The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Western Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, and many smaller islands within the British Isles. Northern Ireland shares a land border with the Republic of Ireland; otherwise, the United Kingdom is surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea. The total area of the United Kingdom is 242,495 square kilometres (93,628 sq mi), with an estimated 2023 population of over 68 million people.
The population of the United Kingdom was estimated at over 67.0 million in 2020. It is the 21st most populated country in the world and has a population density of 270 people per square kilometre, with England having significantly greater density than Wales, Scotland, and Northern Ireland. Almost a third of the population lives in south east England, which is predominantly urban and suburban, with about 9 million in the capital city, London, whose population density is just over 5,200 per square kilometre.
Postal codes used in the United Kingdom, British Overseas Territories and Crown dependencies are known as postcodes. They are alphanumeric and were adopted nationally between 11 October 1959 and 1974, having been devised by the General Post Office. A full postcode is known as a "postcode unit" and designates an area with several addresses or a single major delivery point.
Demographics of Wales include the numbers in population, place of birth, age, ethnicity, religion, and number of marriages in Wales.
The demography of England has since 1801 been measured by the decennial national census, and is marked by centuries of population growth and urbanization. Due to the lack of authoritative contemporary sources, estimates of the population of England for dates prior to the first census in 1801 vary considerably. The population of England at the 2021 census was 56,489,800.
ONS codes are geocodes maintained by the United Kingdom's Office for National Statistics to represent a wide range of geographical areas of the UK, for use in tabulating census and other statistical data. These codes are also known as GSS codes, referring to the Government Statistical Service of which ONS is part.
Religion in the United Kingdom, and in the countries that preceded it, has been dominated for over 1,400 years by various forms of Christianity, replacing Romano-British religions, Celtic and Anglo-Saxon paganism as the primary religion. Religious affiliations of United Kingdom citizens are recorded by regular surveys, the four major ones being the national decennial census, the Labour Force Survey, the British Social Attitudes survey and the European Social Survey.
The CR postcode area, also known as the Croydon postcode area, is a group of eight postcode districts in England, within ten post towns. These cover parts of southern Greater London and north-east Surrey.
Coincident full censuses have taken place in the different jurisdictions of the United Kingdom every ten years since 1801, with the exceptions of 1941, Ireland in 1921/Northern Ireland in 1931, and Scotland in 2021. In addition to providing detailed information about national demographics, the results of the census play an important part in the calculation of resource allocation to regional and local service providers by the UK government.
The demography of London is analysed by the Office for National Statistics and data is produced for each of the Greater London wards, the City of London and the 32 London boroughs, the Inner London and Outer London statistical sub-regions, each of the Parliamentary constituencies in London, and for all of Greater London as a whole. Additionally, data is produced for the Greater London Urban Area. Statistical information is produced about the size and geographical breakdown of the population, the number of people entering and leaving country and the number of people in each demographic subgroup. The total population of London as of 2021 is 8,799,800.
White British is an ethnicity classification used for the native white population identifying as English, Scottish, Welsh, Cornish, Northern Irish, or British in the United Kingdom Census. In the 2011 census, the White British population was 49,997,686, 81.5% of Great Britain's total population. For the United Kingdom entirely, due to different reporting measures within Northern Ireland which includes all those who identified as British with those who identified as Irish, an amalgamated total of 52,320,080 including those who identified as White Irish in Great Britain is given making up 82.8% of the population.
The BT postcode area, also known as the Belfast postcode area, covers all of Northern Ireland and was the last part of the United Kingdom to be coded, between 1970 and 1974. This area is a group of 82 postcode districts in Northern Ireland, within 44 post towns and around 47,227 live postcodes.
The Neighbourhood Statistics Service (NeSS) was established in 2001 by the UK's Office for National Statistics (ONS) and the Neighbourhood Renewal Unit (NRU) - then part of the Office of the Deputy Prime Minister (ODPM), now Communities and Local Government (CLG) - to provide good quality small area data to support the Government's Neighbourhood Renewal agenda. This cross-Government initiative also involved the co-operation and partnership of data suppliers across departments, agencies and other organisations. The ONS closed the Neighbourhood Statistics website for England and Wales on the 12 May 2017. To offset this, the ONS is aiming to meet the needs of users via the ONS website, although direct postcode searches are no longer available to users.
The NE postcode area, also known as the Newcastle upon Tyne postcode area, is a group of 61 postcode districts in north-east England covering 34 post towns. These cover most of Tyne and Wear and Northumberland, plus a very small part of northern County Durham. The NE postcode area is one of six with a population above 1 million.
The TR postcode area, also known as the Truro postcode area, is a group of 27 postcode districts in South West England, within 15 post towns. These cover west Cornwall, including Truro, Penzance, Camborne, Falmouth, Hayle, Helston, Marazion, Newquay, Penryn, Perranporth, Redruth, St Agnes, St Columb and St Ives, plus the Isles of Scilly.
Since 1922, the United Kingdom comprises four constituent countries: England, Scotland, and Wales, as well as Northern Ireland. The UK Prime Minister's website has used the phrase "countries within a country" to describe the United Kingdom. Some statistical summaries, such as those for the twelve NUTS 1 regions of the UK, refer to Northern Ireland, Scotland, and Wales as "regions". With regard to Northern Ireland, Scotland and Wales particularly, the descriptive name one uses "can be controversial, with the choice often revealing one's political preferences".
A census of the population of the United Kingdom is taken every ten years. The 2011 census was held in all countries of the UK on 27 March 2011. It was the first UK census which could be completed online via the Internet. The Office for National Statistics (ONS) is responsible for the census in England and Wales, the General Register Office for Scotland (GROS) is responsible for the census in Scotland, and the Northern Ireland Statistics and Research Agency (NISRA) is responsible for the census in Northern Ireland.
The 2021 United Kingdom census is the 23rd official census of the United Kingdom. Beginning in 1801, they have been recorded every 10 years. The decadal 2021 censuses of England, Wales, and Northern Ireland took place on 21 March 2021, and the census of Scotland took place 365 days later on 20 March 2022. The censuses were administered by the Office for National Statistics (ONS) in England and Wales, by the Northern Ireland Statistics and Research Agency (NISRA) in Northern Ireland, and by the National Records of Scotland in Scotland. These were the first British censuses for which most of the data was gathered online. Two of them went ahead despite the COVID-19 pandemic, in part because the information obtained would assist government and public understanding of the pandemic's impact. The census-taking in Scotland was postponed, and took place in 2022 because of the pandemic.
The ONS Postcode Directory (ONSPD) relates both current and terminated postcodes in the United Kingdom to a range of current statutory administrative, electoral, health and other area geographies. It also links postcodes to pre-2002 health areas, 1991 Census enumeration districts for England and Wales, 2001 Census Output Areas (OA) and Super Output Areas (SOA) for England and Wales, 2001 Census OAs and SOAs for Northern Ireland and 2001 Census OAs and Data Zones (DZ) for Scotland. It helps support the production of area based statistics from postcoded data.
