UK Companies House due diligence and KYB (Registrum)

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

UK Companies House due diligence: beneficial owners, directors, ECCTA, accounts. Hosted, no key

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Copy this into your MCP client config:

{
  "mcpServers": {
    "UK Companies House due diligence and KYB (Registrum)": {
      "url": "https://registrum.co.uk/api/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (11)

• search_company read-only

  Search for UK companies by name. Returns a list of matching companies with their company number, status, type, and registered address. Use this first when you only have a company name and need its company number.

  Parameters:

  • query (required) — string — Company name or keywords to search for
  • limit — integer — Maximum number of results to return (default 20)

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_company read-only

  Get an enriched profile for a UK company by its Companies House number. Returns name, status, type, incorporation date, registered address, SIC codes with descriptions, accounts status, confirmation statement status, and derived fields like company_age_years and accounts.overdue that are not available from the raw Companies House API.

  Parameters:

  • company_number (required) — string — Companies House company number, e.g. '00445790' for Tesco PLC. Numeric-only numbers should be zero-padded to 8 digits.

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_financials read-only

  Get structured financial data for a UK company, parsed from its iXBRL accounts filed at Companies House. Returns revenue, cost of sales, gross profit, operating profit, net profit, fixed assets, current assets, total equity, net assets, creditors, and average employees for the current and prior reporting year. Also includes accounts_type (full, abbreviated, micro, dormant or unknown) and a data_quality block indicating which fields were extracted and which were absent. period_end is the end of the accounting period the figures cover (the year the accounts end), NOT the date the accounts were filed; the filing date is data_quality.filed_on. Other data_quality fields: filing_type (Companies House form code: AA, AAMD or AC(NI)), period_end_source and accounts_type_source (how those two values were determined), and accounts_description_code (the verbatim Companies House code, e.g. unaudited-abridged, micro-entity). Unaudited-abridged, small and audit-exemption-subsidiary filings are abbreviated, not full, and carry no profit and loss (check has_profit_loss). accounts_type is unknown when it could not be determined; do not assume full. The response can be available: false with an unavailable_reason: image_pdf (accounts filed as a scanned PDF, common for large companies such as Tesco), no_ixbrl_filings (no digital filing), or dissolved. That means no figures could be extracted; it does not mean the company has no accounts. Cached for 7 days.

  Parameters:

  • company_number (required) — string — Companies House company number, e.g. '00445790' for Tesco PLC. Numeric-only numbers should be zero-padded to 8 digits.

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_directors read-only

  Get the current and past officers for a UK company. Despite the tool name, not every entry is a director: the list is the full officer register, so each entry carries an officer_role such as 'director', 'secretary', 'corporate-secretary' or 'llp-member', plus an is_board_director boolean that is false for secretaries. Report each person by their own officer_role - never describe the whole list as directors. Each officer includes name, officer_role, is_board_director, appointment date, resignation date (if applicable), nationality, occupation, month and year of birth, ECCTA verification status, and a list of other companies they are or were appointed to, each with its own officer_role. This gives you a full picture of an officer's corporate history in one call.

  Parameters:

  • company_number (required) — string — Companies House company number, e.g. '00445790' for Tesco PLC. Numeric-only numbers should be zero-padded to 8 digits.

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_compliance read-only

  Check a UK company's ECCTA identity-verification status - who has verified their identity with Companies House, who is still pending, and who is overdue. The Economic Crime and Corporate Transparency Act requires every director and PSC to verify their identity; enforcement begins 18 November 2026, after which unverified officers can block filings. Returns per-company counts (directors_total, directors_verified, directors_pending, directors_overdue) and the same for PSCs, plus unverified_persons with each person's name, role, status and their individual deadline. IMPORTANT: 'pending' means the deadline has not yet passed - it is NOT a failure and must not be reported as one. Only 'overdue' means a deadline was missed. Requires a Pro plan or above. Cached for 24 hours.

  Parameters:

  • company_number (required) — string — Companies House company number, e.g. '00445790' for Tesco PLC. Numeric-only numbers should be zero-padded to 8 digits.

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_psc read-only

  Get the PSC (Persons with Significant Control) register for a UK company. Returns individuals, corporate entities, and legal persons who own 25%+ of shares, hold 25%+ of voting rights, or have significant influence or control. Each PSC includes decoded control types in plain English (e.g. 'Owns 25-50% of shares' instead of raw codes). Individual PSCs also carry ECCTA identity verification: verification_status (verified, pending, overdue or unknown), identity_verified, identity_verified_on, and verification_deadline. pending means that person's deadline has not yet passed and is not a compliance failure; unknown means Companies House publishes no record for them, an absence of data rather than a breach. Only overdue means a deadline was missed. Corporate entity PSCs carry none of the verification fields. Their company_number is set only for a confirmed Companies House registration and is otherwise null, so never treat a null as a missing value to look up. What they filed is in registry_number and registry_name, and registry_is_companies_house says how to read it: true is a Companies House registration, null means a number was filed but cannot be tied to the UK register (e.g. a foreign registry), false means no number was filed. kind can be unknown for a PSC type we do not classify, with Companies House's verbatim string in kind_raw. Also detects PSC exemptions for listed PLCs. Cached for 24 hours.

  Parameters:

  • company_number (required) — string — Companies House company number, e.g. '00445790' for Tesco PLC. Numeric-only numbers should be zero-padded to 8 digits.

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_bundle read-only

  Get several views of one UK company in a single request: profile, ECCTA compliance, financials, PSCs and directors. Prefer this over calling get_company, get_compliance, get_financials, get_psc and get_directors separately - it returns the same data for one API call and one credit instead of five, and in a single round trip. Pass include to fetch only the sections you need; omit it to get all five. The profile is always returned. Partial results are normal and are not errors: any section can come back null when it is unavailable for that company or not included in the caller's plan - financials are null for a company that has filed no machine-readable accounts, and compliance requires a Pro plan. Report a null section as 'not available', never as a failed lookup or as an absence of the underlying fact. Only a missing company is an error, and that is a 404. Each section carries exactly what its own endpoint returns, including ECCTA verification_status on individuals, so the pending-versus-overdue rules apply here too.

  Parameters:

  • company_number (required) — string — Companies House company number, e.g. '00445790' for Tesco PLC. Numeric-only numbers should be zero-padded to 8 digits.
  • include — array — Sections to fetch. Omit for all five. Valid values: profile, compliance, financials, psc, directors. The profile is always included regardless.

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_psc_chain read-only

  Trace the full ownership chain for a UK company by recursively following corporate entity PSCs. Returns a tree showing who ultimately controls the company - natural persons (UBOs), foreign entities, or legal persons - along with why each branch terminated. Each node has a terminal_reason: natural_person, foreign_entity, legal_person, super_secure, unverified_registry, unknown_kind, depth_limit, not_found, cycle_detected, or psc_exempt. Two of those are easy to misread: unverified_registry means a registration number was filed but cannot be tied to the Companies House register (a foreign registry, or one we do not recognise), which is a finding about the ownership structure and not an error or an outage; unknown_kind means Companies House returned a PSC type we do not classify (kind is then unknown), with the raw value in kind_raw. Both are findings, not errors. A corporate node's company_number is set only for a confirmed Companies House registration, otherwise null; the number it filed is in registry_number with registry_name, and registry_is_companies_house is true (Companies House), null (a number was filed but cannot be tied to the UK register) or false (no number filed). ECCTA identity verification: every individual node, at any depth including the ultimate beneficial owners this chain exists to find, carries verification_status (verified, pending, overdue or unknown), identity_verified (true, false for overdue only, or null otherwise), identity_verified_on, and verification_deadline. IMPORTANT: pending means that person's own deadline has not yet passed - it is not a compliance failure and must not be reported as one. A status of unknown means Companies House publishes no record for them, which is an absence of data rather than a breach. Only overdue means a deadline was missed. Corporate, legal-person and super-secure nodes carry none of these fields, so never describe a company itself as having unverified identity. chain_metadata reports how many companies were resolved and the total API credit cost. Use this for KYB (Know Your Business) checks, AML screening, or any task requiring beneficial ownership beyond the immediate PSC layer.

  Parameters:

  • company_number (required) — string — Companies House company number, e.g. '00445790' for Tesco PLC. Numeric-only numbers should be zero-padded to 8 digits.
  • max_depth — integer — Maximum chain depth to traverse (1-10, default 5). Each level costs 1 upstream API call per corporate entity found.

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_network read-only

  Map the corporate network connected to a UK company via shared directors. Returns all companies connected through shared board members, up to the specified depth. Each connected company includes its name, number, status, and the directors it shares with the focal company. Useful for identifying corporate group structures, related party relationships, and director interlocks.

  Parameters:

  • company_number (required) — string — Companies House company number, e.g. '00445790' for Tesco PLC. Numeric-only numbers should be zero-padded to 8 digits.
  • depth — integer — Traversal depth: 1 = direct connections only, 2 = connections of connections (default 1). Depth 2 can return many results for large companies.

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search read-only

  Search UK companies at Companies House by name or keywords. Returns an object with a results array; each result has id (company:<number>, pass it to fetch), title (company name, number and status) and url (the company page on registrum.co.uk). Up to 10 results, in relevance order; results is empty when nothing matches. Use fetch on an id to read the company.

  Parameters:

  • query (required) — string — Company name or keywords to search for

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• fetch read-only

  Fetch one UK company by an id from search (company:<number>; a bare company number also works). Returns an object with id, title (company name), url (company page on registrum.co.uk), text (a plain-English summary followed by the full enriched profile as JSON: status, type, incorporation date, registered address, SIC codes, accounts and confirmation statement status) and metadata (company_number, company_status, company_type, source). Profile only; use get_bundle, get_psc, get_directors or get_financials for ownership, officers and accounts.

  Parameters:

  • id (required) — string — Company id from search, e.g. 'company:00445790'

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

Repository

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