National Rail (NR) is the trading name licensed for use by the Rail Delivery Group, an unincorporated association whose membership consists of the passenger train operating companies (TOCs) of England, Scotland, and Wales. The TOCs run the passenger services previously provided by the British Railways Board, from 1965 using the brand name British Rail. Northern Ireland, which is bordered by the Republic of Ireland, has a different system. National Rail services share a ticketing structure and inter-availability that generally do not extend to services which were not part of British Rail.

Network Rail Limited is the owner and infrastructure manager of most of the railway network in Great Britain. Network Rail is a non-departmental public body of the Department for Transport with no shareholders, which reinvests its income in the railways.