# 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.

## 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](https://api.sirenic.eu/exemples/), 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](mailto:contact@sirenic.eu?subject=Euro%20credit%20packs) 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](https://api.sirenic.eu/openapi.json) and in [llms.txt](https://api.sirenic.eu/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](https://api.sirenic.eu/exemples/eu-entreprise-GB-company_number-beneficiaires-effectifs.json) | 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

- [See a real response (free)](https://api.sirenic.eu/exemples/eu-entreprise-GB-company_number-beneficiaires-effectifs.json)
- [Get the quote for /v1/eu/entreprise/GB/{company_number}/beneficiaires-effectifs](https://api.sirenic.eu/v1/eu/entreprise/GB/{company_number}/beneficiaires-effectifs)
- [Get notified about euro packs](mailto:contact@sirenic.eu?subject=Euro%20credit%20packs)

## Read next

- [Identifying who controls a company, without naming a natural person](https://api.sirenic.eu/en/use-cases/beneficial-owners-what-api-can-still-serve-2026)


Volume figures on this page were measured in our database on 2026-08-19. They are dated snapshots, not live counters.

---

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