United Kingdom

The census in the United Kingdom is decennial, that is, held every ten years, although there is provision in the Census Act 1920 for a census to take place at intervals of five years or more. There have only been two occasions where the census has not been decennial: There was no census in 1941 due to the war; and a mini-census using a ten percent sample of the population was conducted on 24 April 1966. There are actually three separate censuses in the United Kingdom - in England and Wales, Scotland, and Northern Ireland, although they are often coordinated. From 1821 until 1911, the census included the whole of Ireland.

Tax assessments (known in the later Empire as the indiction) were made in Britain in Roman times, but detailed records have not survived. In the 7th century AD, Dál Riata (parts of what is now Scotland and Northern Ireland) conducted a census, called the "Tradition of the Men of Alba" (Senchus fer n-Alban). England conducted its first formal census when the Domesday Book was compiled in 1086 under William I for tax purposes.

Distinct from earlier, less inclusive censuses (e.g. for religious purposes), national decennial censuses of the general population started in 1801, championed by the statistician John Rickman. The censuses were initially conducted partly to ascertain the number of men able to fight in the Napoleonic Wars, and partly over population concerns stemming from the 1798 work An Essay on the Principle of Population by Reverend Thomas Robert Malthus. Rickman's twelve reasons - set out in 1798 and repeated in Parliamentary debates - for conducting a census of Great Britain included the following justifications:

• "the intimate knowledge of any country must form the rational basis of legislation and diplomacy"

• "an industrious population is the basic power and resource of any nation, and therefore its size needs to be known"

• "the number of men who were required for conscription to the militia in different areas should reflect the area's population"

• "there were defence reasons for wanting to know the number of seamen"

• "the need to plan the production of corn and thus to know the number of people who had to be fed"

• "a census would indicate the Government's intention to promote the public good"

• "the life insurance industry would be stimulated by the results".

Regular national censuses have taken place nearly every ten years since 1801, most recently in 2011; other partial censuses have been made on some of the intervening fifth anniversaries. The first four censuses (1801-1831) were mainly statistical: that is, mainly headcounts, with virtually no personal information. A small number of older records exist in local record offices as by-products of the notes made by enumerators in the production of those earlier censuses; these might list all persons or just the heads of households. The 1841 Census was the first to intentionally record names of all individuals in a household or institution.

The Census Act of 1920 provides the legal framework for conducting all censuses in Great Britain (Scotland, England, and Wales). The primary legislation for Northern Ireland was introduced in 1969. Before this legislation, it was necessary to have a separate act of parliament for each census. Britain was also responsible for initiating and co-ordinating censuses in many of its overseas colonies.

Because of the disruption caused by the Second World War, there was no census in 1941. However, following the passage into law on 5 September 1939 of the National Registration Act 1939, a population count was carried out on 29 September 1939. The resulting National Register was later used to develop the NHS Central Register. Censuses were taken on 26 April 1931 in Great Britain, but the returns for England and Wales were destroyed in an accidental fire during the Second World War.

On 24 April 1966, the UK trialled an alternative method of enumeration - long form/short form. Every household was given a short form to complete, while a sample of the population was given a long form to collect more detailed information. The short form was used for the population count and to collect basic information such as usual address, sex, age and relationships to other household members. This was the first and only time that a five-yearly census was carried out in the UK.

Census in the United Kingdom - Wikipedia