California Contractor License Types
Complete guide to all CSLB classification codes — backed by real data from 243,680 California contractor license records.
243,680
Total Licenses
232,157
Active Licenses
112
Classification Types
95%
Active Rate
Understanding CSLB License Classifications
The California Contractors State License Board (CSLB) issues licenses under three main classes: Class A (General Engineering) for infrastructure projects, Class B (General Building) for structures, and Class C (Specialty) for specific trades like electrical, plumbing, and HVAC. There are also Class D subcategories for limited specialty work under the C-61 classification.
The table below shows every classification code we found in our database of 243,680 CSLB license records, sorted by the number of active licenses. You can use this to understand how common each specialty is and where the most contractors of each type are located.
All CSLB Classification Codes
| Code | Classification Name | Active Licenses |
|---|---|---|
| B | General Building | 103,126 |
| C-10 | Electrical | 27,786 |
| C-36 | Plumbing | 17,257 |
| C-33 | Painting and Decorating | 15,439 |
| A | General Engineering | 14,779 |
| C-27 | Landscaping | 11,972 |
| C-20 | Warm-Air Heating, Ventilating and Air-Conditioning (HVAC) | 11,486 |
| C-15 | Flooring and Floor Covering | 6,811 |
| C-54 | Ceramic and Mosaic Tile | 6,155 |
| C-39 | Roofing | 5,389 |
| C-8 | Concrete | 5,293 |
| C-7 | Low Voltage Systems | 4,659 |
| C-6 | Cabinet, Millwork and Finish Carpentry | 4,262 |
| C-9 | Drywall | 3,162 |
| C-17 | Glazing | 3,028 |
| C-53 | Swimming Pool | 2,839 |
| D-49 | Tree Service | 2,778 |
| D-28 | Doors, Gates and Activating Devices | 2,745 |
| C-12 | Earthwork and Paving | 2,417 |
| C-16 | Fire Protection | 2,184 |
| C-29 | Masonry | 2,067 |
| C-21 | Building Moving/Demolition | 1,802 |
| C-35 | Lathing and Plastering | 1,798 |
| HAZ | Hazardous Substance Removal | 1,796 |
| C-13 | Fencing | 1,793 |
| D-12 | Synthetic Products | 1,731 |
| D-35 | Pool and Spa Maintenance | 1,631 |
| C-38 | Refrigeration | 1,621 |
| C-51 | Structural Steel | 1,505 |
| D-52 | Window Coverings | 1,472 |
| D-06 | Specialty | 1,465 |
| B-2 | Specialty | 1,454 |
| D-34 | Prefabricated Equipment | 1,368 |
| C-43 | Sheet Metal | 1,288 |
| C-46 | Solar | 1,187 |
| C-2 | Insulation and Acoustical | 1,168 |
| C-60 | Welding | 1,068 |
| C-23 | Ornamental Metal | 1,063 |
| D-21 | Machinery and Pumps | 1,050 |
| C-5 | Framing and Rough Carpentry | 1,017 |
| C-42 | Sanitation System | 947 |
| D-63 | Construction Clean-Up | 855 |
| C-45 | Electrical Sign | 845 |
| D-24 | Metal Products | 808 |
| ASB | Asbestos Certification | 790 |
| C-57 | Well Drilling | 717 |
| C-4 | Boiler, Hot Water Heating and Steam Fitting | 683 |
| D-64 | Non-Specializing Owner-Builder | 628 |
| C-34 | Pipeline | 530 |
| D-03 | Specialty | 527 |
| C-32 | Parking and Highway Improvement | 502 |
| C-49 | Specialty | 469 |
| C-47 | General Manufactured Housing | 450 |
| C-31 | Construction Zone Traffic Control | 447 |
| D-42 | Non-Electrical Sign Installation | 415 |
| D-38 | Sand and Water Blasting | 413 |
| D-41 | Siding and Decking | 397 |
| C-28 | Lock and Security Equipment | 363 |
| C-22 | Asbestos Abatement | 310 |
| C-55 | Water Conditioning | 300 |
| D-39 | Scaffolding | 278 |
| D-16 | Hardware, Locks and Safes | 273 |
| C-50 | Reinforcing Steel | 256 |
| C-11 | Elevator | 215 |
| D-29 | Paperhanging | 175 |
| D-56 | Trenching | 167 |
| D-09 | Specialty | 156 |
| D-50 | Suspended Ceilings | 141 |
| D-40 | Service Station Equipment and Maintenance | 140 |
| D-62 | Air and Water Balancing | 115 |
| D-30 | Pile Driving and Pressure Foundation Jacking | 85 |
| D-31 | Pole Installation and Maintenance | 81 |
| D-04 | Specialty | 77 |
| D-65 | Weatherization and Energy Conservation | 75 |
| D-51 | Specialty | 50 |
| D-59 | Specialty | 49 |
| D-10 | Elevated Floors | 23 |
| D-08 | Specialty | 18 |
| D-53 | Specialty | 17 |
| D-22 | Specialty | 12 |
| D-48 | Specialty | 11 |
| D-07 | Specialty | 9 |
| D-36 | Specialty | 5 |
| D-47 | Specialty | 5 |
| D-25 | Specialty | 4 |
| D-43 | Specialty | 3 |
| D-17 | Specialty | 3 |
| D-27 | Specialty | 3 |
| D-23 | Specialty | 3 |
| D-44 | Specialty | 3 |
| D-20 | Specialty | 2 |
| D-32 | Specialty | 1 |
| D-13 | Specialty | 1 |
| D-15 | Specialty | 1 |
| D-05 | Specialty | 1 |
| D-19 | Specialty | 1 |
| D-55 | Specialty | 1 |
| D-54 | Specialty | 1 |
| D-37 | Specialty | 1 |
| O/L ENTITY PENDING | Specialty | 0 |
| WC SUSP PENDING | Specialty | 0 |
| CLEAR | Specialty | 0 |
| FAM SUP TMP LIC | Specialty | 0 |
| RENEWAL RECIVED | Specialty | 0 |
| ENTITY SUSP PND | Specialty | 0 |
| WORK COMP SUSP | Specialty | 0 |
| PENDING IFS | Specialty | 0 |
| BOND PAY ENTITY PENDING | Specialty | 0 |
| 7073E PROBATION | Specialty | 0 |
| PENDING CASE/CIT | Specialty | 0 |
| LIABILITY PEND | Specialty | 0 |
| JUDGEMENT PEND | Specialty | 0 |
Most Popular License Types
1
B
General Building
Active Licenses 103,126
Total Licenses 107,423
Top City Los Angeles
2
C-10
Electrical
Active Licenses 27,786
Total Licenses 28,802
Top City Los Angeles
3
C-36
Plumbing
Active Licenses 17,257
Total Licenses 17,936
Top City Los Angeles
Frequently Asked Questions
What are the different types of contractor licenses in California? +
California issues three main categories of contractor licenses through the CSLB: Class A (General Engineering), Class B (General Building), and Class C (Specialty). Class C licenses are further divided into over 40 specialty classifications like C-10 (Electrical), C-36 (Plumbing), and C-20 (HVAC). There are also Class D subcategories for limited specialty work. In total, CSLB recognizes 112 distinct classification codes.
What is a Class B contractor license in California? +
A Class B license is a General Building contractor license. It allows contractors to build, alter, or repair structures like homes, commercial buildings, and other improvements. With 103,126 active licenses, it is the most common contractor license type in California. Class B contractors can perform work that involves two or more unrelated building trades, but they cannot take on projects that require a Class A (General Engineering) license.
What is a C-10 license in California? +
A C-10 license is for Electrical contractors in California. It authorizes the installation, alteration, and repair of electrical systems including power, lighting, and appliance wiring. With 27,786 active licenses, it is the most common specialty (Class C) license in the state. C-10 contractors must pass a specific trade exam administered by the CSLB.
How many licensed contractors are in California? +
California has approximately 232,157 active licensed contractors as of our latest data analysis, out of 243,680 total license records maintained by the Contractors State License Board (CSLB). The most common license type is Class B (General Building), followed by C-10 (Electrical) and C-36 (Plumbing).
What is the most common contractor license type in California? +
The most common contractor license type in California is the Class B (General Building) license, with 103,126 active licenses. The next most common are C-10 (Electrical) with 27,786 active licenses, C-36 (Plumbing) with 17,257, and C-33 (Painting and Decorating) with 15,439.
What is the difference between a Class A and Class B contractor license? +
A Class A (General Engineering) license covers projects that are primarily fixed works requiring specialized engineering knowledge — such as roads, bridges, dams, pipelines, and utilities. A Class B (General Building) license covers projects involving structures like homes, offices, and commercial buildings. Class A work is typically infrastructure-related, while Class B work is building-related. A contractor must hold the specific class required for their project scope.
Do I need a specialty license for specific trades in California? +
Yes. In California, specialty work like electrical (C-10), plumbing (C-36), HVAC (C-20), and roofing (C-39) each require their own Class C specialty license. A Class B (General Building) contractor can supervise an overall building project but must subcontract specialty work to properly licensed C-class contractors, or hold those classifications themselves. Working outside your license classification can result in disciplinary action from the CSLB.
Data source: Based on analysis of 243,680 California contractor licenses from CSLB public records. Last analyzed: April 3, 2026. Classification names follow official CSLB designations.