Government — entry 089 of 90

UK Companies House

Verified Jul 2026

The public Companies House API exposes UK company registration data — profiles, officers, filing history, persons with significant control, and charges — free of charge. A live keyless request against `api.company-information.service.gov.uk` returned a `401` with `access-control-allow-origin: *`, confirming the read API is open to browser cross-origin calls. Despite the developer portal branding it "OAuth", the documented and primary way to call the read API is HTTP Basic auth with a free API key as the username; OAuth2 is a separate flow reserved for the restricted filing/account-linking scopes.

government-dataukcompany-registryopen-data
AuthenticationAPI KeySign up with the provider to obtain credentials.
HTTPSSupportedTraffic is encrypted in transit.
CORSEnabledCallable directly from browser JavaScript.
PricingFreeNo paid tier — free for the documented use case.
FormatsJSONResponses can be requested as JSON.

GreatAPIs Score

Score78out of 100
Authentication15/25API key required
Pricing20/20Free to use
Docs14/20Documentation URL provided
Formats9/15Single response format
Freshness20/20Verified within 6 months

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Scored 78 on greatapis.com
<a href="https://greatapis.com/api/uk-companies-house/"><img src="https://greatapis.com/badge/uk-companies-house.svg" alt="Scored 78 on greatapis.com"></a>

Auth quickstart

  1. Sign up with the provider to get an API key.
  2. Send it on every request as a headerAuthorization: <key>
  3. The exact header isn't documented — Authorization is a common default; confirm in the provider's docs.
Stored keyNo key stored

Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.