Companies House MCP server: connect UK company data to Claude, ChatGPT and Cursor

What an MCP server does for company research

The Model Context Protocol (MCP) is an open standard that lets AI assistants call external tools. With a Companies House MCP server connected, you can ask Claude "Is TESCONS LTD still trading and what were its net assets last year?" and the assistant calls a tool, reads the answer from real filings and cites it, instead of guessing from training data.

Typical jobs it handles well:

• Due diligence on a supplier or customer before signing: status, accounts due date, last balance sheet.
• Comparing two companies side by side.
• Building lead lists by financial signal: cash-rich, fast-growing or deteriorating companies.
• Keeping an eye on a list of companies and getting alerts when one is late, enters liquidation or reports negative net assets.

Connect in two minutes

1. Get a free key on the developer docs page (50 requests a month, no card).
2. Add the server to your client using one of the snippets below.
3. Ask a question that names a UK company or a company number.

claude.ai (web and mobile)

Settings, Connectors, Add custom connector, then paste:

https://data.globalmindsetmarketing.co.uk/mcp?key=YOUR_KEY

claude.ai custom connectors cannot send headers, so the key goes in the URL. Treat that URL as a secret.

Claude Code

claude mcp add --transport http uk-company-data https://data.globalmindsetmarketing.co.uk/mcp --header "Authorization: Bearer YOUR_KEY"

Cursor

Add to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "uk-company-data": {
      "url": "https://data.globalmindsetmarketing.co.uk/mcp",
      "headers": { "Authorization": "Bearer YOUR_KEY" }
    }
  }
}

Claude Desktop

Claude Desktop reaches remote servers through mcp-remote (needs Node.js). Add to claude_desktop_config.json:

{
  "mcpServers": {
    "uk-company-data": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://data.globalmindsetmarketing.co.uk/mcp", "--header", "Authorization: Bearer YOUR_KEY"]
    }
  }
}

ChatGPT and other clients

Any client that supports remote MCP over Streamable HTTP can use the same endpoint. Where a client cannot send an Authorization header, append ?key=YOUR_KEY to the URL.

Tools the server exposes

Example prompts

• "Find TESCO PLC and show its last three balance sheets."
• "Is company 10623966 up to date with its accounts? When are the next ones due?"
• "Compare SC316774 with 00590446 on cash, net assets and employees."
• "Add these 12 company numbers to my watchlist and tell me which ones need attention."
• "Which UK companies published new accounts in the last 7 days?"

What the data covers, and what it does not

• Register: every company on the Companies House register, refreshed monthly: name, status, type, incorporation date, registered office, SIC codes, accounts category and due dates.
• Financials: figures tagged in iXBRL accounts filed since 2008, as filed: total assets less current liabilities, net assets, cash, debtors, creditors, equity, employees and, where filed, turnover and profit.
• Not covered: accounts filed only as PDF or paper scans (common for large groups) are not in the iXBRL data. Officers and PSC details come from Companies House directly and are not yet part of this server.

Figures are what the company filed. They are not a credit rating.

Why not build your own server on the Companies House API?

You can, and for live officer or filing-history lookups the free Companies House API is the right source. The API does not return balance sheet figures as data, though: accounts come as documents. Getting numbers means downloading bulk iXBRL files, parsing tens of millions of documents and keeping them in sync daily. That is the part this server does for you. See Companies House API vs bulk data for the trade-offs.

FAQ

Is there an official Companies House MCP server?

Not as of October 2026. Companies House publishes a REST API and bulk data files. MCP servers for Companies House, including this one, are built by third parties on top of that open data.

Is the MCP server free?

Yes, up to 50 requests a month on the free key. API Pro is £39 a month for 5,000 requests and a 50-company watchlist.

Does it work with ChatGPT?

Yes, in any ChatGPT surface that supports remote MCP connectors over Streamable HTTP. Use the URL with ?key= if the client cannot send headers.

Where does the financial data come from?

From iXBRL accounts filed at Companies House and published in its free accounts bulk data, used under the Open Government Licence v3.0.

Sources: Companies House register and accounts data (Open Government Licence v3.0), legislation.gov.uk and GOV.UK guidance where linked. This page is general information, not legal, tax or credit advice. Spotted an error? Email info@globalmindsetmarketing.co.uk.