Licensing in California
California Contractors State License Board (CSLB) — C-20
California licenses HVAC through the CSLB's C-20 Warm-Air Heating, Ventilating, and Air-Conditioning classification, required for any project of $500 or more and needing four years of journey-level experience. Your site is built to show your CSLB C-20 license number plainly, because California homeowners verify it on the CSLB site before they book.