Be the first to get access to new connectors. Get early access →
ConnectorBay Early access

Companies House (BYOK) — connector documentation

  • MCP endpoint: https://byok-companieshouse.connectorbay.com/mcp
  • REST API: POST https://byok-companieshouse.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://byok-companieshouse.connectorbay.com/openapi.json
  • Transport: Streamable HTTP, stateless, MCP specification 2025-06-18 or later
  • Authentication: your own Companies House Companies House API key, sent in the X-Upstream-Key header of every request (never stored, logged or cached)
  • Health: https://byok-companieshouse.connectorbay.com/health · Tool schemas: https://byok-companieshouse.connectorbay.com/tools.json
  • Publisher: Unify Dynamics LLC · connectorbay.com/byok-companieshouse · agent@connectorbay.com

What Companies House (BYOK) is for

Companies House (BYOK) lets an AI assistant read your own Companies House data through the Companies House API with a key you supply (Companies House API key). Read-only: 7 tools (search_companies, get_company, list_company_officers, list_filing_history, list_company_charges, search_officers, list_officer_appointments). The BYOK key travels with each request, is used for that one call only and is never stored, logged or cached; it is only ever sent to api.company-information.service.gov.uk. Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by Companies House. Companies House and its logos are trademarks of their owners and are used only to say which service the connector works with.

Ask your assistant things like:

  • "Find UK companies called Acme Widgets"
  • "Show the company profile of 00000006"
  • "Who are the directors of company 00000006?"
  • "What has company 00000006 filed recently?"
  • "Does company 00000006 have any outstanding charges?"
  • "Find company officers named Jane Example"

What it does

  • search_companies: Search UK registered companies by name or number; returns company number, name, status, type, incorporation date and a short address.
  • get_company: Get a UK company profile by number: name, status, type, incorporation and cessation dates, SIC codes, registered office address, accounts and confirmation statement dates, and charge and insolvency flags.
  • list_company_officers: List the officers (directors, secretaries, members) of a company with role, appointment and resignation dates, nationality, occupation and country of residence. Addresses and birth dates are not returned by this connector.
  • list_filing_history: List a company's filing history (accounts, confirmation statements, officer changes ...) with date, category, type, description and links to the documents.
  • list_company_charges: List the charges (mortgages and security) registered against a company, with status, creation and satisfaction dates and who they are in favour of.
  • search_officers: Search company officers by name; returns the name, how many appointments they hold and links to their appointment lists. Birth dates are not returned by this connector.
  • list_officer_appointments: List the company appointments of one officer by officer id (the id is in the officer's links from list_company_officers or search_officers): company name, number and status, role and dates.

BYOK key

You bring your own Companies House Companies House API key (https://developer.company-information.service.gov.uk/get-started). Your assistant sends it in the X-Upstream-Key header with each request. ConnectorBay uses it for that one call only: it is never stored, logged or cached, never shown in an answer, and it is only sent to api.company-information.service.gov.uk over https, with no redirects followed. Create a key with the fewest permissions the tools need (read-only if the provider offers it), and revoke it at the provider whenever you like.

Data sources

Live from the Companies House API (api.company-information.service.gov.uk) with a BYOK key; documentation: https://developer-specs.company-information.service.gov.uk/companies-house-public-data-api/reference. Endpoints checked against that documentation on 2026-10-16.

What it is not

Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by Companies House. Companies House and its logos are trademarks of their owners and are used only to say which service the connector works with. It is read-only: it never creates, changes, sends or deletes anything in your Companies House account.

Built for: Worldwide. Languages: English.