How do I check if a California contractor is licensed?

Go to cslb.ca.gov and use the License Check tool. Enter the contractor's license number, business name, or personal name. The CSLB will show whether the license is active, what classification it covers (e.g., C-20 HVAC, C-36 Plumbing), bond status, and workers' compensation status.

What is a CSLB license number?

Every licensed California contractor is issued a unique number by the Contractors State License Board (CSLB). The number is required on advertisements, contracts, and vehicles. If a contractor can't produce theirs on request, that's a red flag.

What does it mean if a contractor's license is 'active'?

An active license means the contractor has met CSLB's requirements (passed the trade exam, posted a bond, carries workers' compensation if they have employees) and is currently authorized to work in California. Statuses like 'inactive,' 'suspended,' or 'expired' mean the contractor is not legally allowed to perform work over $500.

Should I hire a contractor without a CSLB license in California?

Not for any project over $500. California law requires a CSLB license for that threshold. Unlicensed contractors carry no bond, no liability insurance, and you forfeit access to CSLB's mediation and enforcement tools if anything goes wrong. The financial risk almost always exceeds the savings.

What's the difference between a Class A, B, and C contractor license?

Class A is general engineering (large public works, infrastructure). Class B is general building (most residential and commercial construction over multiple trades). Class C is specialty (one trade per license — C-20 HVAC, C-36 Plumbing, C-10 Electrical, C-39 Roofing, etc.). Match the license class to the work you're hiring for.

How do I report an unlicensed contractor in California?

File a Lead Referral with the CSLB at cslb.ca.gov/OnlineServices/LeadReferrals. Unlicensed contracting is a misdemeanor on first offense and a felony for repeat offenders. The CSLB takes these reports seriously and can issue stop-work orders and pursue prosecution.

Do I have to verify a contractor's license myself if I use Home Trade Pros?

No. Every contractor on Home Trade Pros has had their CSLB license verified before they can purchase a lead, and we automatically re-verify status against the CSLB master file daily. If a license expires, is suspended, or is revoked, the contractor is removed from the platform until it's restored.

How to Verify a California Contractor's License

A free, two-minute CSLB lookup that protects you from unlicensed work, missing bonds, and uninsured contractors.

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The Short Version

Every California contractor doing work over $500 is required by law to hold an active license from the Contractors State License Board (CSLB). Verifying a contractor's license takes about two minutes and is free.

You have two paths:

Verify it yourself using the CSLB License Check tool at cslb.ca.gov. The step-by-step walkthrough is below.
Skip the lookup by using a platform that has already verified every contractor on it. Home Trade Pros verifies every contractor against the CSLB master file before they're allowed to contact homeowners.

How to Verify a Contractor on cslb.ca.gov

The CSLB License Check tool is free and public. Here's exactly what to do.

Go to the CSLB License Check tool

Visit cslb.ca.gov and click 'License Check' from the homepage. The tool is free and does not require an account.

Enter the license number, business name, or personal name

California license numbers are typically 6–7 digits. If you don't have the number, you can search by business name or the contractor's personal name. Watch out for typos and similar-sounding business names — verify it's the exact contractor you're considering.

Confirm the license is 'active'

An active license means the contractor is currently authorized to work in California. Avoid contractors whose status shows inactive, suspended, expired, or revoked. Each of those means they cannot legally take on your project.

Match the license classification to your project

California issues licenses by classification. A C-36 Plumbing license cannot legally do HVAC work. A C-20 HVAC license cannot legally rewire your panel. Match the classification to the actual job you're hiring for.

Verify bond and workers' compensation

The CSLB record shows whether a contractor's bond is current (a $25,000 contractor's bond is required in California) and whether they carry workers' compensation insurance. If a contractor doesn't carry workers' comp and one of their employees is hurt on your property, you can be held liable.

What to Look for on the CSLB Record

Five fields that determine whether a contractor is safe to hire.

License status

What you want: Active

Red flag: Inactive, suspended, expired, revoked

Classification

What you want: Matches the trade you're hiring for (e.g., C-36 for plumbing)

Red flag: Different trade than the job

Bond

What you want: $25,000 contractor bond on file, current

Red flag: No bond or expired bond

Workers' comp

What you want: Active policy or valid exemption

Red flag: No coverage if they have employees

Personnel record

What you want: Listed RMO/RMQ with verifiable history

Red flag: Recent personnel changes with no history

Complaint history

What you want: Few or no actionable complaints

Red flag: Pattern of unresolved disputes or judgments

Signs You're Dealing with an Unlicensed Contractor

⚠They refuse to put their CSLB license number on a written estimate or contract.
⚠Their license number doesn't appear on their truck, business cards, or website (California requires it).
⚠They demand more than 10% or $1,000 down payment before starting work — also illegal in California.
⚠They insist on cash-only payment and won't provide a written contract.
⚠They tell you the project is 'too small' to require a license, even though it's clearly over $500.
⚠Their CSLB record shows expired or suspended status when you look it up.
⚠Reviews online point to vanishing during the job, missing payments to subs, or property damage.

Frequently Asked Questions

Or Skip the Lookup Entirely

Every contractor on Home Trade Pros is CSLB-verified before they can contact you. Submit a project and only get matched with active, licensed pros.

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