Companies House
Companies House keeps the statutory record of every company registered in the UK. For each one you can see its registered address, directors, incorporation date, filing history, and published accounts.
You can search the register for free on the website, download bulk data products, or use the API, which returns results as JSON so you can pull company details on demand. Bulk downloads are handy when you want the whole register rather than a single lookup.
The data is published under the Open Government Licence, so you are free to reuse it with attribution. It is well suited to RAG systems that answer questions about UK businesses, verify company details, or trace ownership and directorship links.
Related sources
data.europa.eu
The European Data Portal, a single point of access to open data from 36 European countries and the EU institutions. Over 1.6 million datasets span every policy area, giving RAG systems broad, multilingual coverage of official European data.
data.gov
The US federal government's open data portal, gathering more than 300,000 datasets from federal agencies. Coverage spans agriculture, climate, education, energy, finance, health, and public safety, making it a broad source of official US data for RAG systems.
data.gov.uk
The UK Government's central catalogue of open public sector data, run by the Government Digital Service. More than 47,000 datasets cover health, housing, transport, demographics, and the environment, giving RAG systems a trusted base of UK facts, figures, and official records.
Hansard
The official word-for-word record of proceedings in the UK Parliament, both the Commons and the Lords. Full text searchable and available as XML and linked data going back centuries, it is a rich source of political and legislative debate for RAG systems.