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.

British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most rail transport in Great Britain from 1948 to 1997. Originally a trading brand of the Railway Executive of the British Transport Commission, it became an independent statutory corporation in January 1963, when it was formally renamed the British Railways Board.