Published 3 October 2026 by Tarun Kumar, Founder and CEO, DataGardener. Companies House API coverage is taken from the official Companies House developer documentation.
The short version
A Companies House MCP server answers questions about the register: who a company is, who runs it, what it has filed and what it owes on registered charges. It does this one company at a time. DataGardener MCP answers questions that need the register plus everything joined to it: filed financial figures, public contracts, public spend, property, ownership and group structure, across the whole UK company population.
What a Companies House MCP server gives an agent
Open-source Companies House MCP servers wrap the Companies House public data API. That API covers:
- Company search and company profiles, including status, registered office and SIC codes
- Officers and their appointments, and disqualified officers
- Filing history, with links to the filed documents
- Registered charges
- Persons with significant control (PSC)
- Insolvency, exemptions, registers and UK establishments
For a single named company, this is useful, authoritative and free. If that is all your agent needs, a Companies House MCP server is a sensible choice.
Where it stops
- No financial figures. The API tells you that accounts were filed and where the document is. Turnover, profit, cash, debtors and net assets are not returned as fields, so an agent cannot compare or screen on them.
- One company at a time. The API is built for lookups by name or number. A question such as “which engineering SMEs in the West Midlands grew turnover two years running” would mean pulling every candidate one by one, within a per-key rate limit, and still having no financials to filter on.
- Only the register. Public contract awards, council and NHS payments, HM Land Registry ownership, shareholdings and group structures sit in other sources that a Companies House wrapper does not reach.
- You run it. Each deployment needs hosting, an API key per user or per server, and maintenance as the API changes.
Side by side
| Question type | Companies House MCP | DataGardener MCP |
|---|---|---|
| Is this company active, and who are its directors? | Yes | Yes |
| Who controls it (PSC) and what charges are registered? | Yes | Yes, with lender and charge-age analysis |
| What were its turnover, cash and net assets over recent filings? | No, documents only | Yes, parsed from filed accounts |
| Which companies in a region and sector match financial conditions? | No | Yes, across the whole population |
| Has it won public contracts, and from which buyers? | No | Yes, from Contracts Finder and Find a Tender notices |
| How much have councils or NHS bodies paid it? | No | Yes, from published spend data |
| What land or property does it own? | No | Yes, from HM Land Registry corporate ownership |
| Who are its shareholders and ultimate parent? | PSC only | Yes, shareholdings and group structure |
| Source and date shown with each record | Depends on the implementation | Yes, by design |
| Cost | Free API; you host and maintain | Paid, metered per record; operated by DataGardener |
How to choose
- Choose a Companies House MCP server if your agent checks register facts about companies it already knows by name, and you are happy to host it.
- Choose DataGardener MCP if your agent needs to find companies, compare them on financials, or connect a company to its contracts, spend, property and owners. This is the case for most lending, procurement, supplier due diligence and market research work.
- Use both if you want a free register check alongside the wider intelligence. They work side by side in the same agent.
A note on the underlying data
Companies House data is public and published under the Open Government Licence. DataGardener uses it too. The difference is not access to the register; it is what has been joined to it, parsed from it and made queryable at population scale, with the source and date kept on every record.