Companies House is the UK government agency that is responsible for registering and maintaining records for all UK companies. Companies House is a part of the Department for Business, Energy and Industrial Strategy and is based in Cardiff, Wales.

Companies House maintains a database of information on all UK companies, including their directors, shareholders, and financial accounts. This information is available to the public and can be accessed online through the Companies House website.

Companies House plays a vital role in the UK's business landscape by providing a central repository of information on companies and by ensuring that companies meet their legal obligations to disclose information about their operations. It is an important resource for businesses, investors, and the general public.