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Homeowner guide

How to check a contractor's license in California

A five-minute check before you sign can save you thousands. Here is exactly what to look at, what it means, and the warning signs to walk away from. Last reviewed October 22, 2026.

Browse licensed Los Angeles County plumbers or HVAC contractors in our license directory, then verify any contractor on the state's own license check.

Do they even need a license?

Under California law, construction work valued at $1,000 or more in labor and materials combined must be done by a contractor licensed by the Contractors State License Board (CSLB). If the job needs a permit or the contractor hires workers, a license is required no matter how small the price. Splitting a job into smaller pieces to stay under $1,000 is illegal. Plumbing and HVAC replacements almost always need a license.

Step 1: Get the license number

Ask for the contractor's CSLB license number and the exact business name on the license. Write both down. A real contractor will give them without hesitation.

Step 2: Look it up on the CSLB site

Go to the CSLB License Check and search by license number. Confirm four things:

  • Status. It should be active and in good standing, not suspended, expired or cancelled.
  • Classification. It must fit the job. For example C-36 is Plumbing and C-20 is Warm-Air Heating, Ventilating and Air-Conditioning (HVAC). C-39 is Roofing.
  • Business name and location. They should match the contract and the truck.
  • Bond and workers' compensation. See below.

Step 3: Understand the bond

Every licensed contractor must have a $25,000 contractor license bond on file with CSLB, from a surety company or as a cashier's check. The bond is not per job: it is the pool available for all of a contractor's jobs over its life. If a bond is cancelled and not replaced within 30 days of CSLB receiving the cancellation notice, the license is suspended. The license page has a "Contractor's Bond History" link that shows which surety was on the bond when you signed.

Step 4: Check workers' compensation

Employers with even one part-time employee must carry workers' compensation insurance. The license page shows the contractor's coverage. If it says the contractor is exempt, that means they report having no employees. If a crew shows up to your house, ask about it before work starts.

Step 5: Know the payment rules

  • A down payment may not exceed 10% of the contract price or $1,000, whichever is less. CSLB notes an exception for contractors who have filed a blanket performance and payment bond.
  • Apart from the down payment, a contractor cannot demand or accept payment for work or materials until the work is done or the materials are delivered. Payment schedules should track real progress.

Step 6: Know your right to cancel

If you signed the contract at your home and not at the contractor's place of business, you generally have three days to cancel, and the contract should say so. CSLB lists exceptions, including repairs after a declared natural disaster, so check its current guidance for your situation.

Get at least three bids

CSLB recommends getting at least three bids, checking references before you sign, and comparing the same scope of work. Use our estimate checker to see what your estimate is missing.

Seven red flags

  1. No license number, or one that doesn't match the name you were given.
  2. A license classification that doesn't fit the work.
  3. A suspended, expired or cancelled license.
  4. A deposit larger than the 10%/$1,000 limit, or a demand to pay in full up front.
  5. Pressure to sign today, or a price that is only good "right now."
  6. Cash-only deals, or a suggestion to skip the permit.
  7. A crew that shows up when the license says the contractor has no employees.
If something goes wrong, you can file a complaint with CSLB. A licensed contractor's bond may help in some cases. Keep your contract, payments and photos.

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