure full compliance, contractors should carefully review their advertising content such as websites, flyers, business cards, and vehicle signage. It's also recommended that contractors periodically complete the CSLB's self-audit checklist to identify any problems or omissions with their advertising. Staying up-to-date on advertising regulations will help contractors avoid disciplinary action from the CSLB that could tarnish their reputation and negatively impact their business. Following the guidelines shows a commitment to honest and ethical business practices.


By thoroughly reviewing all contractor advertising and marketing content for CSLB compliance, California contractors can avoid violations, fines and disciplinary action. Staying up-to-date on regulatory guidelines shows a commitment to consumer protection. Please let us at SuretyNow know if you need a bond or any clarification on CSLB's advertising guidelines.