How to check a California contractor license (CSLB): a GC's checklist
Short answer
- Look up the sub's license number on the CSLB's free Instant License Check.
- Confirm the business name, an Active status, the right classification for the work, the expiration date, a bond, and workers' comp (a policy or a filed exemption).
- Write down the date you checked. Status can change, so check again before the sub starts.
- CSLB records don't show general liability for most licensees, so ask for a certificate of insurance too.
Why it matters
Hiring an unlicensed or wrongly classified sub can cost you: California generally bars unlicensed contractors from suing to get paid, a licensee who contracts with an unlicensed contractor can face CSLB discipline, and an uninsured sub's crew can end up on your workers' comp audit. A two-minute lookup avoids most of it.
Step by step
- Get the license number. California contractors have to show it on bids, contracts and ads. If a sub won't give it to you, that's your answer.
- Look it up on CSLB. Use the board's free Instant License Check. Search by license number, not by name, so you land on the right record.
- Match the business name. The name on the license should be the company on your subcontract and on their certificate of insurance.
- Status should read "Active". Anything else (expired, suspended, inactive) means stop and ask.
- Check the classification against the scope. Electrical work needs a C-10, plumbing a C-36, roofing a C-39, and so on. A B (general building) license has its own limits on taking specialty work.
- Check the expiration date against your schedule.
- Look for a contractor's bond on the record.
- Read the workers' comp section. You'll see either a policy (carrier, policy number, dates) or an exemption, meaning the contractor stated in writing that they have no employees. See workers' comp and subs.
- Save the date you checked (a screenshot or PDF works) and check again before the sub starts and before your audit.
What the CSLB lookup doesn't tell you
- General liability. CSLB's records don't include GL for most licensees. Get a certificate of insurance and the endorsements your contract requires.
- Whether the coverage covers you. Additional insured status and waivers come from endorsements, not the license record.
- Quality of work. References, past jobs and your own judgment still matter.
CSLB also publishes free bulk lists through its data portal; those are current only as of their posted date, so use Instant License Check for live status.
General information for California contractors, current as of November 3, 2026. It isn't legal advice; rules change, so check the official source linked above.
More guides
- Workers' comp and subcontractors in California: what GCs should check
- Certificate of insurance checklist for California general contractors
- Additional insured and waiver of subrogation for subcontractors: a California GC's guide
- Risks of hiring an unlicensed subcontractor in California (for GCs)
- Workers' comp premium audits and subcontractors in California: how to prepare
- California contractor's license bond ($25,000): what it covers for a GC
- Matching a sub's California license classification to the work