The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK or U.K.) or Britain, is a sovereign country located off the northwestern coast of the European mainland. It includes the island of Great Britain, the northeastern part of the island of Ireland, and many smaller islands. The United Kingdom consists of four constituent countries: England, Scotland, Wales and Northern Ireland.
The United Kingdom has a highly developed social market economy. In 2026, the United Kingdom is the fifth-largest national economy in the world measured by nominal gross domestic product (GDP), tenth-largest by purchasing power parity (PPP), and about 21st by nominal GDP per capita, constituting 3.38% of world GDP and 2.13% by purchasing power parity (PPP).
The United Kingdom has one of the most globalised economies and comprises England, Scotland, Wales and Northern Ireland. In 2022, the United Kingdom was the fifth-largest exporter of goods and services in the world and the fourth-largest importer. It also had the fourth-largest outward foreign direct investment, and the fifteenth-largest inward foreign direct investment. In 2022, the United Kingdom's trade with the European Union accounted for 42% of the country's exports and 48% of its total imports. The United Kingdom has a highly efficient and strong social security system, which comprises roughly 24.5% of GDP.
The service sector dominates, contributing 82% of GDP; the financial services industry is particularly important, and London is the second-largest financial centre in the world. Edinburgh was ranked 17th in the world, and 6th in Europe for its financial services industry in 2021. The United Kingdom's technology sector has an enterprise value of US$1.2 trillion, with fintech, health technology, and semiconductors accounting for 48% of the value. The aerospace industry in the United Kingdom is the second-largest national aerospace industry. Its pharmaceutical industry plays an important role in the economy. Of the world's 500 largest companies, 20 are headquartered in the UK, with combined global revenues of US$1.45 trillion. The economy is boosted by North Sea oil and gas production; its proven reserves were estimated at 2.9 billion barrels in 2024, although it has been a net importer of oil since 2005. There are significant regional variations in prosperity, with South East England and North East Scotland being the richest areas per capita. The size of London's economy makes it the biggest city by GDP in Europe. In 2022, the UK spent around 2.8% of GDP on research and development.
In the 18th century, Britain was the first nation to industrialise. During the 19th century, through its expansive colonial empire and technological superiority, Britain had a preeminent role in the global economy, accounting for 9.1% of the world's GDP in 1870. The Second Industrial Revolution was also taking place rapidly in the United States and the German Empire; this presented an increasing economic challenge for the UK, leading into the 20th century. The cost of fighting both the First and Second World Wars further weakened the UK's relative position. During the Great Recession of 2008, the UK economy suffered a significant decline, followed by a period of weak growth and stagnation. Slow growth continued following UK's exit from the EU in 2020, which damaged longer-term growth. The UK economy has also been affected by the 2020 coronavirus pandemic.
Largest companies This list shows the UK companies in the Fortune Global 500 list for 2025 which ranks firms by total revenues. Only the top five firms are included as a sample.
RankImageName2024 revenues (USD $M)StaffNotes 18 Shell $289m 96,000 British multinational oil, gas, and renewable energy company including exploration, production, refining, transport, distribution and marketing, petrochemicals, power generation, trading, biofuels, wind power, energy-kite, and hydrogen power. It was established in 1907, and is headquartered in London, and incorporated in the UK. It was formerly known as Royal Dutch Petroleum Co, and The Shell Transport and Trading Company of the United Kingdom. 33 BP $194m 100,000 British multinational oil, gas, and renewable energy company including exploration and production, refining, distribution and marketing, petrochemicals, power generation and trading, biofuels, wind power and solar technology. It was established in 1909, and is headquartered in London. It was formerly known as Anglo-Persian Oil Company, Anglo-Iranian Oil Company, and BP Amaco plc. 56 HSBC Holdings $145m 211,000 British multinational investment bank and financial services holding company. It was first established in 1865 in British Hong Kong, but is now headquartered in London. Former names include The Hong Kong and Shanghai Bank, and The Hong Kong and Shanghai Banking Corporation. 129 Tesco $89m 229,000 British multinational grocery and general merchandise retailer, petrol retailer, software provider and financial services provider. It was first established in 1919 in Hackney, London, first named Tesco in 1924, and is now headquartered in Welwyn Garden City, Hertfordshire. 179Lloyds Banking Group $73m 61,000 British financial services company offering banking, life assurance, and pensions. Its headquarters are in London and its registered office is in Edinburgh. It was formed through the acquisition of HBOS by Lloyds TSB in 2009. It was formerly TSB Group Public Limited Company from 1985 to 1995, and Lloyds TSB Group plc from 1995 to 2009.
Notable companies This is a list of companies of the United Kingdom as well as those first established in the United Kingdom that are no longer British owned, and also including defunct UK companies. Only companies with articles in Wikipedia are included.
K Kaos Filmsis a film production company. It formerly held film competitions. It was established in 2001. Kainosis a computer software company that provides information technology services and consulting for government departments and agencies, businesses, and organisations. It is headquartered in Belfast, Northern Ireland. It was founded in 1986 as a joint venture between Fujitsu and Queen's University of Belfast. Since then the ownership has changed. In 2022 its revenue was £302 million, with a net income of £35 million. Kays of Scotlandis a manufacturer of curling stones based in Mauchline, Scotland. It was founded in 1851 by William Kay and sons Andrew and Thomas. It is owned by the Wylie family. Keen Cityis a film and television production company. Established in 2008, its headquarters is in London. Keepmoatis a house building company headquartered in Doncaster, South Yorkshire. It was founded in 1931 by George Bramall and Dick Ogden as Bramall & Ogden. After acquiring Frank Haslam Milan in 1983 it was renamed Keepmoat. In 2012 it was merged with social housing provider Apollo. In 2014 it was acquired by TDR Capital and Sun Capital Partners. In 2021 it was acquired by Aermont Capital. In 2020 its revenue was £406 million, with a net income loss of £14 million. Keith and Dufftown Railwaywas a railway company established in 1857 that operated from 1862 to 1866 when it was absorbed into the Great North of Scotland Railway. Kelda Groupis a utility company (water and sewage). Established in 1989, its headquarters is in Bradford, Yorkshire. Its subsidiaries are Yorkshire Water and Kelda Water Services. Keller Groupis a geotechnical engineering company headquartered in London. It was established in the 1950s as the ground engineering division of GKN. In 1975 it acquired the German company Johann Keller and was renamed Keller. In 1990 it was the subject of a management buyout from GKN. Its subsidiaries include: Cyntech, GEO-Instruments, Suncoast Post-Tension, Moretrench Industrial, and Phi Group. In 2022 its revenue was £2.9 billion, with a net income of £45 million. Kelvin Valley Railwaywas a railway company established in 1873. It operated from 1878 with the line worked by the North British Railway who absorbed it in 1885. Kenley Water Companywas a utility company (water supply) until 1885. In 1885 it merged with Caterham Springwater Company to form the East Surrey Water Company. Kent Relianceis the trading name of OneSavings Bank plc. KeolisAmey Walestrading as Transport for Wales Rail Services was a train operating company owned by KeolisAmey that worked the Wales & Borders franchise from 14 October 2018 to 6 February 2021. It ran most of the services in Wales, including all Welsh stations, as well as some services in North West England, West Midlands and Gloucestershire. The Welsh Government body Transport for Wales awarded the Wales & Borders franchise to KeolisAmey in 2018. It was to have run for 15 years but due to the COVID-19 pandemic the franchise became financially unviable and was nationalised by the Welsh Government in February 2021. Operations were transferred from KeolisAmey to Transport for Wales Rail. Amey Keolis Infrastructure continued to be involved in some infrastructure projects such as the South Wales Metro. Kier Groupis a construction, civil engineering, support services, and property management company. It is headquartered in Manchester. It was founded in 1928 by Jorgen Lotz and Olaf Kier as Lotz & Kier, based in Stoke-on-Trent. After Lotz left the company it was renamed J.L. Kier & Co Ltd. It first specialised in concrete engineering before expanding into general contracting and house building. In 1963 it was floated on the London Stock Exchange. In 1973 it was merged with W. & C. French to form French Kier, which was acquired by Beazer in 1986. Hanson bought Beazer in 1991 and then, in 1992, the contracting division known as Kier was the subject of a management buyout. Kier re-entered the housing market with a number of acquisitions and was floated on the London Stock Exchange in 1996. It then expanded its construction, support services, and property management businesses. In 2021 its house building division Kier Living was acquired by Terra Firma Capital Partners and rebranded as Tilia Homes. In 2022 the revenue of Kier Group was £3.2 billion, with a net income of £12 million. Kilchoman distilleryis a producer of Scotch whisky located on Islay, Scotland. It was founded in 2005 by Anthony Wills. Killin Railwaywas a railway company established in 1882 that operated from 1886 with the Caledonian Railway working the line. In 1923 it was absorbed into the London, Midland and Scottish Railway. Kilmarnock and Troon Railwaywas a railway company established in 1808 that began operating in 1812 as a plateway with horse-pulled wagons. From 1841 it operated as a railway which, in 1846, was leased to the Glasgow, Paisley, Kilmarnock and Ayr Railway. In 1899 the line was bought by the Glasgow and South Western Railway. Kimbolton Fireworkswas a manufacturer of display fireworks based in Kimbolton, Cambridgeshire. It was founded in 1964 by Ronald Lancaster. It ceased trading in 2019 but the brand name is used by Phoenix Fireworks, and Celtic Fireworks. Kindle Entertainmentis a television production company. Established in 2007, its headquarters is in London. Kingfisheris a multinational retail company with subsidiaries including B&Q, Castorama, Brico Dépôt and Screwfix. It was established in 1982 as Paternoster Stores in order to buyout the British Woolworths chain after which it became Woolworth Holdings. Its acquisition of Woolworths Ltd included B&Q. Further acquisitions included Superdrug and Comet which were sold in the 2000s. In 1989 it was renamed 'Kingfisher plc'. In 1999 it acquired Screwfix, and other acquisitions include Castorama and Brico Dépôt. Woolworths was demerged in 2001. Headquartered in London, its 2022 revenue was £13.1 billion, with a net income of £843 million.