UK Due Diligence

uk-due-diligence-mcp

Official-source UK due-diligence data for AI agents.

Search Companies House, Charity Commission, The Gazette, HMLR price-paid data and HMRC VAT records, plus screen names against the OFSI, OFAC, EU and UN sanctions lists. Exposes atomic MCP tools for company ownership, officers, cross-company appointment history, secured charges, insolvency notices and related registry evidence — the consuming agent decides how to investigate, not the server.

Every data source is a legally-mandated register with a free official API. Zero paywalls.

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Data sources

Register	API	Auth	Coverage
Companies House	api.company-information.service.gov.uk	API key (free)	UK-wide
Charity Commission	api.charitycommission.gov.uk	API key (free)	England & Wales
HMLR Land Registry	landregistry.data.gov.uk (SPARQL)	None	England & Wales
The Gazette	thegazette.co.uk (Linked Data)	None (read)	UK-wide
HMRC VAT	api.service.hmrc.gov.uk	OAuth2 client credentials	UK-wide
OFSI / OFAC / EU / UN sanctions	consolidated list files	None	International

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Quick start

Hosted (no install)

{
  "mcpServers": {
    "uk-due-diligence": {
      "type": "http",
      "url": "https://uk-due-diligence-mcp.fly.dev/mcp"
    }
  }
}

Local (uvx)

{
  "mcpServers": {
    "uk-due-diligence": {
      "type": "stdio",
      "command": "uvx",
      "args": ["uk-due-diligence-mcp"]
    }
  }
}

See Configuration for the environment variables it needs.

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Tools

Companies House

Tool	Description
company_search	Search by name/keyword, filter by status/type
company_profile	Status, filing compliance, registered address, has_charges summary
company_officers	Directors/secretaries; each carries an officer_id
company_psc	Beneficial owners, PSC chain, overseas-corporate-PSC flag
officer_appointments	Full appointment history for a person by officer_id — including dissolved or insolvent companies not named anywhere else
company_charges	Complete secured-charge history: status, dates, secured parties, what each charge covers
disqualified_search	Search disqualified directors by name
disqualified_profile	Full disqualification record: period, Act, associated companies

Charity Commission

Tool	Description
charity_search	Search by name, filter by registration status
charity_profile	Full record: trustees, income/expenditure, governing document

HMLR Land Registry

Tool	Description
land_title_search	Price Paid Index sale transactions by postcode — not title ownership (see Limitations)

The Gazette

Tool	Description
gazette_insolvency	Corporate insolvency notices across the Gazette's notice-code taxonomy (codes 2401-2465)
gazette_notice	Full legal wording of a specific notice

HMRC / Sanctions

Tool	Description
vat_validate	Trading name + address as registered for VAT
sanctions_screen	Screen a name against the OFSI/OFAC/EU/UN consolidated lists

Cross-register

Tool	Description
search	Fan-out search across all registers — returns IDs (for ChatGPT deep research)
fetch	Fetch a structured record by ID returned from search

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Examples

Resolve "TAS Engineering" to a company number and check whether it has any outstanding charges.

→ company_search to find the company number, then company_charges for the full secured-debt picture (not just the has_charges summary).

Has Gareth Davies (director of company 06333469) been connected to any other companies, including ones that no longer exist?

→ company_officers to get his officer_id, then officer_appointments to surface every company he's held an appointment at, current or historic.

Is "MEL Precision Limited" in the middle of insolvency proceedings, and what does that actually mean legally?

→ gazette_insolvency to find the notices, then gazette_notice to read the full legal wording before drawing conclusions from the notice label alone.

Screen "Acme Trading Ltd" and its officers against sanctions lists.

→ company_officers for the officer names, then sanctions_screen against the company name and each officer.

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Limitations

Things worth knowing before trusting output:

• land_title_search returns Price Paid transactions, not ownership. It does not return current proprietor/title data — HMLR's Price Paid Index only records historic sale transactions.
• Sanctions screening is exact/alias matching, not compliance clearance. A company/entity legal name matches reliably; person names with transliteration variants may not. An empty result is not a guarantee of clearance, and a hit on a common name may need disambiguation.
• has_charges: null means the check could not be confidently completed — a charges-endpoint outage, or a charge with an unrecognized status. Treat it as unresolved, not as "no charges."
• officer_appointments returns historical relationships. Companies House doesn't auto-resign a director when a company enters insolvency — check company_status on each appointment, not just resigned_on.
• Official-source data can be incomplete or delayed. These are the same registers a human would check, with the same latency and gaps.

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Configuration

Variable	Required for	Where to get it
CH_API_KEY	All Companies House tools	developer.company-information.service.gov.uk — free
CHARITY_API_KEY	Charity Commission tools	api-portal.charitycommission.gov.uk — free
HMRC_CLIENT_ID / HMRC_CLIENT_SECRET	vat_validate	HMRC Developer Hub (developer.service.hmrc.gov.uk) — free, OAuth2 client-credentials app
HMRC_ENV	vat_validate (optional)	sandbox or production — defaults to production

HMLR, The Gazette, and the sanctions lists require no credentials.

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Project structure

uk-due-diligence-mcp/
├── server.py           # FastMCP init, tool/resource registration, transport config
├── companies_house.py  # company_search/profile/officers/psc, officer_appointments, company_charges
├── disqualified.py     # disqualified_search, disqualified_profile
├── charity.py          # charity_search, charity_profile
├── land_registry.py    # land_title_search (SPARQL Price Paid Index)
├── gazette.py          # gazette_insolvency, gazette_notice
├── hmrc_vat.py         # vat_validate (OAuth2 client-credentials)
├── sanctions.py        # sanctions_screen (OFSI/OFAC/EU/UN consolidated lists)
├── search_fetch.py     # search, fetch (cross-register fan-out)
├── models.py           # Pydantic v2 output models
├── http_client.py      # Shared httpx clients, retry backoff, error formatting
├── fly.toml
├── Dockerfile
├── pyproject.toml
└── .env.example

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Licence

MIT