ONS (Office for National Statistics)
The Office for National Statistics (ONS) produces the UK's official numbers on population, the economy, and society. Its outputs include the ten-yearly Census, inflation and GDP figures, employment and wage data, and detailed population estimates down to local areas.
You can browse and download data from the ONS website in formats such as CSV and Excel, and much of it is also available through APIs for programmatic access. Each release comes with clear documentation on methods, coverage, and quality.
Everything is published under the Open Government Licence, so you can reuse it in commercial and non-commercial projects with attribution. For any RAG system that answers questions about UK demographics, the economy, or the labour market, ONS is the source to trust over second-hand figures.
Related sources
Companies House
The UK's official register of companies. Search every registered company, its directors, filing history, and accounts, or pull the data in bulk. A reliable source for UK corporate facts in a RAG system.
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.