California plumbing license requirements and insurance

To work for yourself as a plumber in California, you need the C-36 Plumbing Contractor license. The state sets no minimum liability insurance, and workers' comp is required once you have employees. A $25,000 bond is required.

Checked by the Trades by State editor on 2026-09-07 Based on 28 official pages, listed at the bottom Something wrong? Tell us

License you need: C-36 Plumbing Contractor Renew Every two years for an active license. An inactive license renews every four years
Insurance you must carry: No state minimum customers usually ask for $1,000,000
Workers' comp: Required as soon as you hire anyone
Credit score: None or take a 14-hour course
To protect your pay, send notice by: Within 20 days of your first day of work on the job (first day on January 10 means notice by January 30). A late notice still counts, but only for work done in the 20 days before you served it and after.

Turn this into a checklist

1 What stands out in California for a plumber What is this?

The things people get wrong or do not expect about California, in a few sentences.

California has one contractor license, not a journeyman, master, and business ladder. You need four years in the last ten at journey level, or as a foreman, supervising employee, contractor, or owner-builder. Then two exams, and the C-36 is issued to you or your company.
The state does not set a liability insurance minimum for a sole owner or a corporation. Only an LLC must carry it, and then the floor is $1,000,000.
Every licensee needs a $25,000 contractor bond before the license is issued. If someone other than a 10 percent owner qualifies the license, a second $25,000 bond is needed.
A plumber with no employees can still file a workers' comp exemption, but that door closes on January 1, 2028, when every licensee must carry a policy.
A C-36 plumber must show the business name, permanent business address, and license number on each side of every vehicle used in the business, in letters at least an inch and a half high. Most other trades only need the name and number, in smaller letters.
Sales tax does not care whether the job is a home or a business. You pay tax on pipe and fittings when you buy them, and you charge tax on fixtures like water heaters and sinks that you sell and install.

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·6 official pages

2 Who issues plumber licenses in California? What is this?

Contractors State License Board (CSLB), part of the California Department of Consumer Affairs issues plumbing licenses in California.

Name	Contractors State License Board (CSLB), part of the California Department of Consumer Affairs
Website	https://www.cslb.ca.gov/
Look up a license	https://www.cslb.ca.gov/OnlineServices/CheckLicenseII/CheckLicense.aspx
The law	Business and Professions Code division 3, chapter 9 (Contractors State License Law, sections 7000 and following)
The rulebook	Title 16 California Code of Regulations, division 8 (sections 810 and following)

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3 California plumber license requirements and fees What is this?

California has 1 license type that matter to a plumber. The C-36 Plumbing Contractor needs four years of work at journey level (a fully qualified worker who needs no supervision), or as a foreman, supervisor, contractor, or owner-builder, in the last ten years. Up to three of the four years can come from an apprenticeship, technical training, or a degree, but at least one year must be hands-on work. Someone who saw you do the work, such as an employer, foreman, fellow journeyman, union rep, or building inspector, must sign a Certificate of Work Experience.

C-36 Plumbing Contractor

Anyone who contracts to do plumbing work in California that needs a contractor license. A sole owner, partnership, corporation, or LLC can hold it. The license names one qualifying individual who meets the board's experience and exam requirements and is answerable for how the company does its work

What you can work on

Safe water supply and fluid waste disposal in all structures and fixed works.
Includes on-site disposal systems, piping and venting for gases and liquids (vacuum, compressed air, medical and dental gases), gas appliances, flues, and connections (not forced warm-air units).
Also water and gas piping from the utility meter to the building, and water heating equipment including solar.
Also maintenance and replacement of earthquake valves, backflow preventers, water conditioning equipment, and regulating valves.
Also underground storage tanks that serve a building.

Experience required

Four years of work at journey level (a fully qualified worker who needs no supervision), or as a foreman, supervisor, contractor, or owner-builder, in the last ten years.
Up to three of the four years can come from an apprenticeship, technical training, or a degree, but at least one year must be hands-on work.
Someone who saw you do the work, such as an employer, foreman, fellow journeyman, union rep, or building inspector, must sign a Certificate of Work Experience.

Training required

None required beyond the experience above

Exam

Yes, two computer exams run by PSI Exams: a Law and Business exam and a C-36 trade exam. You get 3.5 hours for each, 18 months from the date your application is accepted to pass both, and can retake a failed exam after 21 days.

Fees

Application	$450
Each exam (paid to PSI)	51.43
Both exams (paid to PSI)	$102.86
First license, sole owner	$200
First license, company or partnership	$350
Fingerprints (state)	32
Fingerprints (FBI)	17
Fingerprint scanning fee	Varies by location
Renewal, sole owner	$450
Renewal, company or partnership	$700
Late renewal, sole owner	$675
Late renewal, company or partnership	$1,050
Adding a license type	$230

Renewal

Every two years for an active license. An inactive license renews every four years

Training hours each year

Taken from the linked page, not separately checked

·8 official pages

4 How much insurance does a plumber need in California? What is this?

California sets no minimum liability insurance for this license. Customers and general contractors usually ask for $1,000,000 anyway. Workers' comp is required once you have employees.

Minimum liability insurance	None required by the state
Type of policy	None required by the state for a sole owner, partnership, or corporation
Minimum liability insurance for an LLC	$1,000,000
About LLC insurance	An LLC must carry liability insurance of at least $1,000,000 if it has five or fewer people on record with CSLB. Add $100,000 for each extra person, up to $5,000,000. The insurer must be licensed in California or an eligible surplus line insurer.
Who this applies to	Only licenses held by an LLC
Who must be named on the certificate	CSLB. Name the board as the certificate holder on the workers' comp certificate, and take the policy out in your licensed business name, not your own name
Workers' comp required?	Yes, as soon as you have one employee. From January 1, 2028, every licensee must carry it whether or not they have employees.
Who can opt out	Until January 1, 2028, a C-36 licensee with no employees can file a workers' comp exemption certificate with CSLB. You cannot file it if you have a Responsible Managing Employee (RME) qualifying the license. If you hire someone, the exemption stops and you have 90 days to file proof of a policy. CSLB lists no fee for the exemption.

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·7 official pages

5 Does California check your credit for a plumber license? What is this?

California does not check your credit for this license.

Credit score you need	None
If your score is lower	Nothing to do. The board does not list a credit score or a financial statement among its license requirements
About the bond	The $25,000 contractor bond is its own requirement, not a test of your finances. It protects customers if you do not finish the work

Checked by a person against the official page·cslb.ca.gov

6 Does a plumber need a bond in California? What is this?

California requires a bond of $25,000. A bond is a promise, backed by an insurance company, that customers can be paid if you do not finish the job.

Does the state require a bond?	Yes
Amount	$25,000
Bond for the qualifying person	$25,000
Bond for LLC employees	$100,000

A bond (a promise, backed by an insurance company, that customers and workers can be paid if you break the rules) of $25,000 must be on file before the license is issued, or a $25,000 cashier's check instead. If the license is qualified by a Responsible Managing Employee, or by an officer who owns less than 10 percent of the company, a second $25,000 Bond of Qualifying Individual is needed. An LLC also needs a $100,000 employee and worker bond. The bond must come from a surety licensed by the California Department of Insurance.

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·3 official pages

7 Where must a California plumber show the license number? What is this?

In California: your license number must appear in every construction contract, subcontract, and call for bid, and in every form of advertising. Advertising means business cards, contract proposals, signs, billboards, vehicle lettering, brochures, flyers, newspaper and magazine ads, radio and TV, websites, online posts, and directories.

The rule	Your license number must appear in every construction contract, subcontract, and call for bid, and in every form of advertising. Advertising means business cards, contract proposals, signs, billboards, vehicle lettering, brochures, flyers, newspaper and magazine ads, radio and TV, websites, online posts, and directories.
On your vehicles	A C-36 plumber shows three things on each side of every vehicle used in the business. The business name, the permanent business address, and the license number. Letters and numbers at least an inch and a half high. Sign contractors and well drillers follow the same rule; other trades follow the lighter one
If you forget	Leaving the number out of your advertising brings a civil penalty of $100 to $1,000 for a first offense. The vehicle rule sets no fine of its own, but the board can act against your license

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·4 official pages

8 Does a plumber charge sales tax on labor in California? What is this?

Whether California taxes your labor, your materials, or neither.

See how this compares in every state: Sales tax on labor for plumbers and HVAC contractors by state

Materials	You are the consumer of materials (pipe, fittings, wire, cement, anything that loses its identity once installed). You pay sales tax when you buy them and do not charge the customer tax on them.
Fixtures (things attached to the building)	You are the retailer of fixtures (items that stay recognizable after installation, such as plumbing fixtures, sinks, water heaters, and water softeners built into the water system). You charge the customer sales tax on the fixture. In a lump-sum contract the tax is worked out on what the fixture cost you.
Installation labor	No sales tax
Homes versus businesses	Same rules for a home and a business
New buildings	Same rules as repair and remodel
Repairs	In a lump-sum repair you pay tax on the parts and charge the customer nothing. If you bill the parts separately from the labor, or you replace the whole fixture, you charge the customer tax on the parts or fixture.
When you quote one total price	You pay tax on materials at cost and report tax on fixtures at your cost. Listing materials, labor, and tax separately on the invoice does not turn a lump-sum contract into a time-and-material one.
When you bill time and materials	You are still the consumer of materials unless you bill sales tax on a marked-up materials charge, or the contract passes title to the materials before installation and states their price separately. Then you are the retailer and charge tax on the materials.
Seller's permit	Usually not needed if you only install materials under lump-sum contracts. Needed if you sell and install fixtures.
Tax rate	7.25 percent statewide, plus district taxes of 0.10 to 2.00 percent in many cities and counties

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·4 official pages

9 Getting paid: lien and notice deadlines for a California plumber What is this?

If you are not paid in California, a lien on the property is your backstop, but only if your notice goes out on time: within 20 days of your first day of work on the job (first day on January 10 means notice by January 30). A late notice still counts, but only for work done in the 20 days before you served it and after.

Who has to send a notice	Everyone who wants to keep the right to file a lien, except workers paid by the hour. If you were hired by the property owner, you only need to send the notice to the construction lender, if there is one. If you were hired by a contractor, send it to the owner, the direct contractor, and any lender.
Send your notice by	Within 20 days of your first day of work on the job (first day on January 10 means notice by January 30). A late notice still counts, but only for work done in the 20 days before you served it and after.
File your lien by	If the owner hired you, record the lien within 90 days of the project being finished, or within 60 days after the owner records a notice of completion or cessation, whichever comes first (project finished March 1 with no notice recorded means lien by May 30). If a contractor hired you, the 60 days becomes 30 days.

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·4 official pages

10 How much does it cost to become a plumber in California? What is this?

The government fees on this page add up to about $800 in California. Add insurance, tools, and a vehicle to get the real number.

Government fees, added up	$800

Does not include the $25,000 bond premium, insurance premiums, live scan rolling fees, tools, a vehicle, or city permits and business licenses

Our estimate

11Where these numbers come from

The labels under each table are explained on how to read a page.