How do I check a contractor's license in California?

California has the most rigorous contractor licensing system in the US. The Contractors State License Board (CSLB, cslb.ca.gov) regulates all contractors performing work valued at $500 or more in materials and labor combined.

License classes:

- A: Engineering Contractor — fixed works, public infrastructure. - B: General Building Contractor — buildings using at least two unrelated trades. - B-2: Residential Remodeling Contractor (added 2021) — residential alterations only. - C-specialties: 41 specific trades, including C-10 Electrical, C-20 HVAC, C-36 Plumbing, C-39 Roofing, C-33 Painting, C-53 Swimming Pool, C-54 Ceramic and Mosaic Tile.

A "B" license can perform work involving two or more unrelated trades. A C-specialty license can only perform work in that specialty, plus any work "incidental and supplemental" to the specialty.

What to check at cslb.ca.gov:

1. License number, business name, qualifier match. 2. Status: Active (good), Inactive (paused), Suspended (open issue), Revoked (terminated), Expired (lapsed). 3. License class: must match the work being quoted. 4. Bond status: $25,000 contractor's bond required for all licenses. Current = good. Insufficient or canceled = walk away. 5. LLC employee bond: if the contractor is an LLC, additional $100,000 LLC employee/worker bond required. 6. Workers' compensation: must show current account if the contractor has employees. Exempt-from-WC contractors (true sole proprietors with no employees) can carry an exemption certificate. 7. Disciplinary history: CSLB publishes citations, license bars, and administrative actions. Read the actual citation documents. 8. Personnel listing: shows the qualifying party and any RMOs (Responsible Managing Officers).

California-specific consumer protections:

- Deposit cap: 10% of contract value or $1,000, whichever is less (B&P Code §7159). - 3-day right to cancel home improvement contracts signed at home. - Mechanics' lien Preliminary Notice required within 20 days of starting work. - CSLB complaint process can result in restitution orders. - Contractors State License Board Recovery Program: not a recovery fund per se, but CSLB can order restitution as part of disciplinary actions.

Common California contractor issues:

- C-specialty license used for B-license work. A C-36 plumbing license cannot do a kitchen remodel — only plumbing within that remodel. - Inactive license used for ongoing work. Contractors sometimes go "Inactive" to save fees; work performed during Inactive period is unlicensed. - LLC without LLC employee bond. CSLB requires the additional $100,000 bond for LLC-organized contractors. Missing this bond means the LLC's workers are not bonded. - Workers' comp exemption claim by a contractor who actually has employees. If the contractor has any W-2 employees, the exemption is invalid.

Earthquake retrofit work has additional requirements: the Earthquake Brace + Bolt program requires CEA-approved contractors. Solar requires C-46 specialty class.

Groundcheck (earthmove.io/trust) verifies California CSLB licenses including all of the above fields, plus cross-references the entity at the California Secretary of State (bizfileonline.sos.ca.gov), checks California Superior Court records by county, checks federal court records via PACER, and checks OSHA enforcement records. California is the most data-rich state for contractor verification.