Data sources
Every business in our directory traces back to one of these public registries or to an owner-submitted listing. We never invent rows. Each section below explains what the source is, exactly which records we pull, and how often we refresh.
CSLB C-36 Plumbing Contractor registry
State or local licensing authorityWhat it is. The Contractors State License Board (CSLB) licenses every contracting business in California under the Contractors State License Law (Cal. Bus. & Prof. Code section 7000 et seq.). Plumbing work of $1,000 or more (labor + materials) requires an active C-36 Plumbing Contractor classification. Each license record carries the business name, license number, classifications, bond, and workers'-compensation status -- all publicly checkable through the CSLB license lookup.
How we use it. We import active C-36 licensed contractors and tag them with source_name='CA CSLB' so they can be filtered or removed in bulk if the licensing relationship ever changes. Cert chips on each profile name the specific CSLB classification held.
Refresh cadence. Re-pulled quarterly; on-demand when a license lapses.
Citation: Contractors State License Board (www.cslb.ca.gov)
California Open Data Portal license datasets
State or local licensing authorityWhat it is. The State of California open-data portal publishes state licensing datasets -- including CSLB contractor license records -- through public APIs. Records include the licensee name, license number, classification, and current status.
How we use it. Pulled from the public endpoint filtered to the C-36 plumbing classification with ACTIVE status. Tagged with source_name='California Open Data Portal' and deduped against the CSLB roster by name + license number.
Refresh cadence. Re-pulled weekly.
Citation: California Open Data Portal (data.ca.gov)
Municipal permitting records
State or local licensing authorityWhat it is. Large California cities (Los Angeles, San Diego, San Jose, San Francisco, Sacramento and others) publish contractor and permit records through their building departments -- for example the Los Angeles Department of Building and Safety. A contractor pulling plumbing permits inside city limits appears in these public rolls.
How we use it. Used as a company-level cross-check and tagged with source_name='Municipal Registration' where a city roll is the primary source. Statewide CA coverage flows through CA CSLB.
Refresh cadence. Re-pulled quarterly.
Citation: City building departments (e.g. ladbs.org)
CAPHCC member directory
Professional associationWhat it is. The California Plumbing-Heating-Cooling Contractors Association (CAPHCC) is the state's leading plumbing trade association. Its public member directory lists member firms that invest in apprenticeship, training, and code-compliance standards.
How we use it. Member firms are matched against listings we already have and tagged with the 'PHCC Member' credential. We do not auto-create listings from association membership alone.
Refresh cadence. Re-pulled quarterly.
Citation: California PHCC (caphcc.org)
California Secretary of State business registry
State or local licensing authorityWhat it is. The California Secretary of State publishes the public business-entity database -- corporations and LLCs registered to do business in California, with formation date and good-standing status.
How we use it. Used during verification to confirm a claimed plumbing business is a registered California entity in good standing. We do not import listings from this source; it is a cross-check only.
Refresh cadence. Checked at verification time.
Citation: California Secretary of State bizfile (bizfileonline.sos.ca.gov)
Want to see our verification process step-by-step? Read How we verify. For our editorial neutrality, dispute, and removal policies, read Trust standards.
If you represent one of these registries and have feedback on how we cite or use your data, please contact us.