STATE LICENSE
RequiredContractors State License Board (CSLB)
The Contractors State License Board licenses plumbing as classification C-36. There is no separate journeyman plumber licence in California and no state-issued individual plumber card — the credential attaches to the contracting business through its qualifying individual, who must show four years of journey-level experience in the trade within the last ten years.
The C-36 scope is defined by function rather than by pipe: safe water supply and proper disposal of fluid waste, plus gas piping, medical and industrial gas systems, water heating equipment, and safety devices such as gas earthquake valves and backflow preventers. The one boundary worth memorising is that C-36 covers 'all gas appliances, flues and gas connections for all systems including suspended space heating units' but expressly does not include forced warm air units — those are C-20.
The state sets the license floor; the county or city permit office controls filing, inspections, and local rules wherever the job site sits.
Cities and counties do not license plumbers — that is exclusively state. They issue plumbing permits, and B&P § 7031.5 requires the permit applicant to file a signed statement giving the license number or the exemption basis. Local water purveyors separately administer cross-connection and backflow-prevention testing programmes, and many require a separately certified tester for annual backflow assembly tests.
The local offices section below names the exact permit desk for every California county on file.
Each row names the issuing authority, cost, timeline, citation, and status behind the requirement — verified against the official source.
Published fees from the issuing authorities, as of September 2026. Local permit fees vary by project and jurisdiction — the basis is stated where a flat number does not exist.
An extra classification requested with the original application is $150; requested later under B&P § 7059 it is $230. No additional license fee is charged for the extra classification itself.
SB 1455 moved the all-classification workers' compensation mandate from January 1, 2026 to January 1, 2028. A C-36 sole owner with no employees may still file the exemption certificate today.
The C-36 scope covers all gas appliances and gas connections 'including suspended space heating units' but expressly excludes forced warm air units. Furnace work belongs to C-20.
A practical sequence for a new plumbing contractor in California. Actual agency processing times are noted in the ledger above.
Each item names the issuing authority, cycle, and citation.
Statutory consequences with their citations — not estimates, not “commonly cited” guesses.
A misdemeanor. First conviction: up to $5,000 and/or six months in county jail. Second: a fine of 20% of the contract price or aggregate payments, minimum $5,000, plus at least 90 days in jail.
California's rule is unusually harsh: not only can an unlicensed contractor never sue for payment, the customer may affirmatively recover all compensation already paid, regardless of how good the work was.
Signing the permit statement claiming a licence or an exemption you do not have carries its own civil penalty.
Inside city limits, the city office listed here issues the permit; the county office serves unincorporated areas. Every office links to its official page.
Every fact in this file was checked against these official sources on September 2026.
Pending verification: Whether California requires a state-level backflow prevention assembly tester certification, or leaves tester certification entirely to local water purveyors — not confirmed on a state source · The dollar cost of the C-36 trade examination; B&P § 7137(a)(2) sets exam fees at the administering organization's actual cost · Local plumbing permit fee ranges — every California jurisdiction sets its own schedule
General information, not legal advice. Always confirm requirements, deadlines, and forms with the issuing authority before filing or contracting.
Store licenses, permits, policies, and renewal dates in one place.