Look up the license
California contractors are licensed by the Contractors State License Board (CSLB). Its website lets you look up any license by number, business name or personal name. HVAC work is typically done under the C-20 classification for warm-air heating, ventilating and air-conditioning contractors.
- Status: active, with no suspensions.
- Classification: C-20 for HVAC work.
- Bonds and workers' compensation coverage on file.
- Business name and address that match the quote.
- Any disciplinary history or complaints.
The $1,000 rule
Since January 1, 2025, California lets unlicensed people do jobs under $1,000 (up from $500), but only if they don't hire workers and the job doesn't need a building permit. An HVAC system replacement needs a permit, so it isn't small-job work regardless of price.
Down payments
The CSLB cautions that a down payment on a home improvement project should not exceed 10 percent of the contract price, and later payments shouldn't run ahead of the work done or materials delivered. A demand for half up front is a reason to slow down.
Beyond the license
A license is the floor, not a recommendation. Ask who will pull the permit, whether HERS testing is included, and for a written load calculation. Our vetting standards explain what else we look for.
Keep reading
Looking for city-specific rules? See our SoCal city guides.
Sources
Last checked October 2026.