Methodology: how the License Verified check works

Updated Oct 22, 2026 · current file: CSLB License Master, dated Oct 20, 2026 · by Carlos Morones

This page explains where every listing and number on the site comes from, what the green stamp checks, and what it doesn't. You can see the statistics this method produces, and how listings and ads work for the business side.

The data source

Everything starts with CSLB's License Master file, which CSLB publishes for free on its public data portal. It lists licenses that are current, or expired but still renewable. Cancelled and revoked licenses aren't in it. The copy on the site now is dated Oct 20, 2026 and has 245,368 records. We plan to refresh it weekly. Every page shows the file date it was built from. We don't edit, add to or "enhance" CSLB's records.

Definitions

• Active (233,184 licenses): primary status is CLEAR, the license isn't marked inactive, and its expiration date isn't before the file date.
• Listable (225,351): active, with a California mailing address and a city. These get listed. The rest are still in the license lookup.
• Trade: each trade page maps to a CSLB class, so "plumbers" means C-36 holders and "roofers" means C-39. B General Building licensees appear on the General Building & ADU pages, not single-trade pages.
• City pages: a trade gets a page in a city once at least 5 listable licensees have that mailing city. Lists are A–Z by business name, 100 per page. Pages with fewer than 10 listings are kept out of search engines for now (noindex) because they're thin.
• Listing pages: contractors in Los Angeles, San Diego, San Jose, Sacramento, San Francisco have their own pre-built page (19,933 of them). Everyone else's record loads on request from the same file.

How the numbers are counted

• Workers' comp "policy" means CSLB shows a workers' compensation insurance policy on file. Self-insured and employee-leasing coverage are counted separately where a page says so. "Exempt" means the licensee certified to CSLB that they have no employees.
• "Expiring within 90 days" means an expiration date on or before Jan 18, 2027 (90 days after the file date). "WC expiring within 30 days" uses the workers' comp policy expiration date the same way.
• License age is years from the original issue date to the file date. Medians are taken across the licenses on that page or table.
• Flags are counted when a license has any CSLB secondary status or a pending suspension date (more below).
• Shared names count exact business-name matches among listable licenses.
• Counts are recomputed every time the site is built, so a page's numbers always match the file date printed on it.

What the License Verified stamp checks

A listing gets the green stamp only when, in the file dated on the stamp, the license is active (as defined above) and carries no CSLB secondary status or pending suspension date. That's it. The stamp is a checked fact about one file on one date. It says nothing about the quality of anyone's work, their complaint history, or insurance beyond what CSLB records. CSLB's own Check a License page is real-time and shows legal actions, so check there before you sign.

How CSLB flags are shown

7,043 active licenses carry a CSLB flag, most often "WC Susp Pending" (4,153). Those listings don't get the green stamp. They show a neutral note instead, "Active — CSLB flag: …", with a plain-English version of CSLB's wording, and CSLB's exact text one hover or tap away. Where CSLB's abbreviation isn't clear enough to translate, we show CSLB's text in quotes. Flagged listings are also kept out of search engines until the flag clears. The translations we use:

Workers' comp context: CSLB requires C-8, C-20, C-22, C-39, D-49 licensees to carry workers' comp even with no employees (CSLB), so an "exempt" line on one of those classes is worth asking about.

Caveats

• Mailing city. City is the city on the contractor's CSLB mailing address. It isn't a service area, and it isn't always the legal city. In Los Angeles, 12,570 listable licensees in Los Angeles County use one of 45 neighborhood names inside the City of LA (Van Nuys, Sherman Oaks and so on), compared with 6,413 who use "Los Angeles." We match those names against Wikipedia's list of LA districts and neighborhoods, only for LA County records. Treat that as approximate: a mailing name isn't a boundary.
• Survivorship. Counts by issue year only include licenses that are still in the file. "Licenses issued in 2025" means issued in 2025 and still current or renewable on the file date.
• Permit valuations. The San Jose ADU page uses the valuation declared on city permits (497 ADU permits). That's the figure used for permit fees, not a contract price, and the city's file only has permits that are still active. Most of those valuations work out to one of two per-square-foot rates, so they track size more than price.
• Timing. A license can change the day after the file date. CSLB's site is always the current record.

Corrections and claims

If a listing is wrong, the fix almost always has to happen at CSLB, because we show CSLB's record as is. Once CSLB's file changes, the site picks it up on the next refresh. Contractors can claim their listing for free to add contact details. Claiming never changes the list order or the stamp. If you think we've counted something wrong, use the claim form's message box and we'll look at it.

Changelog

• Oct 22, 2026: CSLB-flagged licenses no longer get the green stamp. They show "Active — CSLB flag" with CSLB's wording. Added this page, the statistics page, city hubs and the San Jose ADU permit page. Trade pages with fewer than 10 listings are now noindex. File dated Oct 20, 2026.

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