Can a Class B contractor do plumbing in California?

A Class B contractor cannot self-perform plumbing work unless they also hold a C-36 Plumbing license. On a multi-trade project, the B contractor must subcontract plumbing to a licensed C-36 contractor. Plumbing counts as one of the two unrelated trades required for a B contractor to take a prime contract, but self-performance requires the C-36 classification.

What is the difference between a Class B and Class B-2 contractor license?

A Class B license covers new construction and remodeling on any structure when the project requires framing or two or more unrelated building trades. A Class B-2 license is limited to nonstructural improvements on existing residential wood-frame buildings only, requires three or more unrelated trades per contract, and does not allow structural changes or new construction.

Do I need a contractor license for a $700 job in California?

Under AB 2622 (effective January 1, 2025), an unlicensed person may perform work valued at under $1,000 in total combined labor and materials — but only if no building permit is required for the work, no additional workers are hired, and any advertising discloses the person is unlicensed. If a permit is required, a contractor's license is required regardless of the dollar amount.

How many contractor license classifications does CSLB issue?

CSLB issues licenses in four main groups: Class A (General Engineering), Class B (General Building), Class B-2 (Residential Remodeling), and Class C (Specialty). The Class C group contains 42 separate trade classifications, plus the C-61 Limited Specialty which has its own subcategories. In total, CSLB issues over 44 distinct contractor classifications.

Can a Class B contractor do roofing in California?

A Class B contractor can include roofing as part of a project that involves at least one other unrelated building trade. However, a B contractor cannot take a standalone roofing-only contract or a roofing-only subcontract without also holding a C-39 Roofing license.

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California Contractor License Classifications 2026: A, B, B-2 and C Licenses Explained

Q: Can a B-2 contractor do structural work on a small house?

No. A Class B-2 Residential Remodeling contractor is prohibited from making structural changes to load-bearing portions of a structure, including footings, foundations, load-bearing walls, partitions, and roof structures — regardless of project size. Any structural work requires a full Class B General Building Contractor license.

California's CSLB issues licenses across four main categories and 42 specialty trades. This guide covers every classification, who needs which one, and the rules that catch contractors off guard — including the two-trade rule, the new $1,000 threshold, and the workers' comp timeline.

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Last Updated: May 2026. Reflects AB 2622 ($1,000 licensing threshold effective January 1, 2025), SB 1455 (workers' comp universal deadline extended to January 1, 2028), and the CSLB official Description of Classifications (June 2024 edition).

Quick Summary

CSLB issues four license groups: A (Engineering), B (General Building), B-2 (Residential Remodeling), and C (42 specialty trades)
Class B is the most common license — it covers structures requiring framing or two or more unrelated building trades
Class B-2 is limited to nonstructural remodels of existing residential wood-frame buildings with three or more trades
All applicants must document four years of journey-level experience and pass two exams
Every applicant takes the Law and Business exam plus the trade exam for their specific classification
A $25,000 contractor's license bond is required before the license is issued
As of January 1, 2025 (AB 2622), any project at or above $1,000 requires a licensed contractor in the correct classification

What Is the CSLB?

The Contractors State License Board is California's licensing authority for the construction industry. It is a 15-member board with an appointed executive officer and roughly 400 employees, operating under the Department of Consumer Affairs.

The CSLB sets eligibility standards, administers the trade and Law and Business exams, enforces contractor regulations, handles complaints, and regulates advertising. For contractors, a CSLB license is not just paperwork — it is what validates your professional standing and keeps you eligible to bid, contract, and get paid.

In California, any project with a combined labor and materials cost of $1,000 or more requires a licensed contractor in the appropriate classification. Operating without one can void contracts, trigger refund orders, and expose the contractor to criminal penalties.

The Four Main License Groups

CSLB organizes licenses into four groups, defined in California Business and Professions Code (BPC) §§7056 to 7059. You can hold multiple classifications. Many contractors carry a Class B plus one or more Class C licenses.

Class	Name	New Construction?	Commercial?	Structural Work?	Trades Per Contract
A	General Engineering	Civil works only	Civil works only	Engineering	N/A
B	General Building	Yes	Yes	Yes	2 unrelated
B-2	Residential Remodeling	No	No	No	3 unrelated
C	Specialty (42 trades)	Within trade scope	Within trade scope	Within trade scope	Single trade

Class A: General Engineering Contractor

Per BPC §7056, Class A covers fixed works requiring specialized engineering knowledge: irrigation, drainage, water supply, flood control, harbors, dams, levees, railroads, highways, tunnels, airports, sewers, bridges, pipelines, refineries, power plants, mines, large earthmoving and grading, and concrete or paving connected to any of the above.

Class A is the right fit for civil works contractors, heavy highway builders, utility installers, large-scale graders, and bridge or dam specialists. It does not cover building structures designed for human occupancy unless those buildings are incidental to the engineering project.

Class B: General Building Contractor

Per BPC §7057, Class B covers any structure built for the support, shelter, and enclosure of persons, animals, chattels, or movable property, requiring at least two unrelated building trades. This is the most common classification for residential and commercial general contractors. For a deeper look at this license specifically, see the California B License guide.

The two-unrelated-trades rule: A Class B contractor can take a prime contract or subcontract only if the project requires at least two unrelated building trades, the project is for framing or carpentry only, or the contractor holds the appropriate C-classification (or subcontracts to one). Framing and carpentry do not count toward the two-trade requirement when other trades are involved — this is one of the most tested rules on the B trade exam.

Two trades B contractors cannot touch alone. Even on a qualifying multi-trade project, a Class B cannot contract for work that includes C-16 Fire Protection (fire sprinkler systems) or C-57 Well Drilling without holding the relevant C-license or subcontracting to one. Solar work qualifies as two unrelated trades, so B contractors can take active solar energy projects.

Class B-2: Residential Remodeling Contractor

Created by BPC §7057.5, Class B-2 is a narrower license for remodeling existing residential wood-frame structures. It does not authorize new construction or structural changes. Each B-2 contract must require at least three unrelated building trades.

What B-2 contractors can do. Drywall, finish carpentry, flooring, insulation, painting, plastering, roof repair, siding, tiling, and installing or replacing electrical fixtures (dimmers, fans, lights, outlets, switches), plumbing fixtures (faucets, sinks, toilets, tubs), and mechanical fixtures (air filters, grills, preassembled exhaust fans).

Hard limits. A B-2 contractor cannot take any contract with fewer than three unrelated trades; do C-16, C-22, or C-57 work without a licensed sub; make structural changes to load-bearing portions of a structure; or install, replace, or substantially extend electrical, mechanical, or plumbing systems beyond fixture-level work.

Common B-2 Misconception: Many contractors assume a B-2 license covers structural work on small or older homes. It does not. If a remodel involves moving a load-bearing wall, changing a foundation, or modifying a roof structure, a full Class B license is required — regardless of project size. A B-2 contractor who performs load-bearing work is operating outside their classification.

Class C: Specialty Contractors

A Class C contractor's principal business involves a specialized building trade. CSLB issues 42 separate C classifications plus the C-61 Limited Specialty. Each requires its own trade exam in addition to the Law and Business exam.

Structural and Framing

C-5 Framing and Rough Carpentry. Form work, framing, sub-flooring, siding, exterior staircases, overhead doors, roof decking, trusses, sheathing.
C-8 Concrete. Forms, pours, places, and finishes concrete (mass, pavement, flat work, screeds). Not reinforcing steel or plaster-only work.
C-21 Building Moving/Demolition. Raising, lowering, underpinning, demolishing, moving structures and foundations.
C-29 Masonry. Concrete units, clay products, glass and clay block, stone, terra cotta, fire brick. Structural and non-structural walls and fences.
C-50 Reinforcing Steel. Steel mesh and reinforcing bars for concrete structures.
C-51 Structural Steel. Structural steel shapes and plates as structural members.

Systems: Electrical, Plumbing and Mechanical

C-4 Boiler, Hot-Water Heating and Steam Fitting. Power boilers, hot-water heating, steam fitting, and associated solar heating equipment.
C-7 Low Voltage Systems. Communication and low-voltage systems up to 91 volts (telephone, sound, cable TV, CCTV, satellite, instrumentation, low-voltage landscape lighting). Not low-voltage fire alarms.
C-10 Electrical. All electrical work and solar photovoltaic systems.
C-11 Elevator. Electric, hydraulic, and manual elevators and all components.
C-16 Fire Protection. Fire protection systems and equipment. Not electrical alarm systems. Class B and B-2 cannot self-perform this work.
C-20 Warm-Air Heating, Ventilating and Air-Conditioning. Warm-air HVAC, water-heating heat pumps, ducts, controls, and solar HVAC.
C-36 Plumbing. Water supply, waste disposal, gas and liquid piping, water heating, solar water heating, backflow preventers, gas earthquake valves.
C-38 Refrigeration. Refrigerators, refrigerated rooms, A/C units, and controls for temperatures below 50°F (10°C).
C-46 Solar. Thermal and PV solar systems. Cannot perform other building trades except as needed for the solar install.
C-55 Water Conditioning. Water conditioning equipment and incidental piping.
C-57 Well Drilling. Water wells and pumps by boring, drilling, casing, and cementing. Class B and B-2 cannot self-perform this work.

Exterior, Site and Civil

C-12 Earthwork and Paving. Cuts, fills, excavation, grading, trenching, paving, and explosives where needed.
C-13 Fencing. All fences, corrals, railings, guard rails, playground equipment, posts, flagpoles, gates. Not masonry walls (C-29).
C-27 Landscaping. Landscape systems, gardens, grounds, and site grading for landscaping.
C-31 Construction Zone Traffic Control. Lane closures, flagging, and traffic diversions using portable devices on roadways.
C-32 Parking and Highway Improvement. Protective coatings, vehicle stops, guard rails, lines, markers, and signs on parking lots, airports, and highways. Not re-paving.
C-34 Pipeline. Pipelines for water, gas, and petroleum, with associated trenching and surface restoration.
C-39 Roofing. Surfaces that seal, waterproof, and weatherproof structures using asphalt, tar, felt, foam, metal, shakes, shingles, tile, or slate.
C-42 Sanitation System. Cesspools, septic tanks, storm drains, and sewage and drain structures.
C-43 Sheet Metal. Cornices, flashings, gutters, kitchen equipment, ductwork, patented chimneys, metal flues, and metal roofing.
C-49 Tree and Palm. Planting, maintenance, and removal of trees and palms; pruning, stump grinding, and guying.

Interior Finishing and Decorative

C-2 Insulation and Acoustical. Insulating and acoustical materials for temperature and sound control.
C-6 Cabinet, Millwork and Finish Carpentry. Cabinets, sashes, doors, trims, non-bearing partitions, and finish carpentry.
C-9 Drywall. Gypsum wall board, non-structural metal framing, taping, and texturing.
C-15 Flooring and Floor Covering. Carpet, resilient sheet, resilient tile, and wood floors. Not ceramic tile (C-54).
C-17 Glazing. Glass and glass-substitute materials, frames, panels, sashes, and doors.
C-23 Ornamental Metal. Decorative metal (brass, bronze, copper, iron, stainless steel) for architectural treatment. Not sheet metal (C-43).
C-33 Painting and Decorating. Paints, papers, textures, varnishes, stains, fillers, and waxes for decoration, protection, fireproofing, and waterproofing.
C-35 Lathing and Plastering. Plaster coatings, lath, channel work, and metal studs for plaster partitions.
C-54 Ceramic and Mosaic Tile. Glazed wall, ceramic, mosaic, quarry, paver, glass mosaic, and stone tile.

Specialty Trades

C-22 Asbestos Abatement. Asbestos containment, encapsulation, removal, and disposal. Stand-alone classification required for asbestos work regardless of any other licenses held. Must be DOSH-registered.
C-28 Lock and Security Equipment. Locks, exit devices, electronic access control, motion detectors, built-in safes, and vaults. Not fire alarms.
C-45 Sign. Electrical signs (including wiring) and non-electrical signs.
C-47 General Manufactured Housing. Manufactured, mobile, and multifamily manufactured homes, foundations, accessory buildings, and utility connections on single-family sites.
C-53 Swimming Pool. Swimming pools, spas, and hot tubs, including incidental solar heating.
C-60 Welding. Permanent metal joining via gases or electrical heat.

C-61 Limited Specialty

C-61 covers specialty work outside the named C classifications. CSLB tracks C-61 licenses by "D" subcategory codes. A C-61 contractor must confine work to the specific D-field on their certificate.

Active D subcategories include: D-03 Awnings, D-04 Central Vacuum Systems, D-06 Concrete-Related Services (sawing, gunite, post-tensioning, pumping), D-09 Drilling/Blasting/Oil Field (no water-well drilling), D-10 Elevated Floors, D-12 Synthetic Products, D-16 Hardware/Locks/Safes, D-21 Machinery and Pumps, D-24 Metal Products, D-28 Doors/Gates/Activating Devices, D-29 Paperhanging, D-30 Pile Driving/Pressure Foundation Jacking, D-31 Pole Installation, D-34 Prefabricated Equipment, D-35 Pool and Spa Maintenance, D-38 Sand and Water Blasting, D-39 Scaffolding, D-40 Service Station Equipment, D-41 Siding and Decking, D-42 Non-Electrical Sign Installation, D-50 Suspended Ceilings, D-52 Window Coverings, D-53 Wood Tanks, D-56 Trenching, D-59 Hydroseed Spraying, D-62 Air and Water Balancing, D-63 Construction Cleanup, D-64 Non-Specialized, D-65 Weatherization and Energy Conservation.

CSLB no longer issues new licenses in many older D subcategories (D-05, D-07, D-08, D-13, D-17, D-19, D-20, D-22, D-23, D-25, D-27, D-32, D-33, D-36, D-37, D-43 through D-49, D-51, D-54, D-55, D-58, D-60). Most have been folded into existing C classifications.

Special Certifications and Solar

ASB (Asbestos Certification). Authorizes asbestos work within a contractor's existing classification(s). C-22 is the standalone abatement classification and operates independently regardless of other licenses held.

HAZ (Hazardous Substance Removal Certification). Required for hazardous substance removal. Issued only to contractors who already hold an A, B, C-12, C-21, C-36, C-57, or C-61/D-40 license. Both certifications require a separate application and exam.

Solar work: which licenses qualify. Only A, B, C-4, C-10, C-36, C-46, and C-53 are authorized to perform solar work. Specifically: A for solar requiring specialized engineering; B for active solar energy projects; C-4 for solar heating within its system scope; C-10 for all electrical and PV solar; C-36 for solar water and fluid heating; C-46 for thermal and PV solar (solar only — no other trades); and C-53 for solar pool heating. If your classification is not on this list, you cannot perform solar work.

Common Questions: Can I Do This With My License?

Can a Class B contractor do plumbing? Not by self-performing it. On a qualifying multi-trade project, the B contractor must subcontract plumbing to a licensed C-36. To self-perform plumbing, add the C-36 classification to your B license.

Can a Class B contractor do roofing? Only as part of a project involving at least one other unrelated trade. A B contractor cannot take a standalone roofing contract or a roofing-only subcontract without a C-39 Roofing license.

Can a B-2 contractor do structural work on a small house? No. B-2 is strictly nonstructural. Any work on load-bearing walls, footings, foundations, or roof structures requires a full Class B license, regardless of project size.

Can a C-46 Solar contractor do roofing as part of a solar job? Only to the extent strictly required to install the solar system. The C-46 scope is limited to solar installation — it does not authorize general roofing work.

Can a Class B contractor take a standalone fencing contract? No. Standalone fencing requires a C-13 Fencing license. A B contractor can include fencing in a larger multi-trade project.

Can I hire subcontractors under an independent contractor arrangement? This depends on California's ABC test under AB5. In most construction scenarios, workers who are not licensed subcontractors must be treated as employees. See the Independent Contractor vs. Employee (AB5) guide for details.

California AB 2622: The New $1,000 Licensing Threshold

Effective January 1, 2025, Assembly Bill 2622 raised the unlicensed-work exemption from $500 to $1,000, amending BPC §7048. The exemption applies only when all of the following are true:

The total contract price (labor, materials, and all other items) is under $1,000
No building permit is required for the work
The unlicensed person does not hire additional workers to assist
Any advertising clearly states the person is not licensed

The permit condition is easy to miss. A water heater swap might cost under $200 in materials — but if a permit is required, a contractor's license is required regardless of the dollar amount. Always check local permit requirements before assuming the exemption applies.

Penalties for unlicensed work above the threshold include misdemeanor charges, fines, and disgorgement of payments already received. Per BPC §7031, courts can order an unlicensed contractor to repay all money they received for the work, even if it was performed competently.

Key Rules That Catch Contractors Off Guard

The advertising rule. Licensees must include their license number on all advertising — business cards, vehicles, websites, and online listings. Failure to do so is a disciplinary offense.

Bond requirement. Every active license requires a $25,000 contractor's license bond. If the qualifying individual (RMO or RME) differs from the license owner, an additional $25,000 Bond of Qualifying Individual is also required.

Workers' compensation: SB 216 / SB 1455. SB 216 (2022) phased in mandatory workers' comp for all licensed contractors regardless of whether they have employees. Classifications C-8 (Concrete), C-20 (HVAC), C-22 (Asbestos), C-39 (Roofing), and C-49 (Tree and Palm) already carry mandatory workers' comp requirements under this phased rollout. SB 1455 (2024) extended the universal deadline for all remaining classifications from January 1, 2026 to January 1, 2028. If you have any employees today, you must carry workers' comp now, regardless of classification.

Initial license fees. The initial license fee for a sole owner is $200. For corporations, LLCs, and partnerships, verify the current fee directly on CSLB's fee schedule at cslb.ca.gov before applying, as fees for non-sole-owner entities differ.

Out-of-scope contracting. Working outside your classification is treated like unlicensed work. Per BPC §7031, you cannot collect through the courts and existing payments can be clawed back. Holding some California license is not a defense if it is the wrong one.

The qualifying individual. Every license has a qualifier (RME, RMO, or sole owner) who must directly supervise construction operations. Sham qualifying arrangements are a serious CSLB enforcement target. See the experience requirements guide for what "direct supervision" means in practice.

Reciprocity and Application Basics

Reciprocity with other states. California waives the trade exam (not the Law and Business exam) for license holders in good standing from Arizona, Louisiana, Nevada, and North Carolina — provided the candidate has held their out-of-state license for at least five years and applies in a corresponding California classification. CSLB will also waive the Class B trade exam for Louisiana licensees who have passed the NASCLA Commercial Building exam and held a Louisiana General Builder license for five years or more. Reciprocity does not skip the application, fingerprinting, bond, or Law and Business exam.

The application path. For a full walkthrough of every step, see the How to Apply for a California Contractor License guide. In brief: document four years of journey-level experience, submit the $450 application, complete Live Scan fingerprinting ($49 to $59), wait 4 to 6 weeks for processing, pass both exams, post the $25,000 bond, and pay the initial license fee. Total upfront costs typically run $1,500 to $3,000 including exam prep and bond premium.

Official References

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