Where every record comes from

Primary sources, not an aggregator

Records come from files the licensing boards themselves publish: roster extracts, open-data datasets, and authenticated agency download portals. We do not buy a third-party dataset and resell it, and we do not infer a license from a directory listing or a provider's own claim about themselves.

That distinction matters most for the opposite case. Provider records in the federal NPPES registry contain license numbers self-reported to CMS, and NPPES has no mechanism to validate them against any board. We treat those as claims to be checked, never as verification - which is why the cross-reference endpoint reports confirmed, name_mismatch and unresolved as distinct outcomes instead of collapsing them into a yes.

Provenance on every response

Each verification returns the evidence alongside the answer, so it can be filed rather than trusted:

"provenance": {
  "source":       "co-dept-regulatory-agencies",
  "source_url":   "https://data.colorado.gov/d/7s5z-vewr",
  "method":       "public_csv",
  "data_as_of":   "2026-10-26T23:41:36.038Z",
  "retrieved_at": "2026-08-16T00:52:22Z",
  "attribution":  null
}

• source_url - the government file itself. You can open it and check us.
• data_as_of - when that file was last successfully refreshed, not when you called us. A cached answer never pretends to be newer than its source.
• attribution - carried where a board requires it. Illinois roster data, for example, ships under ODbL.

Authenticated sources

Not every board publishes open data. Some of the states we cover release their rosters only to credentialed accounts through an agency portal, and we ingest those under the access the agency issues us rather than from a public URL. Records sourced that way carry the same provenance block as any other, naming the issuing board. It is the reason coverage in those states exists at all, and it is not something a competitor mirroring open-data portals reproduces by pointing at a link.

Refresh cadence and honesty about staleness

Sources refresh on their own schedules - daily for most open-data feeds, weekly where the board publishes weekly. A source that fails three consecutive times is marked broken and stops being scheduled; the previous snapshot keeps serving so a lookup degrades to stale but dated rather than silently disappearing. Its data_as_of stops advancing, which is how you can tell.

Ingests replace a source's snapshot wholesale, guarded by a sanity floor: a download that returns less than half the previous run's row count is rejected rather than applied, so a truncated file cannot quietly wipe a roster.

What we do not claim

• not_found is not proof of absence. It means the number is not in the roster we hold for that profession and state, as of that file's date.
• not_supported is about us, not the person. It means we hold no roster for that combination. It must never be presented as a finding about a license holder.
• We are not a consumer reporting agency. Results are not consumer reports and may not be used for employment, credit, insurance, housing or licensing eligibility decisions. See the Terms of Service.
• Boards are the final authority. Where the consequence of being wrong is material, confirm against the board directly - the source_url in every response takes you there.
• Not every source publishes a status. Some boards publish only currently-valid licences; a few publish no status column at all, just an expiry date. On those we report validity from the date and label the source accordingly. Absence from such a file is not evidence of discipline.
• A licence number can match more than one person. Several boards run independent numbering series per licence class, so the same number can belong to a registered nurse and to a vocational nurse. We return every match under other_matches, holder name included, rather than silently picking one.
• A state's coverage can be limited to one licence class. Where a board issues several credentials on independent numbering series that overlap, we mirror the primary practice licence rather than folding series that collide. California is the current example: we hold Registered Nurse licences, not vocational-nurse or advanced-practice certificates. Every response names the class it matched in license_type - check it before treating a result as the credential you asked about.

Current sources

Every profession and state we cover, with the backing board and last refresh, is listed on the coverage page and returned programmatically by GET /api/v1/verify/coverage.