Billericay to Leeds Train

Greater Anglia, which is operated by the Transport UK Group, provides passenger rail services in the East of England. It operates services on the Great Eastern Main Line from London Liverpool Street to destinations such as Norwich, Ipswich, and Colchester, as well as on the West Anglia Main Line from London Liverpool Street to Cambridge and Stansted Airport. Greater Anglia also operates regional services in Norfolk, Suffolk, Essex, and Cambridgeshire. The Department for Transport has awarded the operating contract for services until 2025 to Abellio East Anglia Limited.

London North Eastern Railway (LNER) is a train operating company in the United Kingdom that operates intercity services on the "East Coast Main Line" between London, Yorkshire, the North East and Scotland. It was formed in 2018 as a result of the UK government's decision to terminate the franchise of Virgin Trains East Coast. LNER is owned by the Department for Transport and managed by the operator of the East Coast Partnership, a joint venture between infrastructure company Network Rail and train operator FirstGroup. LNER operates a fleet of electric and diesel trains, including the Azuma, which is the fastest train in the UK.

London Overground is a suburban rail network in London, England. It was created in 2007 by the merger of the former Silverlink Metro service with other rail services. The network consists of 112 stations and serves 23 London boroughs. London Overground operates on these routes, which include Highbury & Islington to West Croydon/Clapham Junction/Crystal Palace, Richmond/Clapham Junction to Stratford, Gospel Oak to Barking Riverside, Watford Junction to Euston, Liverpool Street to Enfield Town/Cheshunt, Liverpool Street to Chingford, and Romford to Upminster. Overground is operated by Arriva Rail London under a concession from Transport for London.

Northern is a train operating company that provides passenger services across the north of England. Northern is owned by Northern Trains Ltd, a division of "DOHL," the public sector holding company for the Department of Transportation. It is owned by Arriva UK Trains and operates over 2,500 services every weekday, serving cities such as Manchester, Liverpool, Leeds, and Newcastle.

National Rail is a network of railway companies that operate in England, Scotland, and Wales. It encompasses a network of train operators, including Train Operating Companies, open access operators, freight operating companies, and Network Rail. National Rail is managed and supported by the Rail Delivery Group (RDG), which provides essential business services to ensure the smooth operation and coordination of the railway industry.