How to check an HVAC contractor's license in California

The lookup, step by step

1. Open the CSLB Check a License page.
2. Enter the license number from the quote, the truck or the contractor's pocket license. Searching by business name works too, but the number avoids look-alike names.
3. Confirm the status reads active and the classifications include C-20.
4. Open the bond and workers' compensation sections and check both are current.
5. Check the licensed business name matches the name on your quote and contract.

What the C-20 classification covers

California licenses HVAC contractors through the Contractors State License Board. The C-20 classification (Warm-Air Heating, Ventilating and Air-Conditioning) covers installing, servicing and repairing heating systems, air-conditioning systems complete with the unit, and the ducts, registers, controls and filters connected to them.

Since 1 January 2025, work totaling $1,000 or more in labor and materials needs a CSLB license. Below that, an unlicensed person may do the job only if no building permit is needed and they hire no workers. An AC installation needs a permit, so it needs a license at any price.

Bond and workers' compensation

Every licensed California contractor must carry a $25,000 contractor license bond, raised from $15,000 on 1 January 2023 by SB 607.

The bond is not insurance for your job; it is a limited fund for claims against the license. A contractor with employees must carry workers' compensation; the CSLB record shows the policy or an exemption.

Red flags on the record or the quote

• No license number on the quote, or a number that returns a different business.
• A license that is expired, suspended, or lacks C-20.
• A workers' comp exemption from a contractor who sends a crew.
• A suggestion to skip the permit to save money.
• A deposit above 10 percent of the contract or $1,000, whichever is less.
• A salesperson who cannot give the license number of the company they sell for.

Contract terms to check

CSLB cautions that a down payment should not exceed 10 percent of the contract price, and later payments should not run ahead of the work done or materials delivered.

CSLB's own wording is stricter than most people expect: the down payment should never exceed 10 percent of the contract price or $1,000, whichever is less. On a $12,000 heat pump job that is $1,000, not $1,200. The one exception is a contractor with a blanket performance and payment bond on file with CSLB, which you can see on the license record.

Any home improvement job over $500 in labor and materials needs a written contract. CSLB says it must name the contractor, their address and license number, and should spell out:

• the work, with equipment make, model and size (in tons or Btu/h);
• the price and when each payment is due;
• who pulls the building permit (on an AC job, the contractor should, in their own name);
• start and finish dates, and what counts as an allowable delay;
• the notices on the right to cancel and on mechanics liens.

Add the lines that are specific to cooling: the Manual J size, whether the Title 24 duct test and HERS verification are included, the refrigerant, and the labor and parts warranty terms. The quote comparison tool lists each one so you can line three quotes up.

Your right to cancel

A signed home improvement contract can usually be cancelled within three business days; CSLB says the notice has to be mailed before midnight of the third day. If you are 65 or older, CSLB's guide for seniors gives five business days. The window does not apply to a contract you negotiated at the contractor's own place of business, or to a service and repair contract of $750 or less for work needed right away.

Refrigerant certification is separate

The CSLB license covers the business. The technicians who connect the line set and charge the system also need EPA Section 608 certification, a federal requirement for anyone who opens a refrigerant circuit. It is a personal card, not a company license, so it will not show on the CSLB record. It is fair to ask whether the crew installing your system holds it, especially now that new equipment uses A2L refrigerants such as R-454B; see the R-454B guide.

A worked check

Say a quote arrives from "Valley Air Pros" with license number 1012345 on the letterhead (a made-up example). In about three minutes:

1. Search the number, not the name. The record should show the same business name. If it shows "Valley Air Pros Inc." while the quote says "Valley Air Pros LLC", ask why; they are different legal entities.
2. Read the classification line. You want C-20. Under Business and Professions Code § 7057, a B (general building) contractor can take an HVAC-only job only if they also hold the C-20 or subcontract the work to someone who does, so a B-only contractor quoting a standalone AC swap should say who is doing the install.
3. Open the bond and workers' comp tabs. Both should be current. An exemption from workers' comp means the contractor says they have no employees; if a crew of three shows up, that does not add up.
4. Scroll to the bottom for disciplinary actions. CSLB shows public complaints that resulted in legal action. One old item is not disqualifying on its own; a recent pattern is.
5. Write the check date on the quote. Licenses lapse. If the job starts a month later, run it again.

Sources

• California Code of Regulations, Title 16, § 832.20, via Cornell LII (retrieved 2026-09-29)
• CSLB press release #24-21, "Handyperson Exemption to Increase to $1,000 in 2025" (AB 2622) (retrieved 2026-09-29)
• CSLB, "Bond Requirements" (retrieved 2026-09-29)
• CSLB, Check a License (retrieved 2026-09-29)
• CSLB, "What Should I Look for in a Contract and Binding Agreements?" (retrieved 2026-10-26)
• CSLB, "What Seniors Should Know Before Hiring a Contractor" (retrieved 2026-10-26)
• U.S. EPA, Section 608 Technician Certification (retrieved 2026-10-26)

Questions

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