---
title: "C-10 vs C-7 vs C-45: Which California Electrical License Do You Need?"
description: "C-10, C-7, or C-45? Compare California electrical license classifications side by side, see where the B general contractor overlaps, and pick the right one."
url: https://caelectricalprep.com/blog/c10-vs-c7-vs-c45-which-electrical-license
published: 2026-08-17
topic: "Licensing"
language: en
license: "Free to read and quote with attribution to CA Electrical Prep (https://caelectricalprep.com)."
source_of_truth: "2025 California Electrical Code (Title 24, Part 3), which adopts the 2023 NEC with California amendments."
---

# C-10 vs C-7 vs C-45: Which California Electrical License Do You Need?

C-10, C-7, or C-45? Compare California electrical license classifications side by side, see where the B general contractor overlaps, and pick the right one.

## Key points

- The C-10 Electrical is the broad classification: it covers electrical systems generally, which is why it is the one most electrical businesses apply for.
- The C-7 Low Voltage Systems classification is built around communication and low-energy signal work, not general power wiring.
- The C-45 Sign classification is for electrical signs and their supporting structures and circuits, and it is far narrower than the C-10.
- A B General Building contractor can take projects involving multiple trades, but that does not turn a B into a substitute for a specialty electrical license on standalone electrical jobs.
- Pick the classification that matches the work you actually sell, then confirm the exact current scope language and fees directly with the CSLB at cslb.ca.gov.

Most people searching for a California electrical contractor license land on the C-10 and never look further. That is usually correct, but not always. California licenses contractors by classification, and there are three that touch electrical work directly plus one general classification that keeps showing up in the confusion.

Here is how they actually differ, and how to figure out which one belongs on your application.

## The short version

- **C-10 Electrical** — the broad electrical classification. Power wiring, distribution, devices, equipment. This is the default for an electrical contracting business.
- **C-7 Low Voltage Systems** — communication and signal systems. Data, telephone, sound, intercom, some alarm and control work.
- **C-45 Sign** — electrical signs: the sign itself, its supports, and the electrical work that feeds it.
- **B General Building** — not an electrical classification at all, but it comes up constantly because generals run projects that include electrical work.

## Scope comparison

| | C-10 Electrical | C-7 Low Voltage Systems | C-45 Sign |
|---|---|---|---|
| Core focus | Electrical systems generally: generation, transmission, distribution, utilization | Communication, signal, and low-energy systems | Electrical signs and their supporting structures |
| Typical work | Service upgrades, panels, branch circuits, feeders, lighting, motor circuits, EV charging, commercial and industrial power | Structured cabling, telephone and data, sound and intercom, certain alarm and control systems | Channel letters, pylon and monument signs, illuminated cabinets, sign supply circuits and disconnects |
| Trade exam content | Broad NEC-based electrical: load calcs, ampacity, overcurrent, grounding and bonding, boxes and raceways, motors and transformers | Low voltage and communication systems focus | Sign fabrication, erection, and the electrical work supplying signs |
| Who it fits | Anyone selling electrical work as their business | A company that only does comm and signal work and does not want the full electrical exam | A sign shop that builds, installs, and services signs |
| Law and Business exam | Required | Required | Required |
| Four-year experience requirement | Required | Required | Required |

All three specialty classifications sit on the same foundation: journey-level or higher experience in the classification you are applying for, the Law and Business exam, the trade exam, a contractor bond, and a workers compensation policy if you have employees. Read the [full C-10 requirements](/blog/c10-license-requirements-california) for how that experience is documented and certified.

## When the C-10 is obviously the answer

If you are wiring services, pulling feeders, setting panels, running branch circuits, installing lighting, terminating motor circuits, or doing EV charger installs, you want the C-10. It is written broadly enough to cover the electrical systems side of a normal electrical contracting business, and it is the classification building departments and general contractors expect to see on an electrical sub.

The trade exam reflects that breadth. Expect real calculation work — [load calculations](/blog/electrical-load-calculations-c10), [conductor ampacity and sizing](/blog/conductor-ampacity-and-sizing-c10), [overcurrent protection](/blog/overcurrent-protection-c10), and [grounding and bonding](/blog/grounding-and-bonding-c10-exam) all carry weight. Trade content is governed by the 2025 California Electrical Code, which adopts the 2023 NEC with California amendments, so study from the California edition rather than a plain NEC.

## When the C-7 makes more sense

The C-7 exists for companies whose entire business is low-energy signal work. If you install structured cabling, phone and data systems, sound and intercom, nurse call, or similar communication systems — and you have no intention of touching general power wiring — the C-7 is a shorter path to a license that matches what you sell.

The trap is growth. Plenty of low voltage companies eventually get asked to add a circuit, move a panel, or provide power to the equipment they just installed. At that point you either sub it out to a C-10 or you go get the C-10 yourself. If you can already see that coming, sitting for the broader exam once is usually cheaper than doing it twice.

One thing that trips people up: contractor licensing and electrician certification are two separate systems in California. The CSLB licenses the business; the Division of Labor Standards Enforcement certifies individual electricians who work for C-10 contractors. That distinction is worth understanding before you plan a career path — see [contractor license vs electrician certification](/blog/c10-license-vs-electrician-certification).

## When the C-45 is the right call

The C-45 Sign classification is genuinely specialized. Sign work is a package deal: the cabinet or channel letters, the structural support and mounting, and the electrical supply, disconnect, and internal wiring. A shop that fabricates and erects signs is doing structural and electrical work at the same time, and the C-45 is scoped for exactly that combination.

If signs are your business, the C-45 is the efficient license. If signs are one line item inside a broader electrical company, the C-10 is likely the better fit — but confirm the current scope language with the CSLB rather than relying on a summary, including this one.

## Where the B general contractor fits

The B General Building classification covers projects that require at least two unrelated building trades — the classic ground-up or full-remodel job. A B typically subcontracts the electrical scope to a licensed electrical contractor.

What the B does not do is act as a workaround. A general contractor cannot simply decide to take standalone electrical jobs because they hold a B. If electrical work is what you are selling, the electrical classification is what you need. The line between "project involving multiple trades" and "electrical job" is exactly the kind of thing CSLB enforcement looks at, so if you are near it, ask before you bid. Our overview of [when a license is required for electrical work](/blog/do-i-need-license-electrical-work-california) walks through the practical boundaries.

## Can you hold more than one?

Yes. Contractors add classifications to an existing license routinely — a C-10 holder who starts doing significant sign volume can pursue the C-45, and vice versa. Each added classification generally requires its own trade exam and its own qualifying experience, though the Law and Business exam is not something you retake for every classification once you have passed it. Application fees, renewal timing, and exam scheduling change from time to time, so verify the current numbers and process on cslb.ca.gov before you budget.

## How to decide

Ask one question: **what will you put on a customer invoice?**

- Electrical systems and power work → C-10
- Communication and signal systems only → C-7
- Signs, start to finish → C-45
- Multi-trade construction projects where electrical is a sub → B, with a licensed electrical sub

If the honest answer is "mostly one, sometimes the other," lean toward the broader classification and sub out the edges. It is easier to narrow your work than to turn down a job you are not licensed for.

## Then comes the exam

Whichever classification you pick, the licensing path ends the same way: two exams, both of which people underestimate. The [Law and Business exam](/blog/law-and-business-exam-guide) catches contractors who assume years in the field will carry them, and the trade exam rewards people who have done the calculations under time pressure rather than just read about them.

The single most reliable predictor of passing is not how many hours you studied — it is whether you have worked enough timed practice questions to know your pace and to recognize where you are still guessing. Build that habit early, and exam day stops being a mystery. If you want a structured start, our [C-10 study guide](/blog/c10-electrical-exam-study-guide) lays out a workable sequence.

## Questions and answers

### Can I do low voltage work with a C-10 license?

In practice, the C-10 Electrical classification is written broadly around electrical systems, and most contractors treat low voltage installations as falling inside that scope. The C-7 exists because many companies only do communication and signal work and do not want to sit for the full electrical trade exam. Because scope disputes are decided against the exact regulation text, read the current C-10 and C-7 scope language on cslb.ca.gov before bidding anything that sits near the line.

### Do I need a separate license for electrical signs if I already hold a C-10?

The C-45 Sign classification exists as its own specialty because sign work involves the sign structure, mounting, and its electrical supply as a package. If your business is primarily fabricating, erecting, and servicing electrical signs, the C-45 is the classification built for that work. If signs are an occasional part of a broader electrical business, ask CSLB directly how your specific project scope is treated rather than assuming.

### Is the C-7 exam easier than the C-10 exam?

They are different exams with different content outlines, not simply an easy version and a hard version. The C-10 trade exam covers the breadth of electrical work, including load calculations, conductor sizing, overcurrent protection, grounding and bonding, and motors and transformers. The C-7 exam concentrates on low voltage and communication systems. Neither is a formality, and both sit on top of the same four-year journey-level experience requirement and the Law and Business exam.

### Can a B General Building contractor hire out the electrical work?

Yes. That is the normal arrangement. A B General Building contractor running a project involving two or more unrelated trades typically subcontracts the electrical scope to a properly licensed electrical contractor. What the B classification does not do is give a general contractor a clean path to take standalone electrical jobs as if they held a C-10. If you plan to sell electrical work directly, get the electrical classification.

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