📘 Chapter 2
License Types & Classifications
🎯 Chapter Overview
Understanding California's contractor license classifications is crucial to choosing the right path for your business. This chapter provides an in-depth exploration of the three-tier licensing system and helps you determine which license best matches your experience, skills, and business goals.
What You'll Learn in This Chapter:
- Detailed breakdown of Class A, B, and C license classifications
- Scope of work for each classification type
- Popular specialty classifications and their requirements
- Project size limitations and their business implications
- How to choose the right classification for your career goals
- Exam difficulty levels and pass rates by classification
- Strategic considerations for adding multiple classifications
🏗️ California's Three-Tier License System
California organizes contractor licenses into three main classifications, each with distinct scopes of work, project limitations, and business applications. Understanding these differences is essential before you invest time and money into the licensing process.
Class A - General Engineering Contractor
Class A contractors specialize in projects that require specialized engineering knowledge and skill. These are typically infrastructure and public works projects.
Scope of Work
- Fixed works in construction or operation, alteration, or repair
- Roads, highways, and bridges
- Sewer and water systems
- Utility installations (power, gas, communication lines)
- Dams and reservoirs
- Large-scale grading and excavation
- Marine construction (piers, wharves)
- Refineries and industrial facilities
Project Size Limits
No limit - Class A contractors can bid on projects of any size.
Who Should Consider Class A?
This classification is ideal for contractors with heavy civil construction experience who want to work on:
- Public works projects (government contracts)
- Infrastructure development
- Large-scale commercial and industrial facilities
- Utility construction projects
💡 Key Insight: Class A licenses are less common than Class B or C licenses. Many Class A contractors work extensively with government agencies and must understand prevailing wage laws and public contract code requirements.
Class B - General Building Contractor
Class B is the most versatile and popular contractor license for those in the building industry. It allows you to work on any construction project involving two or more unrelated trades.
Scope of Work
- Residential construction (single-family homes, multi-family projects)
- Commercial buildings (offices, retail, restaurants)
- Remodeling and renovation projects
- Room additions and structural modifications
- New construction from ground up
- Can act as prime contractor managing all trades
- Can self-perform work or subcontract to specialists
Project Size Limits
No limit - Class B contractors can take on projects of any value.
Who Should Consider Class B?
This classification is perfect for contractors who want to:
- Build or remodel homes and commercial buildings
- Act as a general contractor managing multiple trades
- Have flexibility to work on various building projects
- Scale their business without license limitations
💡 Pro Tip: Class B is often called the "most versatile" license because it allows you to prime contract on nearly any building construction project. Many successful contracting businesses are built on Class B licenses.
Class C - Specialty Contractors
Class C licenses are for specialty trades. California offers over 40 different C classifications, each covering a specific area of construction.
Scope of Work
Specialty contractors perform work within their specific trade classification. They can work as:
- Prime contractors on projects limited to their specialty (up to $500,000 total project value)
- Subcontractors with no project size limit when working under a Class A or B contractor
Project Size Limits
$500,000 limit when acting as prime contractor. No limit when working as a subcontractor.
⚠️ Important Limitation: The $500,000 limit applies to the total project value, not just your portion of work. If you're a C-10 electrician bidding as prime contractor on a commercial build-out worth $600,000, you exceed the limit even if electrical work is only $100,000.
Who Should Consider Class C?
Specialty classifications are ideal for:
- Tradespeople with focused expertise in one area
- Contractors who primarily work as subcontractors
- Those wanting to specialize and become experts in their field
- Smaller businesses with specific market niches
🔧 Popular Specialty Classifications (Class C)
Let's explore the most common Class C specialties in detail. These classifications represent the majority of licensed contractors in California.
C-10: Electrical Contractor
C-10 contractors install, maintain, and repair electrical wiring, fixtures, and equipment.
Scope Includes:
- Installation of wiring systems and electrical panels
- Low-voltage systems (fire alarms, security, data)
- Residential and commercial electrical work
- Service upgrades and panel replacements
- Lighting installation (indoor and outdoor)
- Generator installation and hookup
- Electric vehicle charging stations
Code Requirements:
Must work in compliance with the National Electrical Code (NEC) and California Electrical Code.
Exam Difficulty:
C-10 has one of the more challenging trade exams (pass rate around 45-55%) due to extensive code knowledge and calculations required.
Market Opportunity: Electrical contractors are in high demand, especially those qualified for solar integration, EV charging, and smart home systems. The shift to electric vehicles and renewable energy creates strong growth opportunities.
C-20: Warm-Air Heating, Ventilating and Air-Conditioning
C-20 contractors install and service HVAC systems for climate control.
Scope Includes:
- Installation of heating and cooling systems
- Ductwork fabrication and installation
- Air filtration and ventilation systems
- Refrigeration systems
- Energy management systems
- Indoor air quality equipment
Additional Requirements:
C-20 contractors who handle refrigerants must obtain EPA Section 608 Certification. This federal certification is separate from the CSLB license.
Exam Difficulty:
Moderate difficulty (pass rate around 50-60%). Requires understanding of psychrometrics, load calculations, and mechanical codes.
💡 Business Advantage: HVAC is an essential service with year-round demand. Maintenance contracts provide steady recurring revenue, and energy efficiency upgrades are increasingly incentivized by utilities and government programs.
C-27: Landscaping Contractor
C-27 contractors perform landscape construction including irrigation, grading, and hardscape features.
Scope Includes:
- Landscape installation (plants, sod, trees)
- Irrigation systems (sprinklers, drip systems)
- Grading and drainage
- Retaining walls and hardscape
- Outdoor lighting (low voltage)
- Artificial turf installation
- Water features and fountains
- Outdoor structures (arbors, trellises, decks)
Scope Exclusions:
C-27 does not include tree trimming/removal (requires separate tree service license) or electrical work beyond low-voltage landscape lighting.
Exam Difficulty:
Moderate (pass rate around 55-65%). Covers plant identification, irrigation design, grading, and pest management.
Market Opportunity: California's drought concerns and water conservation requirements create demand for drought-tolerant landscaping, efficient irrigation systems, and synthetic turf installation. Commercial property management companies regularly need licensed landscape contractors.
C-36: Plumbing Contractor
C-36 contractors install, maintain, and repair plumbing systems and fixtures.
Scope Includes:
- Water supply piping and fixtures
- Drain, waste, and vent systems
- Gas piping (natural gas and propane)
- Water heaters and boilers
- Backflow prevention devices
- Medical gas systems
- Fire sprinkler connection to plumbing
Code Requirements:
Must comply with California Plumbing Code (CPC) and local amendments.
Exam Difficulty:
Moderate to high difficulty (pass rate around 50-60%). Heavy emphasis on code knowledge, calculations, and system design.
⚠️ Important Note: Gas piping work is within C-36 scope, but many contractors also maintain relationships with utility companies and must understand gas safety protocols. Some municipalities have additional gas piping certification requirements.
C-8: Concrete Contractor
C-8 contractors specialize in concrete and masonry construction.
Scope Includes:
- Concrete foundations and slabs
- Concrete flatwork (driveways, patios, sidewalks)
- Structural concrete (beams, columns, walls)
- Decorative concrete and stamping
- Concrete repair and restoration
- Masonry (brick, block, stone)
Exam Difficulty:
Moderate (pass rate around 55-65%). Covers mix design, forming, reinforcement, and concrete technology.
💡 Business Insight: Concrete work offers good profit margins and is fundamental to most construction projects. Specializing in decorative concrete or structural work can provide market differentiation.
C-61: Limited Specialty Contractor
C-61 is unique because it includes multiple sub-classifications for specialized trades that don't fit other categories.
Common C-61 Sub-Classifications:
- D-03: Overhead Door Installation
- D-04: Awnings and Louvres
- D-06: Low Voltage Systems (security, data, audio/video)
- D-07: Ornamental Metal
- D-12: Fence and Railings
- D-28: Ductwork
- D-34: Residential Appliance Installation
- D-49: Tree Service (requires additional ISA certification)
Important: Each D-sub-classification under C-61 requires meeting specific experience requirements and passing an exam related to that specialty. You can hold multiple D-classifications on one C-61 license.
C-46: Solar Contractor
C-46 contractors design and install solar energy systems.
Scope Includes:
- Photovoltaic (PV) solar panel installation
- Solar thermal systems
- Battery energy storage systems
- System design and engineering
- Roof attachments and penetrations (for solar)
Important Coordination:
C-46 contractors often work alongside C-10 electricians for the electrical interconnection. Some contractors hold both C-46 and C-10 classifications.
Exam Difficulty:
Moderate (pass rate around 55-65%). Covers solar technology, system design, and relevant codes.
💡 Growth Industry: California's commitment to renewable energy and net-zero goals creates substantial opportunity in solar. State incentives and utility rebates drive residential and commercial demand.
📊 Choosing the Right Classification
Selecting the appropriate license classification is one of the most important decisions in your licensing journey. The right choice opens opportunities; the wrong one creates limitations.
Key Factors to Consider
1. Your Actual Experience
You must have four years of journey-level experience in the classification you're pursuing. Be honest about your experience level.
Don't choose a classification because it "sounds good" or seems more prestigious. Choose based on what you can actually document and defend.
2. Business Model and Goals
Consider how you plan to operate:
- Prime Contractor: If you want to manage entire projects, Class B or staying under $500K with Class C
- Subcontractor: Class C specialties work well with no project size restrictions when subcontracting
- Specialized Expert: Class C allows you to build deep expertise and reputation in one trade
- Versatile Builder: Class B provides maximum flexibility across building types
3. Project Size Implications
The $500,000 limit for Class C prime contractors is based on total project value:
- If you're a specialty contractor who regularly bids on large commercial projects, the limit may restrict you
- For residential and smaller commercial work, $500K covers most projects
- Consider your growth trajectory - will you outgrow the limit in 3-5 years?
⚠️ Common Mistake: Many contractors start with a Class C license, grow their business, and then realize they need Class B to bid on larger projects. Switching later requires meeting Class B experience requirements and passing additional exams.
4. Market Demand and Competition
Research your local market:
- What types of projects are most common?
- Is there oversaturation in certain specialties?
- Are there underserved niches you can fill?
- What do general contractors in your area need?
5. Income Potential
Different classifications have varying income potential based on:
- Market rates for that trade
- Equipment and overhead costs
- Competition levels
- Difficulty in finding qualified workers
Generally, Class B contractors managing large projects have high revenue potential but also higher overhead. Class C specialists can be very profitable with lower overhead and focused expertise.
6. Multiple Classifications Strategy
Many contractors eventually hold multiple classifications. Common combinations:
- B + C-10: General building plus electrical allows self-performing more work
- B + C-36: General building plus plumbing for full-service construction
- C-20 + C-46: HVAC plus solar for integrated energy systems
- Multiple C licenses: C-27 landscaping + C-8 concrete for comprehensive outdoor construction
You can add classifications later by meeting requirements and passing additional trade exams.
Strategic Planning Questions:
- What work do I have documented experience doing?
- What work do I enjoy and want to continue doing?
- Do I want to manage projects or specialize in a trade?
- Will the $500K limit restrict my business growth?
- What classifications do my target clients require?
- Am I prepared for the exam difficulty level?
📝 Examination Requirements by Classification
All applicants take the Law & Business exam regardless of classification. The trade exam varies significantly by license type.
Law & Business Exam (All Applicants)
- Questions: 120 multiple choice
- Time: 2.5 hours
- Passing Score: 72%
- Average Pass Rate: 55-60%
Trade Exam Variations
Class A - General Engineering
- Questions: 120
- Time: 3 hours
- Pass Rate: 60-65%
- Focus: Heavy civil construction, grading, utilities, surveying
Class B - General Building
- Questions: 120
- Time: 3 hours
- Pass Rate: 60-70%
- Focus: Building codes, construction methods, project management
C-10 - Electrical
- Questions: 100
- Time: 2.5 hours
- Pass Rate: 45-55%
- Focus: National Electrical Code, calculations, system design
C-20 - HVAC
- Questions: 100
- Time: 2.5 hours
- Pass Rate: 50-60%
- Focus: Mechanical codes, load calculations, refrigeration
C-27 - Landscaping
- Questions: 100
- Time: 2.5 hours
- Pass Rate: 55-65%
- Focus: Irrigation, grading, plant science, pest management
C-36 - Plumbing
- Questions: 100
- Time: 2.5 hours
- Pass Rate: 50-60%
- Focus: California Plumbing Code, system design, calculations
Exam Preparation Tips:
- Budget study time wisely: 40-60 hours for Law & Business, 60-100 hours for trade exams
- Use code books extensively: For code-heavy exams (C-10, C-36, Class B), become intimately familiar with relevant code books
- Practice calculations: Most trade exams include math problems - practice until calculations are second nature
- Take practice exams: Identify weak areas and focus additional study there
- Consider prep courses: Professional courses significantly improve pass rates, especially for difficult exams
Exam Day Success Strategies
Regardless of your classification, follow these exam day tips:
Before the Exam
- Get a good night's sleep (don't cram the night before)
- Eat a solid meal before the exam
- Arrive 30 minutes early to settle in
- Bring approved reference materials (code books for applicable exams)
- Bring a calculator (non-programmable)
During the Exam
- Read each question carefully - don't rush
- Answer easy questions first, mark difficult ones for review
- Watch your time but don't panic
- Use your reference materials strategically
- Trust your preparation and experience
After the Exam
- Results typically available within days
- If you don't pass, review your weak areas
- You can retake exams - no mandatory waiting period (though 2-3 weeks recommended)
- Additional fees apply for retakes
📚 Chapter Review: Key Concepts
Classification System Summary
Three-Tier License Structure
- Class A (General Engineering): Infrastructure, public works, utilities, heavy construction - unlimited project size
- Class B (General Building): Building construction, remodels, commercial - unlimited project size, most versatile license
- Class C (Specialty): Over 40 specific trades - $500,000 project limit as prime contractor
Most Popular Specialty Classifications
- C-10 Electrical: Electrical systems, wiring, panels - highly technical, code-intensive exam
- C-20 HVAC: Heating, ventilation, air conditioning - strong demand, requires EPA certification for refrigerants
- C-27 Landscaping: Landscape construction, irrigation, hardscape - diverse scope, good business opportunities
- C-36 Plumbing: Plumbing systems, fixtures, gas piping - essential trade, consistent demand
- C-8 Concrete: Concrete construction, flatwork, foundations - physical work, good margins
- C-61 Limited Specialty: Various specialties including low voltage, ductwork, ornamental metal - multiple sub-classifications
Critical Decision Factors
- Match license to your actual work experience and business plans
- Consider project size limits and prime contractor vs. subcontractor role
- Evaluate market opportunities and income potential for each classification
- Plan for future business growth and multiple classifications if needed
- Verify you meet specific experience requirements before applying
- Choose based on your work, not what "sounds impressive"
Examination Success Factors
- All applicants take same Law & Business exam - 55-60% pass rate
- Trade exams vary significantly by classification - pass rates range from 45-70%
- Code-based exams (C-10, C-36, Class B) require extensive code book study
- Calculations are important for most trade exams - practice extensively
- Plan 40-60 hours for Law & Business study, 60-100 hours for trade exam study
- Professional prep courses significantly improve pass rates
✏️ Practice Questions
Test your knowledge of Chapter 2 concepts. Select the best answer for each question.
Multiple Choice
1. What is the project size limit for a C license holder acting as prime contractor?
a) $250,000
b) $500,000
c) $1,000,000
d) No limit
2. Which license classification covers complete building construction?
a) Class A
b) Class B
c) Class C
d) C-61
3. What does the C-10 license classification cover?
a) HVAC systems
b) Plumbing systems
c) Electrical systems
d) Concrete work
4. Which code book is most important for the C-36 plumbing exam?
a) National Electrical Code
b) California Plumbing Code
c) California Mechanical Code
d) California Building Code
5. What additional certification do C-20 HVAC contractors need to handle refrigerants?
a) OSHA 10
b) EPA Section 608
c) Title 24 Certification
d) Refrigeration License
6. Which classification would a landscape contractor with irrigation expertise need?
a) C-8
b) C-20
c) C-27
d) C-36
7. What is the approximate pass rate for the Law & Business exam?
a) 35-45%
b) 45-55%
c) 55-60%
d) 70-80%
8. Class A General Engineering licenses typically work on:
a) Residential home construction
b) Commercial building interiors
c) Infrastructure and public works
d) Specialty trade subcontracting
9. C-61 Limited Specialty licenses:
a) Are the easiest to obtain
b) Cover multiple sub-classifications
c) Have no project limits
d) Don't require trade exams
10. How many hours of study are recommended for trade exams?
a) 20-40 hours
b) 40-60 hours
c) 60-100 hours
d) 100-150 hours
11. Which license allows unlimited project sizes?
a) Only Class A
b) Only Class B
c) Both Class A and B
d) All license classifications
12. The C-8 license classification covers:
a) Landscaping and irrigation
b) Concrete and masonry
c) Painting and coating
d) Roofing systems
13. What is the approximate pass rate for the Class B trade exam?
a) 40-50%
b) 50-60%
c) 60-70%
d) 70-80%
14. C-61/D-06 Low Voltage Systems covers:
a) Electrical panel installation
b) Security and data systems
c) HVAC controls only
d) Solar panel wiring
15. Which is called the "most versatile" contractor license?
a) Class A
b) Class B
c) C-10
d) C-61
True/False
Mark each statement as True (T) or False (F):
✅ Answer Key
Multiple Choice Answers (Questions 1-15)
1. b) $500,000
2. b) Class B
3. c) Electrical systems
4. b) California Plumbing Code
5. b) EPA Section 608
6. c) C-27
7. c) 55-60%
8. c) Infrastructure and public works
9. b) Cover multiple sub-classifications
10. c) 60-100 hours
11. c) Both Class A and B
12. b) Concrete and masonry
13. c) 60-70%
14. b) Security and data systems
15. b) Class B
True/False Answers (Questions 16-30)
16. False - Class A is for engineering/infrastructure; Class B is for building construction
17. True - Project size limits don't apply when working as a subcontractor
18. False - Electrical work requires C-10 license; C-27 covers only landscape lighting (low voltage)
19. True - EPA certification is federally required to purchase and handle refrigerants
20. True - Class B has unlimited project size and broad building construction authority
21. False - C license holders can only prime contract within their specific classification up to $500,000
22. True - C-61 includes multiple sub-classifications like D-06, D-03, D-04, etc.
23. True - C-10 scope includes low voltage systems related to electrical work
24. False - Class A is for infrastructure and engineering projects, not building construction
25. True - You can add multiple classifications by meeting requirements and passing exams
26. False - All applicants take the same Law & Business exam
27. True - C-36 plumbing scope includes gas piping systems
28. True - $500,000 is the project limit for C contractors as prime contractor based on total project value
29. False - C-10 has one of the lower pass rates (45-55%) due to technical difficulty
30. False - Public works infrastructure requires Class A; Class B is for buildings
🔗 Additional Resources
Classification Research
- CSLB Classification List: www.cslb.ca.gov/About_Us/Library/Licensing_Classifications
- License Verification System: www.cslb.ca.gov (verify any contractor's license and classifications)
- Classification Requirements: Contact CSLB at (800) 321-2752 for specific classification questions
Exam Preparation Resources
- CSLB Exam Information: www.cslb.ca.gov/Applicants/Examinations.aspx
- Contractors License Law & Reference Book: Purchase from CSLB website
- Code Books: Available from International Code Council (ICC) and NFPA
- Professional Exam Prep Courses: Multiple providers offer classification-specific prep courses
- Practice Exams: Available from various contractors exam prep companies
Trade-Specific Resources
- National Electrical Code: www.nfpa.org (NFPA 70)
- California Building Standards Commission: www.dgs.ca.gov/bsc (access all California codes)
- Title 24 Energy Standards: www.energy.ca.gov/programs-and-topics/programs/building-energy-efficiency-standards
- EPA Section 608 Certification: www.epa.gov/section608
- Trade Associations: Join relevant associations for networking and resources
Professional Licensing Assistance
The 9th Floor LLC specializes in helping contractors navigate the classification selection process and licensing requirements. We provide personalized guidance on choosing the right license for your business, documenting experience, and preparing for examinations.
Consider Professional Assistance For:
- Evaluating which classification best fits your experience and goals
- Understanding scope limitations and business implications
- Documenting experience for complex classification requirements
- Exam preparation strategies and study planning
- Adding classifications to existing licenses
- Strategic planning for multiple classifications
🎓 End of Chapter 2
Congratulations! You've completed Chapter 2: License Types & Classifications.
You now have comprehensive knowledge about California's three-tier contractor licensing system, detailed information about the most popular specialty classifications, and strategies for choosing the right license for your business.
Next Steps:
- Review the classifications that interest you most
- Verify you have adequate experience documentation for your chosen classification
- Research market opportunities in your area for that classification
- Begin planning your exam preparation strategy
- Move on to Chapter 3 to learn about the application process
Remember: Choosing the right license classification is one of the most important decisions you'll make. Take the time to carefully evaluate your experience, business goals, and market opportunities before committing to a specific classification. The right license opens doors; the wrong one creates unnecessary limitations.
Good luck with your licensing journey!