How to hire a plumber in California
Three steps: check the license, get a written contract, and watch the down payment. The legal points below come from the California codes we read on November 5, 2026. This is general information, not legal advice.
1. Check the license
- Ask the plumber for their CSLB license number.
- Look it up on the CSLB license check. Confirm the license is active and that the C-36 Plumbing classification is listed.
- Compare the business name with the one on your quote and contract.
This directory lists C-36 licensees by county and city. A listing is not an endorsement, and the data can be out of date, so always check the CSLB.
2. Know when a license is required
California's rule is in Business and Professions Code section 7048. A license is not required when the total price for labor, materials and all other items on one project is under $1,000, the work is minor, and it does not require a building permit. The exception does not apply to a person who advertises as a contractor or who employs others to do the work, and it does not apply when a larger job is split into small contracts to avoid the law.
3. Get it in writing
Business and Professions Code section 7159 sets the rules for a written home improvement contract. As we read it, the contract must include:
- A description of the project and the work to be done.
- If a down payment is charged, a heading "Downpayment" with the amount and this statement in bold type: "THE DOWNPAYMENT MAY NOT EXCEED $1,000 OR 10 PERCENT OF THE CONTRACT PRICE, WHICHEVER IS LESS."
- The applicable Notice of Cancellation, included in or attached to the contract. If it is missing, the section says the buyer may file a complaint with the Contractors State License Board.
Section 7159 says it does not apply to certain smaller service and repair contracts, which fall under sections 7159.10 to 7159.14. We did not read those sections, so this page does not summarize them.
Questions to ask before you say yes
- What is your CSLB license number?
- Is the price for the whole job, and what is not included?
- Does the price include the permit, if one is needed? Your city or county building department decides that.
- How much is the down payment, and when are the remaining payments due?
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