Getting started

Get an API key

Register at developer.company-information.service.gov.uk — free, takes about 30 seconds. You'll need the key for both the CLI and the MCP server.

CLI

Install the ch binary globally:

npm install -g companies-house-cli
ch config set-key your-key-here

Test it:

ch search "Anthropic"
ch profile 14604577
ch report 14604577

Full CLI reference in CLI →.

MCP server

The MCP server connects AI assistants (Claude, Cursor, Zed) to live Companies House data.

The quickest setup — add this to your client's config:

{
  "mcpServers": {
    "companies-house": {
      "command": "npx",
      "args": ["-y", "companies-house-mcp"],
      "env": {
        "COMPANIES_HOUSE_API_KEY": "your-key-here"
      }
    }
  }
}

Client-specific instructions in MCP setup →.

Company numbers

Companies House identifies companies by number — an 8-digit, zero-padded string:

• 14604577 — Anthropic Ltd
• 00445790 — Marks and Spencer
• SC123456 — Scottish companies use the SC prefix

If you only know the company name, use ch search or the search_companies tool to find the number first.