Census 2021

What is the census?

The UK census is a survey that is carried out every ten years. By surveying every household in England and Wales, the census helps build a detailed snapshot of society.

The Office of National Statistics is responsible for planning and running the census in England and Wales, whilst the National Records of Scotland and Northern Ireland Statistics and Research Agency run their own censuses in their respective geographical areas. Together, the census statistics from each nation create an overall picture of the UK population.

Is the census mandatory?

The Census Act of 1920 made completing the census mandatory in England and Wales.

It is a criminal offence to not fill out the census, and failure to do so, or providing incorrect information can lead to a £1,000 fine and a criminal record.

Whilst you must complete the census, some questions, regarding sexual orientation and religion, are optional.

How often is the census conducted?

The ONS Census is conducted every ten years. Whilst not always on the same date, the census is usually carried out in March or April. Census day for 2021 was Sunday 21st March.

The previous census was conducted on the 27th March 2011, with the census results published the year after.

In the most recent census, it was found that the population had increased and become more diversified in terms of ethnic make-up, the number of Christians and number of homeowners had decreased, whilst the number of cars and vans and number of over 65s had increased since 2001.

Since 1801, there has been a census every ten years, apart from 1941, during the Second World War, when the census was cancelled.

All information is anonymised and the actual census records are kept secure for 100 years.

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What topics are covered in the census?

  • Demography and migration
  • Ethnic group, national identity, language, and religion
  • Health, disability, and unpaid care
  • Housing
  • Labour market and travel to work
  • Sexual orientation and gender identity
  • Education
  • UK armed forces veterans

What is the census data used for?

People and organisations use the census results to aid and guide their work.

  • Local authorities
    • Use census data to develop policies and to plan and run public services, such as schools, health services, roads and libraries.
    • It is also used to decide how to allocate funds to make sure public funds get to where they are needed most.
    • For example, employment data can be used to develop new job and training policies.
    • Population projections in a certain area can help local councils plan educational spending and school investment for the years ahead.
  • Businesses
    • Census information can help companies gain a greater understanding of their customers in their local area.
    • For example, a clothing retailer may use economic activity and boundary data to decide where to open a new store.
  • Voluntary organisations
    • Voluntary organisations often use data to gather more information about their communities and the needs of the people they serve. Data can also be used to support funding applications.
  • Academics and students
    • Census information is used by academics and students in social research to support their work.
  • The public and genealogists
    • Genealogists use census data to research family history. Census research can uncover information on births, marriage, deaths and migration.
    • Specific records are released 100 years after the census took place, so they provide a wealth of information for those researching their family history.

When is census data released?

Census data is published in multiple stages the following year.

For the 2021 census:

  • Phase 1
    • Early Summer 2022
    • The first results will include rounded population and household estimates for England and Wales, at the local authority level and cross-tabulated by sex and age.
    • Then staggered by topic
  • Phase 2
    • Multivariate data for the usual resident population base
  • Phase 3
    • Alternative population bases
    • Small populations
    • Origin-destination data or ‘flow’ data
    • Microdata samples