Types of General Contractor License, Explained
Most states split contractor licensing into two broad tiers: a general classification that covers projects requiring multiple unrelated trades, and dozens of specialty classifications that each cover one specific trade, like electrical, HVAC, or roofing. California’s CSLB runs the clearest, most granular public version of this system, using an A/B/C letter code that other states’ systems parallel without matching exactly.
Understanding which tier you need matters before you study for an exam, since the trade exam you sit is entirely determined by the classification you’re applying for. Picking the wrong classification means studying the wrong material and, in some states, paying application fees twice.
What does “General Engineering” (A) actually cover?
Fixed works of engineering character: highways, dams, bridges, utility systems, and similar projects that aren’t buildings in the ordinary sense. This is CSLB’s Class A classification, and it’s the category most associated with heavy civil and infrastructure work rather than buildings people live or work in.
What does “General Building” (B) actually cover?
Any structure built for the support, shelter, or enclosure of people, animals, or property, as long as the job requires at least two unrelated building trades or crafts. That “two unrelated trades” test is the legal core of the B classification under California law (Business and Professions Code Section 7057): a B contractor generally can’t take a prime contract limited to a single specialty trade unless framing or carpentry is involved, since those two are treated as an exception.
A B contractor can always take a prime or subcontract for framing or carpentry work alone. For any other single trade, the B license only applies if the contract requires at least two unrelated trades beyond framing/carpentry, or the contractor also holds (or subcontracts to) the specific specialty license needed. Our general contractor b license page covers this rule in more depth, including the specific carve-outs for fire protection and well drilling work.
What are the “C” specialty classifications?
Roughly 40 separate trade-specific licenses under California’s system, each covering one narrow scope of work: C-10 Electrical, C-20 Warm-Air Heating/Ventilating/Air-Conditioning, C-36 Plumbing, C-39 Roofing, and dozens more down to niche categories like C-61 Limited Specialty. Each carries its own trade exam and its own study guide published directly by CSLB (CSLB Licensing Classifications).
| Classification code | Trade |
|---|---|
| C-10 | Electrical |
| C-20 | Warm-air heating, ventilating, air-conditioning |
| C-36 | Plumbing |
| C-39 | Roofing |
| C-8 | Concrete |
| C-27 | Landscaping |
| C-61 | Limited Specialty (no trade exam required) |
A specialty contractor is licensed only for the scope described in their specific classification. A C-10 electrical contractor can’t take on plumbing work under that same license; they’d need a separate C-36, or they’d need to subcontract that scope to a licensed plumber.
How do other states’ classification systems compare?
They cover the same underlying idea (general/broad-scope licenses versus narrow trade licenses) but organize it differently. Florida splits licensure into Division 1 (General, Building, Residential Contractors, tested on a three-part exam) and Division 2 (specific specialty categories like Roofing, Mechanical, or Plumbing, tested on a two-part exam). Georgia splits by Residential versus General (commercial) division rather than by trade granularity. Arizona uses a Commercial/Residential/Dual scope system layered with its own classification codes (B, B-1, B-2, C, R, and more).
North Carolina takes a different approach entirely, licensing by broad category (Building, Residential, Highway, Public Utilities, Specialty) combined with project-value tiers, so the “type” of license there is as much about how large a job you can take as what trade you’re licensed for.
Do I need the general classification, or just a specialty one?
It depends on what you actually plan to build. If your work regularly spans multiple trades on one job (a full remodel involving framing, electrical, and plumbing coordination, for instance), a general classification like CSLB’s B is the more practical fit, since it lets you take the prime contract and coordinate subcontractors under one license. If you only ever perform one specific trade, a specialty classification is usually the faster and cheaper path, since it requires one trade exam instead of qualifying under the broader “two unrelated trades” test.
Our class a general contractor license and general contractor b license pages go deeper on California’s two general classifications specifically. For the highest-volume specialty trades in our research, see electrical contractor license, hvac contractor license, and roofing contractor license.
Can I hold more than one classification?
Yes, in every state we researched. CSLB, for example, lets you add classifications to an existing license for a per-classification fee ($230 for an existing license, per CSLB’s current fee schedule), provided you meet the experience and exam requirements for each one separately. Many working contractors hold a general classification plus one or two specialty classifications relevant to their most common subcontracted scopes.
Does the classification affect my bond or insurance requirement?
Sometimes. California’s bond requirement is flat at $25,000 regardless of classification, but other states scale bonding by classification or license scope; Arizona, for example, requires substantially different bond amounts across its Commercial, Residential, and Dual scopes. See our general contractor license bond guide for how that variation plays out state by state.
Run a diagnostic round on our free contractor license practice quiz to test your classification knowledge before you commit to studying one specific trade exam, and grab the GC License Hub Exam Prep Cheat Sheet for the full classification list on one printable page.
FAQ
What’s the difference between Class A and Class B? Class A (General Engineering) covers fixed civil-engineering works like highways and dams; Class B (General Building) covers structures for people, animals, or property, provided at least two unrelated trades are involved.
Do all states use the letter-code A/B/C system? No, that specific coding is California’s CSLB system. Other states organize licenses by division (Florida), by residential/general split (Georgia), by scope (Arizona), or by project value tier (North Carolina), even though the underlying general-versus-specialty concept is similar.
Which classification is the most common for a general remodeling contractor? Typically the general building classification (California’s Class B or its equivalent elsewhere), since remodeling work usually spans more than one trade.
Is a specialty license cheaper to get than a general license? Often the application and exam process is similar in cost, but a specialty classification typically requires studying one narrower trade exam instead of qualifying under a broader multi-trade test, which can shorten prep time.
Can I upgrade from a specialty license to a general one later? Yes, in the states we researched, this typically means applying for the additional classification and meeting its specific experience and exam requirements, not converting your existing license.
Bottom line: nearly every state splits contractor licensing into a broad general classification and narrower trade-specific specialty classifications, though the exact coding and structure vary. Pick the classification that matches your actual scope of work before you commit study time to one specific trade exam.
