canonical: https://jentic.com/apis/registrum.co.uk/registrum

# Registrum API

The Registrum API returns enriched UK company intelligence built on the Companies House public API: company profiles, directors with their other appointments, persons with significant control, and structured financials parsed from iXBRL filings with current and prior year figures. It maps networks of companies connected through shared directors, resolves PSC ownership chains to ultimate beneficial owners, and produces ECCTA identity-verification compliance snapshots and full Know Your Business reports. Lookups can run singly, in bulk for up to 50 companies, or as async batches of up to 500, and webhooks notify you of events such as status_change or directors_changed. Responses are cached, with each one reporting whether it was served from cache and how many credits it used.

## For AI agents

Look up UK companies by name or company number, pull directors, PSCs, filed financials, ownership chains, and KYB reports, and subscribe to webhook alerts on company changes.

## Scope

Does not file documents with Companies House, cover companies outside the UK register, or run credit scoring. Use for UK company profiles, officers, ownership, financials, and change alerts only.

## Capabilities

- Search UK companies by name with fuzzy matching via GET `/v1/search`, optionally returning enriched profiles with enrich=true
- Pull structured financials from filed iXBRL accounts, with current and prior year figures, for a company number
- Map companies connected through shared directors at depth 1 or 2 with GET `/v1/company/{company_number}/network`
- Resolve persons with significant control up the ownership chain to ultimate beneficial owners with max_depth
- Generate a full Know Your Business report or an ECCTA identity verification compliance snapshot for a company
- Enrich up to 50 companies in one call with POST `/v1/enrich`, or queue up to 500 with POST `/v1/batch` and poll the batch_id
- Subscribe a webhook url to events such as status_change, accounts_overdue, and pscs_changed for a list of company_numbers

## Use cases

### KYB research agent through Jentic

An onboarding agent vetting a new UK supplier needs company facts without a developer wiring X-API-Key handling, credit tracking, and plan-gated errors by hand. Through Jentic the agent searches for 'run a KYB check on a UK company', loads GET `/v1/company/{company_number}/kyb-report`, and calls it with the company number it found via GET `/v1/search.` It then reads GET `/v1/company/{company_number}/psc/chain` to name the ultimate beneficial owners in its summary.

Example prompt: Call GET `/v1/search` with q 'tesco', take the company_number 00445790, then GET `/v1/company/00445790/kyb-report` and GET `/v1/company/00445790/psc/chain` with max_depth 3

### Financial screening from filed accounts

Credit and sales teams screening UK companies want numbers rather than PDFs. GET `/v1/company/{company_number}/financials` returns parsed iXBRL filings as JSON with current and prior year figures, cached for 90 days. GET `/v1/company/{company_number}/bundle` returns profile, compliance, financials, psc, and directors sections in one request when a full company page is needed.

Example prompt: Call GET `/v1/company/{company_number}/bundle` with include 'financials,directors' and report the change in turnover between the current and prior year

### Director network investigation

Fraud and compliance analysts look for related entities behind a company. GET `/v1/company/{company_number}/directors` returns each director's other appointments, and GET `/v1/company/{company_number}/network` maps companies sharing directors at depth 1, or at depth 2 on Pro and Enterprise plans, capped at 30 connected companies.

Example prompt: Call GET `/v1/company/{company_number}/network` with depth 1 and list connected companies whose status is dissolved

### Portfolio monitoring with webhooks

Lenders and account managers tracking a book of UK companies can be told when something changes. POST `/v1/webhooks` takes a url, up to 50 company_numbers, and events such as status_change, accounts_overdue, confirmation_overdue, directors_changed, pscs_changed, company_updated, and compliance_risk_changed. For an initial backfill, POST `/v1/batch` queues up to 500 companies and GET `/v1/batch/{batch_id}` returns status and results.

Example prompt: POST `/v1/webhooks` with url 'https://example.com/hooks/registrum', company_numbers ['00445790','SC123456'], and events ['status_change','accounts_overdue']

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| GET | `/v1/search` | Search companies by name |
| GET | `/v1/company/{company_number}` | Get an enriched company profile |
| GET | `/v1/company/{company_number}/financials` | Get structured financials from filed accounts |
| GET | `/v1/company/{company_number}/psc/chain` | Resolve the PSC ownership chain |
| GET | `/v1/company/{company_number}/kyb-report` | Get a full KYB report |
| POST | `/v1/enrich` | Bulk enrich up to 50 companies |
| POST | `/v1/webhooks` | Create a webhook subscription |
| GET | `/v1/usage` | Read current usage and quota |

## Key resources

- **Search** — Fuzzy company-name search with optional enriched results
- **Company** — Enriched profile, bundle, directors, network, financials, PSC and PSC chain, compliance snapshot, and KYB report per company number
- **Bulk and batch** — Synchronous enrichment for up to 50 companies and async batches of up to 500 with polling
- **Webhooks** — Create, list, read, and delete subscriptions to company change events
- **Account** — Plans, usage and quota, trial start, feedback, and health checks

## AI readiness

This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use.

- **Score:** 69 / 100
- **Maturity:** AI-Aware
- **Dimensions:**
  - Foundational Compliance: 93 / 100
  - Developer Experience & Jentic Compatibility: 67 / 100
  - AI-Readiness & Agent Experience: 53 / 100
  - Agent Usability: 94 / 100
  - Security: 50 / 100
  - AI Discoverability: 91 / 100
- **View full report:** https://jentic.com/apis/registrum.co.uk/registrum/scorecard
- **How the score is calculated:** https://docs.jentic.com/reference/api-readiness-framework/overview/
- **More about the dimensions:** https://docs.jentic.com/reference/api-readiness-framework/specification/#dimensional-model-overview

### Score it yourself

Every API in the directory is allowlisted, so you can re-score it with no key required.

- **Score your own API:** https://jentic.com/scorecard.md
- **Scoring CLI agent skill:** https://github.com/jentic/jentic-api-scorecard/blob/main/skills/jentic-api-scorecard/SKILL.md

```sh
npx @jentic/api-scorecard-cli score <openapi-url>
```

## Why Jentic

- **Setup:** Wiring Registrum by hand means sending the X-API-Key header, tracking credits_used and credits_remaining, handling 403 PLAN_REQUIRED on plan-gated routes, and polling async batches. Through Jentic you install once, import Registrum from the API Directory, store the key once, and your agent calls it.
- **Permission scoping:** Registrum puts the company number in the URL path (`/v1/company/{company_number}/...`), so a rule can pin your agent to one company and the reads you pick. You choose the operations it may call, so actions like creating or deleting webhooks and submitting batches are not included unless you add them.
- **Credential handling:** Your Registrum API key is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'find the beneficial owners of a UK company' or 'get UK company financials', and Jentic returns the matching Registrum operation with its input schema so the agent calls the right endpoint without browsing the reference docs.

## Related APIs

- **Companies House API** — The official UK register that Registrum builds on, returning raw filings and records
- **OpenCorporates API** — Company records across many jurisdictions beyond the UK
- **Clearbit API** — Firmographic and web-domain enrichment for companies and contacts

## FAQ

### What authentication does the Registrum API use?

Per its OpenAPI spec, the Registrum API uses an API key sent in the X-API-Key header, in the form reg_live_ followed by the key. The health checks, GET `/v1/plans`, and POST `/v1/trial` endpoints need no credential. Through Jentic, the key is stored encrypted by your own Jentic One instance and injected at call time, so it never enters the agent's context.

### What are the rate limits for the Registrum API?

Registrum's API description lists tiers: Free at 50 calls a month, 15 a day, and 10 a minute burst; Web at 500 a month and 30 a minute; Pro at 4,000 a month and 100 a minute; and Enterprise unlimited with 150 a minute. New keys get full access for their first 60 days, and GET `/v1/plans` returns the live values while GET `/v1/usage` reports your remaining quota.

### Is there a Registrum MCP server?

Yes - Registrum links an MCP server, registrum-mcp, from its API documentation. You can also connect the Registrum API directly through Jentic: your agent gets the full 24-endpoint surface from the spec without loading another server's tool definitions into its context, your API key is injected at call time by your self-hosted instance instead of living in an MCP config, and your rules decide which operations the agent may call.

### Which Registrum features need a paid plan?

Network depth=2, PSC chain traversal, and ECCTA compliance monitoring are Pro and Enterprise features. Calls to these on Free or Web plans return 403 PLAN_REQUIRED with an upgrade_url, so an agent should handle that response rather than retry.

### How do I look up a UK company's directors through Jentic?

Search Jentic for 'get the directors of a UK company', load GET `/v1/company/{company_number}/directors`, and pass the Companies House number, for example 00445790. If you only have a name, call GET `/v1/search` with q first. To run it on your own infrastructure, install Jentic One from its GitHub repo.

### Can I limit what my agent is allowed to do with the Registrum API?

Yes. For a supplier check, write a rule that allows GET on `/v1/company/00445790/kyb-report` and `/v1/company/00445790/psc`, and the agent can read that one company's KYB report and controllers but cannot run bulk batches, create webhooks, or look up other companies. Every call it makes is logged.