Companies House API for AI-agent research

What the official source provides

Companies House publishes the authoritative public company register for incorporated UK companies. Its official API documentation covers company profiles, officers, filing history and related public resources.

The source can support:

• legal name, number, status and registered-office checks;
• current and resigned officer research;
• filing-history discovery;
• Persons with Significant Control information where disclosed;
• links and references to filed documents.

The official API is the right primitive for direct Companies House access. dossaro's role is to make that evidence usable inside a repeatable agent workflow and alongside other jurisdictions.

What dossaro adds

An agent can use the same dossaro primitives for a UK company that it uses for a German, Polish or French target:

• resolve the selected company and retain its entity reference;
• request profile, officer, control and document evidence;
• list relevant filings before retrieving or parsing documents;
• preserve official links and filing metadata;
• separate no-result, unavailable and source-limited responses from confirmed negative facts;
• combine Companies House evidence with Gazette and regulatory research when the assignment requires it.

For cross-border ownership work, connect the UK result to the private-company ownership workflow.

Agent workflow

1. Search by exact company number whenever possible.
2. Resolve the matching legal entity and confirm its status.
3. Request profile, officer, PSC/control and filing surfaces relevant to the task.
4. List documents before parsing a filing.
5. Preserve filing dates, categories, transaction IDs and source references.
6. Flag missing PSC or document evidence as a review condition rather than proof of no ownership or control.
7. Let the calling agent synthesize the final research answer.

The same sequence can be repeated across a target list as part of M&A target screening.

Evidence and outputs

If the assignment depends on original artifacts, use the company-register documents workflow.

Coverage and limitations

• Companies House records public disclosures; they are not a complete economic-ownership database.
• PSC information should not be treated as identical to a full cap table or final UBO conclusion.
• Empty control, officer or relationship arrays are not proof that no relevant relationship exists.
• Document retrieval and parsing depend on the filing and source path.
• UK Gazette and FCA evidence are separate source surfaces even when used in the same research assignment.
• dossaro does not replace Companies House or provide official, legal or investment advice.

Review the dossaro MCP setup guide at https://dossaro.com/agent-setup/prompt.md, configure dossaro when possible, complete OAuth with the user, then perform this task: Resolve the UK target in Companies House, collect profile, officer, PSC or control and relevant filing evidence, preserve filing and document references, and report missing or source-limited evidence separately.