California’s Contractors State License Board sorts contractor licenses into four main classifications: Class A for general engineering, Class B for general building, Class B-2 for residential remodeling, and Class C for specialty trades. Each covers a different type of work, and each has rules about what a licensee can and cannot do. Working outside your classification carries the same consequences as working with no license at all — administrative fines, possible criminal charges, and the loss of your right to sue for payment.
When a License Is Required
As of January 1, 2025, Assembly Bill 2622 raised the licensing threshold to $1,000 in combined labor and materials on a single project. The exemption is narrow: the work cannot require any building permit, and the person doing it cannot hire anyone to help.1Contractors State License Board. License Requirement for Minor Work Increases from $500 to $1,000 If either condition applies, a license is required even on a small job.
Property owners can work on their own homes under the owner-builder exemption, but it is tighter than most people assume. For home improvements, the property must be your principal residence and you must have lived there at least 12 months before the work is completed, and you cannot use the exemption on more than two structures within any three-year period. For new single-family construction, you are limited to selling four or fewer homes per calendar year, and all the actual construction work must be performed by licensed subcontractors.2Contractors State License Board. Owner-Builders Beware!
Class A: General Engineering Contractor
Business and Professions Code Section 7056 defines Class A as covering fixed works that require specialized engineering knowledge. The scope is infrastructure rather than buildings people live or work in: irrigation and drainage, dams and hydroelectric projects, highways and tunnels, airports, sewage systems, bridges, refineries, pipelines, railroads, and parks, along with the earthmoving, grading, trenching, and paving connected to them.3California Legislative Information. California Business and Professions Code 7056
Think civil engineering. A Class A licensee builds the road. A Class B licensee builds the office next to it. A Class A contractor who takes on vertical building construction without the right classification is working outside scope.
Class B: General Building Contractor
Business and Professions Code Section 7057 defines Class B as covering projects that build or improve a structure used for shelter — housing for people, animal facilities, or storage for goods and equipment. The classification carries one rule that catches contractors regularly: the project must involve at least two unrelated building trades or crafts.4California Legislative Information. California Business and Professions Code 7057
The B license is a coordination license. It assumes you are managing a project that pulls together multiple trades. A roof-only job belongs to a C-39 Roofing contractor, not a B contractor. A full renovation that involves framing, plumbing, and electrical belongs to a B contractor. A Class B licensee who takes a single-trade job without also holding that specific C classification is violating the law, even if the work itself is done well.
Class B-2: Residential Remodeling Contractor
Business and Professions Code Section 7057.5 created the B-2 for contractors who focus on improving existing homes rather than building new ones. The license is limited to existing residential wood frame structures and requires at least three unrelated trades on each project, one more than the standard B.5California Legislative Information. California Business and Professions Code 7057.5
The restrictions are tighter than many contractors expect. A B-2 licensee cannot make structural changes to load-bearing elements, including footings, foundations, load-bearing walls, partitions, and roof structures. They cannot take contracts involving fire protection (C-16), asbestos abatement (C-22), or well drilling (C-57) unless they hold those specialty licenses or subcontract the work to someone who does.
Electrical, mechanical, and plumbing systems have their own boundary. A B-2 contractor cannot install, replace, or substantially alter these systems or their major components without the appropriate specialty license or a licensed subcontractor. One exception: minor alterations to existing systems to install or replace fixtures, provided the overall contract still includes at least three unrelated trades.
The B-2 fits kitchen and bathroom renovations, cosmetic updates, and multi-trade improvements on older homes. It does not fit a job that involves removing a load-bearing wall or replacing a failing foundation. Those require a full B.
Class C: Specialty Contractor
Business and Professions Code Section 7058 establishes Class C for contractors whose businesses center on a single specialized trade. California recognizes dozens of sub-classifications, each tied to a specific type of work. Some of the most commonly encountered:
- C-10 Electrical: wiring, fixtures, and electrical system installation
- C-20 HVAC: heating, ventilation, and air conditioning
- C-36 Plumbing: water supply, drainage, and gas piping
- C-39 Roofing: roof installation and repair
- C-22 Asbestos Abatement: removal and containment of asbestos materials
Specialty contractors can work directly for homeowners when the job falls entirely within their trade, and they frequently work as subcontractors under a Class A or B general contractor on larger projects. A C licensee cannot take on work in a trade they are not licensed for, even if the task seems simple. An electrician who adds a plumbing rough-in to a job faces the same consequences as any other contractor working outside classification.
A few specialty classifications carry additional insurance obligations. Contractors holding C-8 Concrete, C-20 HVAC, C-22 Asbestos Abatement, C-39 Roofing, or C-61/D-49 Tree Service licenses must carry workers’ compensation insurance at all times, even with no employees. Other classifications can file an exemption if they work solo.6Contractors State License Board. Workers’ Compensation Requirements
Class C-61: Limited Specialty
Construction keeps producing new types of work, and some of it doesn’t fit any established C sub-classification. California Code of Regulations, Title 16, Section 832.61 defines C-61 as a specialty classification limited to a specific field and scope of operations outside the other listed specialty categories.7Legal Information Institute. California Code of Regulations Title 16 Section 832.61 – Classification C-61 Limited Specialty
Each C-61 license carries a “D” sub-code that narrows the scope to a specific type of work. Examples include D-12 for synthetic products, D-34 for prefabricated equipment, and D-49 for tree service. A contractor whose work is highly specialized would typically apply under C-61 with the appropriate D designation rather than trying to fit into a broader C category. Local building departments issue permits based on classification, so the wrong D sub-code can lead to permit denial.
What Happens If You Work Outside Your Classification
California treats unlicensed contracting — and by extension, working outside your classification — as a criminal offense. A first conviction under Business and Professions Code Section 7028 is a misdemeanor punishable by a fine of up to $5,000, up to six months in county jail, or both.8California Legislative Information. California Business and Professions Code 7028 Penalties escalate for repeat offenders:
- Second conviction: a fine of 20 percent of the contract price or $5,000, whichever is greater, plus a minimum of 90 days in county jail.
- Third or subsequent conviction: a fine between $5,000 and $10,000 (or 20 percent of the contract price if higher), plus 90 days to one year in county jail.
Criminal penalties are separate from CSLB administrative action. Civil penalty assessments for unlicensed work under Section 7028 range from $200 to $5,000 per citation. Certain violations, particularly those involving workers’ compensation fraud or the employment of unregistered subcontractors, carry administrative fines up to $15,000.9Contractors State License Board. Approved Assessments of Civil Penalties
The financial consequence that hurts most, though, is loss of the right to collect. California law bars a contractor from using the courts to recover money owed for work performed without the proper license or classification. Quality of work does not matter. Customer satisfaction does not matter. If you were not properly classified when you did the job, you cannot sue to be paid, and the property owner may be entitled to recover money already paid.
Getting Licensed and Checking a License
Qualifying for any California contractor license requires at least four years of journey-level experience in the classification you are applying for, gained within the last 10 years, verified through a certification of work experience form.10Contractors State License Board. Certificate of Work Experience Applicants pass two exams: a trade-specific technical exam and a Law and Business exam. Every licensee must file a $25,000 contractor’s bond before the license activates.11Contractors State License Board. Bond Requirements
Homeowners hiring a contractor should verify not just that the license exists but that the classification matches the work. The CSLB maintains a free online lookup that shows license status, classification, bond information, and complaint history. A C-36 Plumbing contractor who offers to remodel your kitchen is working outside scope, and hiring them for that job puts your own legal protections at risk if the work goes wrong.