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 are actually three separate censuses in the United Kingdom – in England and Wales, Scotland, and Northern Ireland – although they are often co-ordinated.
There have only been three occasions in Great Britain where the census has not been decennial: There was no census in 1941 due to the Second World War; a mini-census using a ten per cent sample of the population was conducted on 24 April 1966; and the planned Scottish 2021 census was delayed to 2022 due to the impact of the COVID-19 pandemic.
[1] No census was held in Ireland in 1921, as a consequence of the Irish War of Independence; instead, Northern Ireland carried out a census in 1926, the first there for fifteen years.
[4] The census records which have been published relate to the occupants of each household, as enumerated for the dates given below: Under the 100-year closure rule established after the 1911 census was taken, only summary results for censuses after 1939 – though with significant statistical detail – are published in the months[b] following the enumeration dates given below; the full information (individual household entries) in later censuses will not be released until the dates stated, a century after each later census was conducted.