Is a C-36 Plumbing License Worth It? What California Law Says Happens Without One

If you want to run your own plumbing jobs in California, the C-36 license is not optional, and that is the real answer to whether it is worth it. Any construction project valued at $1,000 or more in labor and materials combined must be done by a CSLB-licensed contractor, and a license is required no matter the price if the work needs a permit or you have workers. Without one, contracting is a misdemeanor, you cannot go to court to collect what a customer owes you, and the customer can sue to get back everything they paid you. The license costs a $450 application fee, a $200 initial license fee for a sole owner, a bond, and two exams.

So the question is not really "is it worth it." It is "do I want to work for myself." If yes, you need it.

Key facts

What the license lets you do

A C-36 plumbing contractor provides a means for a supply of safe water, ample in volume and of suitable temperature for the purpose intended, and the proper disposal of fluid waste from the premises in all structures and fixed works. That covers water and gas piping, gas appliances and connections, on-site waste disposal systems, and piping for gases including medical and dental gases.

With the license you can contract for that work directly, at any size, under your own name.

The $1,000 line, and why "small jobs only" does not work

The law exempts work where the aggregate contract price for labor, materials, and all other items is less than one thousand dollars ($1,000), if the work is casual, minor, or inconsequential and does not require a building permit. But the exemption disappears if:

• the job is part of a larger operation, or is split into contracts under $1,000 to get around the law,
• you advertise or put out a sign or card that suggests you are a contractor, or
• you employ another person to perform or help with the work.

In other words: the moment you advertise, hire a helper, or take a job that needs a permit, you need the license, whatever the price.

What working without one costs

• It is a crime. Contracting without a license is a misdemeanor. A first conviction is punishable by a fine not exceeding five thousand dollars ($5,000), up to six months in county jail, or both. Penalties climb on a second conviction.
• You cannot collect. An unlicensed contractor cannot bring or maintain any action in a California court to collect compensation for work that requires a license, regardless of the merits.
• You can be made to pay it all back. A person who uses an unlicensed contractor may sue to recover all compensation paid for the work.

That last one is the one that ruins people. The customer keeps the plumbing and gets the money back.

What it takes to get

• Experience: four years of at least journey-level work in the last 10 years.
• Money: a $450 application fee, exam fees paid to PSI, fingerprinting, a $200 initial license fee for a sole owner ($350 for a non-sole owner), and a $25,000 bond or cashier's check.
• Exams: two closed-book exams, the C-36 trade exam and Law and Business, with 3½ hours for each.

Every step is in how to get a C-36 license, and every fee is in how much a C-36 license costs.

What about income?

We do not publish wage numbers we cannot prove. For current pay data, the official source is the U.S. Bureau of Labor Statistics' Occupational Employment and Wage Statistics for Plumbers, Pipefitters, and Steamfitters, which reports national, state and metro-area wages. What the license changes is not your hourly rate as an employee; it is whether you can legally contract your own jobs and keep the business.

Common questions

Do I need a C-36 license to do plumbing in California?

You need it to contract plumbing work valued at $1,000 or more in labor and materials, or any job that needs a permit or workers. Below that, the exemption is lost if you advertise as a contractor or employ anyone.

What happens if I do plumbing work without a license?

Contracting without a license is a misdemeanor; a first conviction can mean a fine up to $5,000, up to six months in county jail, or both. You also cannot sue to collect what you are owed, and your customer can sue to recover everything they paid you.

How much does it cost to get a C-36 license?

A $450 application fee and a $200 initial license fee for a sole owner, plus exam fees paid to PSI, fingerprinting, and a $25,000 bond or cashier's check.

Is the C-36 exam hard?

It is two closed-book exams with four choices per question and one BEST answer, and CSLB does not publish a passing percentage. See how hard the C-36 is.

Sources

• California Business and Professions Code: Contractors State License Law
• CSLB, Get Licensed to Build
• CSLB, Description of Classifications
• U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics

_Last reviewed: 2026-10-15. Every fact above is quoted from the law or CSLB document it cites and checked by code against our stored copy of that document._

If you are going to do it, pass it once

Take the free 21-question C-36 diagnostic to see, topic by topic, where you would lose points today. No account needed. The full course is $148.75 one time: lessons for both exams, practice questions with written explanations, and timed practice exams, in English and Spanish. See what is included.