Legal entities controlling a British company

The British PSC register is public, and Sirenic serves the part of it that describes legal entities: the parent company that owns or votes, with its register identification and the published bands. Natural persons exercising control are counted, never named since 19 September 2026: on 3 September 2026 the Court of Justice of the European Union ruled (C-798/24) that shareholder data published online without any access condition breaches the GDPR. The official statements — including “no identifiable controller” — are still served, which is itself information.

See a real response (free) Get the quote for /v1/eu/entreprise/GB/{company_number}/beneficiaires-effectifs

What the route returns

Catalogue description, exactly as agents read it:

UK persons with significant control (PSC register) live from Companies House, for KYB and group-structure checks: LEGAL-ENTITY controllers only (corporate entities, legal persons) with natures of control (ownership/voting bands), notification dates and register identification, plus official PSC statements. Natural-person controllers are COUNTED, never named (GDPR, CJEU C-798/24, since 2026-09-19). Ceased PSCs excluded by default (inclure_cesses=true adds them).

Expected identifier

British company number.

A wrongly formatted identifier in the path returns 400 and is not billed — but it costs you a round trip. It is the leading cause of failed calls on the foreign routes. A search parameter, by contrast, is cleaned up: unsupported characters are stripped and the usable query is served.

Extract from a genuinely paid response

Dated snapshot from 2026-07-29, truncated to one item per array. It is not live data. The full extract is served free of charge from the samples surface, and the schema from the OpenAPI document.

{
 "pays": "GB",
 "company_number": "00446915",
 "nombre_actifs": 1,
 "nombre_cesses": 0,
 "exemption_possible": false,
 "personnes_physiques_omises": {
  "actifs": 0,
  "cesses": 0
 },
 "autres_types_omis": {
  "actifs": 0,
  "cesses": 0
 },
 "beneficiaires": [
  {
   "type": "entite",
   "nom": "Bp International Limited",
   "notifie_le": "2016-04-06",
   "natures_de_controle": [
    "ownership-of-shares-75-to-100-percent"
   ],
   "identification": {
    "forme_juridique": "Limited By Shares",
    "registre": "Companies House",
    "numero_registre": "00542515"
   }
  }
 ],
 "declarations": [],
 "source": "Companies House (api.company-information.service.gov.uk). Contains public sector information licensed under the Open Government Licence v3.0 (Companies House).",
 "data_freshness": "Companies House temps réel (cache 24 h)"
}

Price and billing

Price: $0.02. The authoritative amount is the one in the 402 quote returned by the route itself — not this text, which derives from the same grid but is still just a page.

An error response cancels the payment: a 400, 404 or 503 is never billed. An upstream outage closes the route with a 503 rather than serving a degraded response.

Calling the route

# 1. Le devis, sans rien payer : la route répond 402 avec son montant
curl -i https://api.sirenic.eu/v1/eu/entreprise/GB/{company_number}/beneficiaires-effectifs

# 2. L'appel réglé — le client x402 paie le devis et rejoue la requête
npx x402-fetch https://api.sirenic.eu/v1/eu/entreprise/GB/{company_number}/beneficiaires-effectifs

# 3. Ou en MCP, dans Claude Code / Cursor / un agent
claude mcp add --transport http sirenic https://api.sirenic.eu/mcp

What this route does not do

Ceased controllers are excluded by default: add inclure_cesses=true to get them with their cessation date. Natural persons are never served: personnes_physiques_omises gives their number, and the public Companies House register remains available at the source.

Neighbouring routes

/v1/eu/entreprise/GB/{company_number}/dirigeants — $0.01
/v1/entreprise/{siren}/capital — $0.35

How you pay

Every route is paid per call, in USDC or EURC on the Base network, over the x402 protocol: no account to create, no API key, no subscription. The first call returns a 402 quote your client settles, then replays the call. A failed call is never billed.

Would you rather have a euro invoice and prepaid credits? That is in preparation, and we will not announce a date until it is open. Write to contact@sirenic.eu and we will let you know when it opens.

Paid responses are Ed25519-signed: you can later prove what was served to you, and when. The whole catalogue is free to read in the OpenAPI document and in llms.txt.

One call, end to end

# Client x402 (npm) — le devis 402 est réglé et l'appel rejoué automatiquement
npx x402-fetch https://api.sirenic.eu/v1/entreprise/552032534

# Ou en MCP, dans Claude Code / Cursor
claude mcp add --transport http sirenic https://api.sirenic.eu/mcp

Routes used and pricing

Route	Price	Sample	What it returns
`/v1/eu/entreprise/GB/{company_number}/beneficiaires-effectifs`	$0.02	free sample	UK persons with significant control (PSC register) live from Companies House, for KYB and group-structure checks: LEGAL-ENTITY controllers only (corporate entities, legal persons) with natures of control (ownership/voting bands), notification dates and register identification, plus official PSC statements. Natural-person controllers are COUNTED, never named (GDPR, CJEU C-798/24, since 2026-09-19). Ceased PSCs excluded by default (inclure_cesses=true adds them).

Take it further

No account to create, no key to request: the first step is free and shows you exactly what you would be buying.

See a real response (free) Get the quote for /v1/eu/entreprise/GB/{company_number}/beneficiaires-effectifs Get notified about euro packs