The United Kingdom has a mixed economy that is the fifth largest in the world in terms of market exchange rates and the sixth largest by purchasing power parity (PPP). It is considered the second largest economy in Europe after Germany's. Its GDP PPP per capita in 2007 is the 22nd highest in the world. The United Kingdom is one of the world's most globalised countries. The capital, London, is a major financial centre of the world, in front of New York City, Hong Kong and Singapore. The British economy is made up (in descending order of size) of the economies of England, Scotland, Wales and Northern Ireland. In 1973, the UK acceded to the European Economic Community which is now known as the European Union after the ratification of the Treaty of Maastricht in 1993.

In the 1980s, under the Government of Margaret Thatcher, most state-owned enterprises in the industrial and service sectors, which since the 1940s had been nationalised, were privatised. The British Government now owns very few industries or businesses - Royal Mail is one example. Following the end of World War II, despite a largely prosperous period in the 1950s and 1960s, the British economy recorded weaker growth than other European nations and by the 1970s was referred to as the "sick man of Europe". However, the 1980s saw a new economic boom and in recent years Britain has seen the longest period of sustained economic growth for more than 150 years, having grown in every quarter since 1992.

It is one of the strongest EU economies in terms of inflation, interest rates and unemployment, all of which remain relatively low. The United Kingdom, according to the International Monetary Fund, in 2007 had the ninth highest level of GDP per capita in the European Union in terms of purchasing power parity, after Luxembourg, Ireland, the Netherlands, Austria, Denmark, Sweden, Belgium and Finland. However, in common with the economies of other English-speaking countries, it has higher levels of income inequality than many European countries. During August 2008 the IMF has warned that the UK economic outlook has worsened due to a twin shock: financial turmoil as well as rising commodity prices. Both developments harm the UK more than most developed countries, as the UK obtains revenue from exporting financial services while recording deficits in finished goods and commodities, including food.

The UK has the world's third largest current account deficit, despite significant oil revenues. This is mainly the result of a large deficit in the trade in manufacture goods. During May 2008, the IMF advised the UK government to broaden the scope of fiscal policy to promote external balance. Although the UK's "labour productivity per person employed" has been progressing well over the last two decades and has overtaken productivity in the united Germany, it lags around 20% behind France's level, where workers have a 35-hour working week. The UK's "labour productivity per hour worked" is currently on a par with the average for the "old" EU (15 countries). The United Kingdom currently ranks 16th on the Human Development Index.

Financial intermediation

London is the world's largest financial centre, with financial services based around two districts: 'The City' (the City of London) and the Docklands (particularly around Canary Wharf). The City houses the London Stock Exchange (shares and bonds), London Metal Exchange (Base Metal and Plastic futures), Lloyds of London (insurance), and the Bank of England. The Docklands began development in the 1980s and is now home to the Financial Services Authority, as well as several important financial institutions (such as Barclays Bank, Citigroup and HSBC). There are now over 500 banks with offices in the City and Docklands, with the majority of business in London being conducted on an international basis, with established leads in areas such as Eurobonds, Foreign exchange markets, energy futures and global insurance. The Alternative Investments Market has acted a growth market over the past decade, allowing London to also expand as an international equity centre for smaller firms.

The United Kingdom had £21bn of financial exports in 2005, contributing significantly towards the Balance of Payments. The UK has had an expanding export business in financial service, which has been influenced by a mixture of unique institutions, light regulation, and a highly skilled workforce.

Edinburgh also has a long established financial industry, the fifth largest financial centre in Europe, with many large firms based there, including the Royal Bank of Scotland (the second largest bank in Europe), HBOS (owners of the Bank of Scotland) and Standard Life Insurance.

Several of the major English cities have large financial sectors & related services, notably the Leeds city region which is home to several large banks & building societies. Manchester also has a large financial sector, including the Co-Operative Financial Services, who run the most successful ethical fund in the UK and are the only major unit managers outside of London & Edinburgh. Manchester also has the largest professional services sector outside the South East, particularly legal activities.