Understanding California’s Contractor License Classifications

  • Posted by Melanie Klag
    Understanding California’s Contractor License Classifications

    California requires anyone performing contracting work (or bidding on jobs) that total $500 or more in labor and materials to hold a valid contractor’s license issued by the Contractors State License Board (CSLB). This is, in part, because of CSLB’s mission to protect the public by ensuring construction work is performed safely, professionally, and by qualified contractors. 

    Learn How to Become a Contractor in California.


    California’s Four Core Contractor License Categories 

    CSLB classifies contractor licenses into four key groups: 

    Class A – General Engineering Contractor 

    For work involving "fixed works requiring specialized engineering knowledge and skill," including infrastructure like dams, airports, sewers, bridges, pipelines, power plants, highways, and more. 

    Class B – General Building Contractor 

    A CA General (B) Building license covers structures requiring at least two unrelated building trades, such as homes, offices, schools, barns—anything built for shelter or support. This license does not apply to contractors who only supply materials without fabricating or installing them. 

    Our recent blog explains all the steps you need to take to earn your CA General Building license.


    Class B‑2 – Residential Remodeling Contractor 

    For improvements, alterations, or remodeling of existing residential wood-frame structures, involving at least three unrelated building trades (e.g., drywall, painting, plumbing, electrical). 

    Class C – Specialty Contractor 

    Applies to contractors whose work focuses on a specific trade that requires specialized skill. There are dozens of Class C sub‑classifications (like C‑10 for electrical, C‑36 for plumbing, C‑39 for roofing, etc.). 

    CA C-10 License: Electrical Contractor 

    This specialty contractor license permits a contractor to place, install, erect, or connect electrical wires, fixtures, appliances, apparatus, raceways, conduits, or solar photovoltaic cells, or any part thereof, according to the CSLB.  

    Learn how to become an electrician in California in our blog! 


    Why distinctions matter: 

    • Legal compliance: Performing work under the wrong license risks fines or license revocation.
    • Scope of services: Contractors must match their license to the project type—A for infrastructure, B for general building, B‑2 for remodeling, and C for specialized tasks.
    • Regulatory clarity: Certain trades require C licenses (like asbestos abatement or well‑drilling)—and contractors must hold the correct classification. 

    Why Each License Type Is Needed 

    • Public Safety & Standards: Ensures that contractors possess the skills and knowledge required for specific types of work.
    • Consumer Protection: Helps prevent unqualified or dishonest contractors from doing harm or delivering substandard results.
    • Professional Accountability: Licensing enables oversight, complaint resolution, and enforcement of penalties when needed. 

    Contractor License Qualifications 

    To obtain a CSLB license, applicants generally need to be 18 years of age and demonstrate: 

    • Experience: At least four years of journeyman-level (or higher) experience in the last 10 years, specific to the license classification 
    • Examinations: Successful completion of:
      • A closed-book Law and Business exam (mandatory)
      • A closed-book trade-specific exam for their classification
      • An asbestos open-book exam (if relevant) 
    • Bond and Fees: Submit a contractor’s bond (typically $15,000–$25,000) and pay application and licensing fees.
    • Insurance: Provide proof of workers’ compensation insurance or a self-insurance certificate (if applicable)  

    Applicants must also fulfill administrative requirements, such as fingerprinting and background checks. 

    Which License is Right for You? 

    Navigating California’s contractor license classifications can feel overwhelming, but understanding the differences is essential if you want to work legally, grow your business, and protect your clients.  

    Whether you’re aiming to build large-scale infrastructure as a Class A license holder, manage multi-trade projects under a Class B license, specialize in residential remodels with a Class B-2, or focus on a specific trade with a Class C license, each pathway requires preparation, experience, and passing the CSLB exams. 

    If you’re ready to take the next step in your contracting career, don’t leave exam prep to chance. At Contractor Training Center, we provide tailored study materials and instructor-led prep courses to help you pass your California contractor exam the first time. 

    Explore our California Contractor Exam Prep Courses here and start building your future with confidence! 

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