How to check a California contractor license

In California, anyone who does construction work worth $1,000 or more (labor and materials), or any work that needs a building permit or uses hired workers, must hold a license from the Contractors State License Board (CSLB). [CSLB, AB 2622]

1. Get the license number. Contractors must show it on ads, bids, contracts and business cards. [CSLB]
2. Look it up. Search here or on CSLB's official Check a License page. CSLB's page is the final word and shows complaint disclosures.
3. Status should be "CLEAR" / active. Any suspension (bond, workers' comp, judgment) means the contractor can't legally work until it's fixed.
4. Match the classification to your job. A roofing job needs a C-39 or a B general contractor managing it, etc. See what each classification means.
5. Check the bond and workers' comp. See what they mean.
6. Match the name. The business and the person you're dealing with should match the license record. Ask for the pocket license and a photo ID.

Then get at least three written bids based on the same plans. [CSLB]