How to Verify a Contractor License in California: CSLB Lookup Step by Step

Why Altadena Homeowners Must Verify Before They Hire

In December 2025, the LA County District Attorney filed felony charges against five unlicensed contractors caught working in the Eaton Fire zone — a reminder that rebuilding Altadena has attracted predators alongside legitimate builders. For homeowners planning a custom home or rebuild, the difference between the two often comes down to a thirty-second check you can run yourself.

The legal stakes are unusually high here. Contracting without a license on structures damaged in a Governor-proclaimed disaster is a felony punishable by up to 3 years in prison and/or a $10,000 fine, and one of the five defendants faces up to 6 years due to prior convictions, according to the DA's announcement. That's a sharp escalation from the misdemeanor treatment unlicensed contracting usually receives — and a direct response to the more than 12,000 homes and structures destroyed in the LA County wildfires.

Enforcement isn't limited to a handful of prosecutions. A November 2025 coordinated enforcement sweep across 17 counties produced 119 legal actions, 454 site visits, 27 stop-work orders, and 26 referrals to district attorneys. CSLB warns that unlicensed "storm chasers" deliberately follow disasters, preying on homeowners desperate to rebuild.

Here's the trap most homeowners fall into: assuming a license number printed on a truck or flyer means the license is valid. It doesn't. California requires the license number on all contractor advertising, but CSLB is explicit that seeing a number doesn't confirm the license is active, in good standing, or even held by the person who printed it. A number can be expired, suspended, or borrowed from someone else entirely.

What verification actually protects you from:

• Contractors working outside their license classification for your project
• Missing workers' comp coverage — if a worker is injured on your property and the contractor is uninsured, you could be financially liable
• Undisclosed complaints on the contractor's record
• Down-payment schemes that exceed the legal cap of 10% or $1,000, whichever is less

The good news is that verification is trivially easy. CSLB Registrar David Fogt notes that it "only takes a few seconds" to check a license on CSLB's website, and the board operates a dedicated Disaster Help Center for wildfire survivors. At Altadena Custom Home Builder, we encourage every homeowner to verify any builder they're considering — including JMB Builders LLC (CSLB #1103479), the licensed Altadena general contractor featured on this site. Run the check yourself, then schedule a free build consultation to talk through your lot, your design, and your rebuild path.

The CSLB Lookup: Your Free, Official Verification Tool

Before you hand a deposit to anyone — especially for an Eaton Fire rebuild — you can confirm their license in less time than it takes to read this paragraph. CSLB Registrar David Fogt puts it plainly: it only takes a few seconds to verify a contractor's license on the state's website, and those few seconds can save you from a felony-level scam.

The official CSLB license lookup is completely free and works three ways. If you have a license number — every contractor ad, from truck signage to flyers, is legally required to display one — search by that number first. No number handy? You can also search by business name or by the contractor's personal name.

One caution from CSLB itself: seeing a license number in an ad doesn't mean the license is valid. Numbers can be expired, suspended, or borrowed from someone else. The lookup is the only way to confirm the record behind the number.

The license record tells you what matters most:

• Current license status and classification, including any complaint disclosure
• Whether the contractor carries a $25,000 contractor license bond and workers' compensation insurance (or a valid Certification of Self-Insurance)
• The contractor's address of record — worth checking if they claim to be local
• Insurance details, including workers' comp and commercial general liability, on the license history page

The same tool also verifies Home Improvement Salesperson (HIS) registrations. If a salesperson knocks on your door soliciting fire-rebuild work, CSLB advises asking for their HIS registration card alongside photo I.D. — then confirm the registration in the lookup the same way you'd check a license.

Prefer the phone? Call CSLB toll-free at (800) 321-CSLB (2752) to verify a license or registration, or to ask questions before you sign a contract.

For Altadena homeowners, there's a disaster-specific resource too. CSLB operates a Disaster Help Center specifically for verifying licenses and filing complaints in declared-emergency zones — a direct response to unlicensed "storm chasers" who prey on wildfire survivors. The urgency is real: the LA County DA recently filed felony charges against five unlicensed contractors working in the Eaton Fire zone, where unlicensed contracting on disaster-damaged structures carries up to 3 years imprisonment and a $10,000 fine.

We encourage every reader to run this check on any builder they're considering — including the builders we feature at Altadena Custom Home Builder, such as JMB Builders LLC (CSLB #1103479). A builder who welcomes verification is one worth talking to.

What to Check on the License Record: A 5-Point Checklist

A license number on a truck door or website means little on its own — as CSLB puts it, "seeing a license number doesn't necessarily mean the license is valid." The real story lives in the license record itself. Here's what to look for once the lookup returns a result, and what "good" actually looks like.

1. Active status and the right classification. The record should show an active license, and for a ground-up custom home or Eaton Fire rebuild, you want a B General Building Contractor classification. CSLB licenses contractors across 45 classifications, and a B license authorizes the holder to perform or subcontract all work on jobs involving more than two trades — exactly what a custom home build requires, according to CSLB's classification guidance.

2. Complaint disclosure. The lookup results include complaint disclosure, per CSLB's official tool description. A complaint isn't automatically disqualifying, but a pattern of unresolved complaints — especially ones involving work quality or abandonment — deserves scrutiny before you hand over a deposit.

3. The $25,000 contractor bond. Every licensed contractor must carry a $25,000 contractor license bond, and the record shows whether it's in place. One critical caveat from CSLB: bonds do not assure the financial or professional integrity or competency of a contractor. The bond is a floor of consumer protection, not proof of quality — treat it as a baseline requirement, not an endorsement.

4. Workers' compensation or self-insurance. The license record shows whether the contractor carries workers' compensation insurance or a valid Certification of Self-Insurance. This matters more than most homeowners realize: CSLB warns that if a worker is injured on your property and the contractor has no insurance, you could be financially liable for injuries and rehabilitation. On a hillside lot in Altadena, where framing crews work on slopes and scaffolding daily, that risk is not theoretical.

5. The address of record. Check that the address on the license matches where the contractor says they operate. A record showing a P.O. box three counties away from the "local" builder who knocked on your door is a red flag worth pausing on — particularly in a disaster zone where out-of-area operators have drawn enforcement attention.

A quick summary of what a clean record looks like:

• Active status with a B General Building classification for custom home work
• No pattern of unresolved complaints in the disclosure
• A current $25,000 bond on file
• Workers' comp coverage or a valid Certification of Self-Insurance
• An address of record consistent with where the builder claims to operate

You can run this same five-point check on any Altadena builder — including JMB Builders LLC (CSLB #1103479) — in seconds, as CSLB Registrar David Fogt notes it "only takes a few seconds to verify a contractor's license information on CSLB's website," per recent enforcement coverage. Altadena Custom Home Builder encourages every homeowner to do exactly that before signing anything; if you'd like help interpreting a license record or planning a rebuild, our free build consultation is a good place to start.

Beyond the Lookup: Guardrails Before You Sign

Passing the CSLB lookup is only half the job. What happens face-to-face and at the contract table matters just as much — and it's where disaster-zone survivors, in particular, get burned.

Start in person. Ask to see the contractor's pocket license along with photo I.D., and make sure the name matches what you saw in the online lookup. If a salesperson is doing the selling, they must be registered with CSLB as a Home Improvement Salesperson — ask for their registration card and I.D. too, per CSLB's hiring guidance.

Before you compare prices, get bids the right way. CSLB recommends collecting at least three written bids on identical plans and specifications — otherwise you're comparing apples to oranges. For an Altadena custom build or Eaton Fire rebuild, that means giving each bidder the same scope for the same hillside lot, the same permits path, and the same finishes.

Then protect your cash. California law caps the down payment at 10% of the contract price or $1,000, whichever is less. The only exception is when a contractor holds a Blanket Performance and Payment Bond on file with CSLB — and only about two dozen licensees statewide carry one, so don't accept "I have a bond" as an excuse to pay more upfront.

• Verify the pocket license and photo I.D. against the CSLB record.
• Confirm any salesperson's Home Improvement Salesperson registration.
• Get at least three bids on identical plans and specs.
• Never pay more than 10% or $1,000 down without a Blanket Performance and Payment Bond.
• Request current certificates of insurance, including from subcontractors.

Insurance documentation deserves its own ask. Beyond the workers' compensation status visible on the license record, request current certificates of insurance for general liability — and ask that subcontractors provide theirs before mobilization, a practice recommended in commercial contractor guidance. If an uninsured worker is injured on your property, CSLB warns you could be financially liable for injuries and rehabilitation.

Remember, too, that a bond is a floor, not a endorsement. As CSLB puts it, bonds "do not assure the financial or professional integrity or competency of a contractor" — the $25,000 bond protects you from certain losses, but it says nothing about build quality.

One last sanity check: any legitimate builder will welcome this scrutiny. JMB Builders LLC (CSLB #1103479), the licensed Altadena general contractor featured on this site, can be verified in seconds on the CSLB lookup — and so can any builder you're considering for a ground-up custom home, tear-down rebuild, or Eaton Fire rebuild. If a contractor bristles at showing a pocket license or balks at the down-payment cap, that's your answer. When you're ready to talk through your project with someone who expects the verification, request a free build consultation.

Verify Any Altadena Builder Yourself — Then Build with Confidence

You don't need to take any builder's word for their credentials — including ours. The CSLB's free online license lookup lets you verify any Altadena contractor in what Registrar David Fogt calls "a few seconds," checking status, complaints, bonding, and insurance before you commit to a six-figure rebuild.

Take the featured builder on this site as a working example. JMB Builders LLC, an Altadena-based general contractor, holds CSLB license #1103479 — a number disclosed here as a paid placement. Plug it into the lookup and you'll see the license status, complaint disclosure, the required $25,000 contractor license bond, workers' compensation coverage, and the address of record on file. If a builder won't share their license number, that itself is an answer.

This matters more in Altadena right now than almost anywhere in California. In December 2025, the LA County District Attorney charged five unlicensed contractors with felonies for working in the Eaton Fire zone, where contracting without a license on disaster-damaged structures carries up to 3 years imprisonment and a $10,000 fine, according to the District Attorney's announcement. With more than 12,000 homes and structures destroyed in the LA County wildfires, the CSLB has stood up a Disaster Help Center specifically for license verification and complaints.

A license number on a truck or website doesn't guarantee validity — CSLB says so explicitly. Before signing with any builder for a ground-up custom home, tear-down rebuild, or Eaton Fire rebuild, run through this quick check:

• Verify the license status and complaint history on the CSLB lookup, searching by license number, business name, or contractor name.
• Ask to see the pocket license with photo I.D. in person, and confirm any salesperson is a registered Home Improvement Salesperson.
• Confirm workers' compensation and liability insurance — if an uninsured worker is injured on your property, you could be financially liable.
• Never pay more than 10% or $1,000 down, whichever is less, and get at least three written bids on identical plans.

One caveat from CSLB itself: a bond "does not assure the financial or professional integrity or competency of a contractor." Verification is your floor of protection, not a guarantee of craftsmanship — which is why we pair license checks with site visits, references, and detailed written scopes on every project we cover at Altadena Custom Home Builder.

If you're planning a hillside custom home, an SB 9 lot split, or an Eaton Fire rebuild in Altadena, start with a free build consultation. We'll walk your lot, your goals, and your verification checklist — and you can confirm every license number we mention, including #1103479, on the CSLB site yourself before we ever talk numbers.