California contractor licenses: how CSLB licensing works

Classifications

The Contractors State License Board (CSLB) licenses contractors by classification: A for general engineering, B for general building, B-2 for residential remodeling, and 42 C specialty classifications for individual trades. A license covers only the work its classifications allow, so check that the classification matches the job. Some examples:

• A - General Engineering Contractor
• B - General Building Contractor
• B-2 - Residential Remodeling Contractor
• C-10 - Electrical Contractor
• C-36 - Plumbing Contractor
• C-39 - Roofing Contractor

The full list is on CSLB's classifications page.

Getting licensed

Each license has a qualifying individual for its classifications. CSLB requires applicants to pass the law and trade examinations unless they have served as a qualifying individual for the same classification, or passed those examinations, within the past five years.

Checked on CSLB's site 2026-10-06. Requirements, fees and the dollar threshold for work that needs a license change over time — confirm on CSLB's application page.

Verifying a license

Before you hire or subcontract, look the license up on CSLB's License Check and confirm the status is current, the classifications fit the work, and workers' compensation and the contractor's bond are on file. For public works, the contractor must also be registered with the Department of Industrial Relations — see the public works guide.

Atriam's contractor lookup shows the same CSLB license facts next to each contractor's public works history from DIR records.