Census

The home for census data for all parts of the UK

Statistics from the UK censuses help paint a picture of the nation and how we live. They provide a detailed snapshot of the population and its characteristics and underpin funding allocation to provide public services.

The UK Data Service holds and enables access to aggregate, boundary, flow and microdata from the last seven censuses from 1961 through to 2021/22. Also through Integrated Census Microdata (I-CeM), we provide access to census data from 1851-1911.

Census 1961 – 2021/22

The UK Data Service provide access to a large number of census datasets. The collection is being expanded as we add data from new censuses, and also as we make available new datasets from older censuses.

The datasets are broadly divided by the type of data: aggregate data (the most commonly used data, the numbers of people with certain characteristics), flow data (a form of aggregate data about people moving between locations), microdata (samples of individual records, with identifying variables removed), and boundary data (allowing maps to be drawn and other forms of spatial analysis to be conducted).

Aggregate data 1971 – 2021/22

Boundary data

Flow data

Microdata

What is census aggregate data?

These data are outputs from the UK Census of Population, they are anonymised, grouped into geographical areas and put into tables of themes or to answer specific questions. They are what most people think of when they are looking for ‘census data’.

An example of this might be ‘the number of people aged 60, resident in Liverpool in 2021’ or ‘males, aged 20-24 living in Scotland who speak Gaelic in 2001.

The UK Data Service holds census aggregate data from 1971 to 2021/22 (England, Wales and Northern Ireland held their census in 2021, Scotland delayed until 2022 due to worries about Covid).

Obtaining census aggregate data

The UK Data Service provides web-based interfaces that enable users to access and extract data from the aggregate statistics outputs from the 1971, 1981, 1991, 2001, 2011, and 2021/22 censuses, together with a range of associated datasets and services.

If you want census data for whole tables of data for large sets of geographies such as ‘all the Westminster Parliamentary Constituencies of England’ or ‘every local government district in Northern Ireland’, especially at very small geographical areas, then we recommend UK Data Service CKAN.

If you want to delve into the data for a specific area, search cross censuses from 1971 to 2022, re-arrange tables and make charts then we can recommend UK Data Service Data Explorer.

You can also access 2001 and 2011 English and Welsh census aggregate data in InFuse. InFuse is designed to guide users in selecting census aggregate data relating to combinations of characteristics and areas of interest to them.

What is census boundary data?

UK aggregate census statistics are output at a range of small area geographies. Census digital boundaries describe the location of these small area output geographies as polygonal GIS datasets.

Linking aggregate census statistics to digital boundaries enables aggregate census statistics to be visualised as maps and enables spatial analysis of census data to be performed.

The UK Data Service holds census boundary data from 1971 to 2021/22.

Obtaining census boundary data

Census boundary data can be accessed from the UK Data Service using our Boundary Data Selector tool.

The Boundary Data Selector tool allows one to identify which census boundary datasets are held by the UK Data Service and to download those boundary datasets in different GIS data formats. The tool provides flexibility such that one can download boundary data for an entire country like England or be more selective and only download boundary data within a region of interest such as a local authority like Leeds or Manchester.

Supporting boundary data datasets: Geographic look up tables

Geographic look up tables relate two or more geographies to one another. An example of a geographic look up tables is the ONS Postcode Directory (ONSPD) which relates postcodes in the UK to a wide range of other area geographies, including UK census geographies. Using the ONSPD would enable you to relate survey data collected by postcodes to census output geographies. The ONS Postcode Directory can be downloaded from the UK Data Service by using the UK Data Service Postcode Data Selector tool.

What is census flow data?

Flow data, also known as origin and destination data and sometimes also called ‘interaction’ or ‘mobility’ data, involve flows of individuals in the UK between origins and destinations. These flows are either the residential migrations of individuals from one place of usual residence to another or of commuters making journeys from home to workplace.

Census flow data are derived from the questions on the census form relating to place of usual residence one year ago, the place of work for the respondent’s main job and, from 2011, if a respondent spends more than 30 days a year at a second address. These flow data are currently available from the UK Data Service at a range of different spatial scales for the 1981, 1991, 2001, 2011, and 2021 censuses.

As flow data feature both a start and end point, this means that tables are often much larger and more complex than for other census data.

Obtaining census flow data

There are open, safeguarded and secure versions of census flow data. To access the safeguarded datasets, you need to be registered with the UK Data Service. For the secure datasets, you also need to be accredited and have your project approved. Access is currently provided through WICID, the Web-based Interface to Census Interaction Data.

What flow data are available?

All census flow data are available through the UK Data Service via the WICID portal. These include data from the 1981, 1991, 2001, 2011, and 2021/22 censuses. The 2021/22 census datasets do not cover the entire UK as Scotland conducted its census a year later. 2021 census flow data are available for England and Wales as well as Northern Ireland and are currently only available as bulk downloads. Census flow data from Scotland are expected to be released by NRS in 2025. A new platform and interface for census flow data are under development, which will replace the WICID portal and introduce subsetting functionality for the 2021/22 data.

What is Census microdata?

Census microdata are anonymised individual data samples from the UK Census of Population. Unlike census aggregate data, which are grouped into geographical areas, microdata provide detailed information on individuals and households, allowing relationships between variables such as age, employment, education, etc. to be explored. These data are particularly useful for multivariate analysis and for studying patterns that do not emerge clearly from aggregate data analysis.

Obtaining Census Microdata

Census microdata are available via the UK Data Service data catalogue and ‘Get census microdata‘ web page.

They include:

  • Teaching files which are designed for introductory analysis and are suitable for users who require less detailed datasets. They are freely accessible and are based on a 1% sample of individuals.
  • Safeguarded microdata which provide greater detail on a 5% sample of individuals and are available to registered users for research purposes. To access safeguarded microdata researchers must be registered with the UK Data Service and agree to the terms of the user licence.
  • Secure microdata are highly detailed individual data based on a 10% sample of individuals. They are made available for in-depth research under strict security protocols and are accessible via the UK Data Service SecureLab. See the ‘What is the UK Data Service SecureLab?‘ web page for more information.

Mapping 2011 census microdata using R guide

One of the advantages of using census microdata is that users can derive bespoke variables unavailable in census tables.

The UK Data Service has produced a guide to show the strength of using census microdata for a variety of research purposes via a worked example taken from real-life research.

View our guide Mapping 2011 Census Microdata using R (PDF).

Census 1851 – 1911

The UK Data Service also provides access to individual level historiccensus records that have been released under the ‘hundred year rule’;these data are supported by the I-CeM project.

Explore

Access

Census explainers

The UK Data Service has written a number of ‘explainer’ documents, which
describe some of the questions asked in the census, how the resulting
data are used to produce outputs, and things that you need to know about
these outputs in order to interpret them effectively.

As well as exploring questions asked in the census – both those which
were newly introduced in the 2021/22 Censuses, and some longer standing
ones – we also look at some of the processes involved in taking the
census and ensuring individual’s data is protected, and key ideas in
understanding the results.

We will publish these explainers in this section over the next few weeks.

Resources

Forms, definitions and websites

Does the census cover the right topics for you?

The census in all UK countries has been undertaken in a consistent manner. However, there are differences in some of the questions asked, processing, and detailed methodology.

Questions and definitions often change between censuses. You can access the census forms including the 2021 Census, census definitions, and the census agencies websites for further information.

Use of census data

Find out what others have done with census data

Below are links to analyses of census data on a variety of topics, including migration and demography, ethnicity and national identity, health, housing, the labour market, language, religion, and unpaid care.

UK Data Service case studies

See case studies related to the census.

Office for National Statistics (ONS) 2011 Census analysis

Detailed analyses of census data on a variety of topics.

Centre on Dynamics of Ethnicity (CoDE)

Briefing documents on the Dynamics of Diversity series evidence from the 2011 Census.

Migration Observatory

The Migration Observatory is making migration-related 2011 Census data available through a suite of outputs.

Mapping census data in QGIS

Mapping census data in QGIS guide

QGIS is an open source mapping package which can be downloaded for free – it has a good range of functionality and is straightforward to use.

It can take census data for a given set of geographic areas (such as local authorities, wards or super output areas) and boundary data for the same set of areas and map the data.

The UK Data Service has produced a guide showing how you can map census data using the QGIS package.

View our guide Mapping Census data in QGIS (PDF).

Other information

Further reading

UK census geography

ONS Census Geography web pages

Geo-Refer (2007) Geographical referencing learning resources

Rees P., Martin D.M. and Williamson P. (2002) The census data system, Chichester: Wiley.

Stillwell, J. (ed.) (2018) The Routledge Handbook of Census Resources, Methods and Applications Unlocking the UK 2011 Census, ISBN 9780367660031, Routledge.

Census2011Geog project

Handling spatial data and GIS

Longley P.A., Goodchild M.F., Maguire D.J. and Rhind D.W. (2001), Geographic information systems and science, Chichester: Wiley.

Martin, D. (1996) Geographic information systems: socioeconomic applications, London: Routledge.

Monmonier, M. (1996) How to lie with maps, Chicago: University of Chicago Press.

Walford, N. (2002) Geographical data: characteristics and sources, Chichester: Wiley.