Check a plumber's license before you hire. Here's how to read it.
California publishes every contractor's license record on a free state website. Four fields on that record — status, classification, bond, and workers' comp — tell you most of what you need to know before anyone touches your plumbing. This guide explains each field in plain language and walks through the lookup step by step. It takes about three minutes. This is the same public record we check for every company on our Oceanside plumber list — our methodology explains exactly how.
· Jul 6 2026
What a CSLB record tells you, field by field.
CSLB is the Contractors State License Board — the California agency that licenses and regulates contractors. Every license record it publishes shows these four fields.
- Field 1
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License status
The status line at the top of the record. You want it to read "current and active." Anything else — expired, suspended, revoked, inactive — means CSLB does not consider the company able to contract under that license right now.
In one line: if the status isn't "current and active," stop and ask why before going any further.
- Field 2
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Classification (C-36)
Classifications are the trades a license covers. C-36 is California's plumbing classification. Some plumbing companies also hold others — C-20 (heating/air) or B (general building) — but for plumbing work, C-36 is the one to look for on the record.
In one line: a company holding only a B (general building) license is not licensed as a plumbing specialty contractor.
- Field 3
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Contractor bond
CSLB requires every active licensee to keep a contractor bond on file — currently $25,000, an amount set by SB 607 effective January 1, 2023 (confirm the current figure on CSLB's site). A bond is not insurance: it is a limited fund a harmed homeowner can file a claim against.
In one line: the record should show a bond on file with a surety company; no bond generally means no active license.
- Field 4
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Workers' compensation
The record shows either an insurance policy — carrier, policy number, and dates — or an exemption stating the contractor has certified they have no employees. If a company has employees on your job, workers' comp is what covers on-the-job injuries so an injury claim doesn't land on you.
In one line: "insured" should show current policy dates; "exempt" means a certified no-employee operation — see below for when that matters.
Check-A-License, step by step.
The official tool is CSLB's Check-A-License at cslb.ca.gov. It's free, public, and requires no account.
Open CSLB's Check-A-License
Go to cslb.ca.gov's Check-A-License page. Make sure you're on cslb.ca.gov — the state's own site — not a third-party lookup wrapped around it.
Search by license number (fastest) or business name
Ask the plumber for their license number — California law requires contractors to include it in their advertising and contracts (Business & Professions Code §7030.5), and most publish it on their website footer. No number handy? Search by business name instead.
Shortcut: typing the license number directly after cslb.ca.gov/ jumps straight to the record — for example, cslb.ca.gov/982295 opens the record for license #982295 (Personal Plumbing Heating & Air Conditioning, the #1-ranked company on our Oceanside list).
Confirm the record matches the company you're talking to
The registered business name or a listed DBA ("doing business as") should correspond to the company you're dealing with, and the city, phone, or address should corroborate it. DBAs are normal — on our July 6, 2026 check, 1st Choice Plumbing, Flood & Restoration's license #972962 is registered to "1ST CHOICE INVESTMENT BUILDERS INC" doing business as "1ST CHOICE PLUMBING HEATING AND AIR," and the CSLB address matches the Oceanside address the company publishes. A name mismatch nobody can explain is different — that's a reason to pause.
Read the four fields
Status ("current and active"), classification (C-36 for plumbing), bond (on file), and workers' comp (insured with current dates, or exempt). The four-field guide above explains what each means.
Check the dates
The license expiration date should be in the future, and any workers' comp policy dates should be current. A record can look fine at a glance and still show a policy that lapsed last month — the dates are where that shows up.
California caps the down payment. Know the number.
The down-payment cap for home-improvement contracts
The down payment may not exceed $1,000 or 10 percent of the contract price, whichever is less.
That is the rule for home-improvement contracts under California Business and Professions Code section 7159 — read the statute text at leginfo.legislature.ca.gov, and confirm current consumer guidance on CSLB's consumer pages. In practice: on a $12,000 repipe, the most a contractor can ask for up front is $1,000; on a $6,000 water-heater job, it's $600.
Two honest caveats: narrow statutory exceptions exist (for example, for contractors who have posted certain additional bonds with CSLB), and emergency service-and-repair work follows related but separate rules. If a quote asks for a large deposit, checking the current rules on CSLB's site takes less time than getting the money back.
When "workers' comp: exempt" matters — and when it doesn't.
An exemption on the workers' comp line means the contractor has certified to CSLB that they have no employees. For a genuine one-person operation, that is lawful and normal — it is not a defect, and some companies on our ranked list run exactly this way. Two examples from our own July 6, 2026 check of Oceanside plumbers:
- Drains4Less Plumbing — license #1010148, workers' comp exempt (certified no employees, effective January 13, 2026).
- 1st Choice Plumbing, Flood & Restoration — license #972962, workers' comp exempt (certified no employees, effective January 6, 2026).
When it matters: the exemption is a certification that no employees exist. If a company whose record reads "exempt" sends a multi-person crew to your job, the certification and the reality don't match — ask who employs the extra workers before the job starts. An injury to an uninsured worker on your property is a problem you want answered on day zero, not after something happens.
When it doesn't: a solo operator working alone. The record and the truck match, and the exemption is doing exactly what it was designed to do.
Three questions homeowners actually ask.
Yes. CSLB's Check-A-License is a free public tool run by the State of California. You never need to pay anyone — including this site — to see a contractor's license record. If a service offers to "verify" a license for a fee, the same information is available directly from CSLB at no cost.
CSLB marks an expired license as not able to contract — the company cannot legally take on new work under that license until it is renewed. A real example from our own directory: on our July 6, 2026 check, license #943193 (Vets for You Plumbing) read "This license is expired and not able to contract at this time," expired March 31, 2024. We delisted the company from our ranked list the same day and documented the record on its profile.
For a home-improvement contract, California caps the down payment at the lesser of $1,000 or 10 percent of the contract price, under Business and Professions Code section 7159. Narrow statutory exceptions exist, and service-and-repair work follows related rules — confirm the current rules on CSLB's consumer pages before you sign, and never pay in full before the work is done.
This guide is general consumer information, not legal advice, and Coastal SD Pros is not affiliated with the Contractors State License Board. Coastal SD Pros is an independent directory and lead-referral service, not a licensed plumbing contractor. License examples reflect CSLB records as of July 6, 2026 and can change — always verify the live record on cslb.ca.gov before hiring. Sponsored placements are paid advertising and are labeled as such; none are currently active.