We are responsible for Census 2021 in England and Wales and for disseminating census statistics for the UK. National Records of Scotland (NRS) is responsible for Census 2022 in Scotland and Northern Ireland Statistics and Research Agency (NISRA) are responsible for Census 2021 in Northern Ireland.

Following the census on 27 March 2011, we published statistics for the whole of the UK on our UK censuses data webpage. We also produced a report showing comparability of the census questions and outputs across the UK (PDF, 930KB).

The Conduct of the 2021 and 2022 Censuses in the UK statement, published 28 January 2021, is the most recent statement of agreement between the National Statistician and the Registrars General for Scotland and Northern Ireland. It aims to increase harmonisation across the UK Censuses in 2021 and 2022.

The ONS, NISRA and NRS are working closely to develop UK wide census results where possible. Our aim is to produce and publish high quality population and housing statistics for each constituent country and whole of the UK.

UK Harmonisation

Why should we harmonise?

Only the census provides consistent statistics for both small areas and small population groups across England and Wales. When combined with data from similar censuses taken in Scotland and Northern Ireland it provides a picture for the United Kingdom.

UK census statistics informs all areas of public life and underpins social and economic policy. The data provides a wealth of information at small geographies to inform local planning and decision-making.

This is recognised in the statement of agreement between the National Statistician and Registrar Generals in The conduct of the 2021 and 2022 Censuses in the UK.

In collaboration with NRS and NISRA, we have published updates, against the original statement of agreement, outlining the progress made by the three census offices towards aspects of harmonisation:

Compliance with the Code of Practice for Statistics, in particular, the trustworthiness and the quality pillars which encourages collaboration and harmonisation as well as following best practice.

Also, users indicated through the Census 2021 Outputs and Dissemination consultation held in 2018 all census outputs should be UK- harmonised where possible, in particular data definitions and outputs released.

What are we doing to harmonise?

The censuses in all the UK countries have been designed to be undertaken in a consistent manner. The three census offices are working closely with each other through multiple topic-based harmonisation working groups that aim to harmonise where possible and maximise the ability to produce UK-wide census information.

There will be some necessary differences in some of the questions, how data are processed, and some methodologies used. Information on these differences and the impacts that they have on comparability of data will be made available through the individual countries' websites.

Work is ongoing to share the lessons learned and best practice from each census office and to identify and explain any areas where UK harmonisation is not possible.

We aim to harmonise and assess the following components, where possible:

  • questions
  • definitions of concepts
  • classifications
  • output category content and labels
  • output geographies

We will produce documentation that will outline the approach taken to ensure harmonisation of questions and outputs. This documentation will also show where outputs have been harmonised.

UK data user engagement

We are committed to developing and delivering UK census outputs that meet users’ needs and deliver the maximum benefits of the censuses. In order to keep the needs of users at the heart of developments, we have set up a User Working Group for UK Census 2021 and 2022 Data.

We are intending membership to have as wide coverage as possible to best understand the range of data required and how it is used.

Membership currently includes the UK census offices, academics, researchers, representatives from local authorities and county councils, central government, charities, and commercial organisations. We welcome any further interest in the group from users of UK data. To apply for membership, please contact census.outputs@ons.gov.uk.

In March and April 2021, a survey was sent to the user members of the User Working Group for UK Census 2021 and 2022 Data. This helped steer the direction and priorities of the newly formed working group and to ensure the group is representative of users of UK census data. The survey asked:

  • details about their role
  • what UK Census data they use and what it is used for
  • their geographical and topic needs
  • any other priorities and concerns they had about UK census data

Our analysis of the responses has been shared with the working group members. We will use the survey responses to help prioritise our work.

As well as traditional communication between the census offices and the user group, we are also piloting a discussion forum for the group to facilitate the sharing of information and ideas of users within the working group.

Are you a UK data user?

We are keen to hear from anyone who uses or plans to use UK Census data, so we can understand and support your needs. Please contact census.outputs@ons.gov.uk.

More information about UK data

Read more about the 2011 UK Censuses and about UK data from UK Data Service census support.

Visit Scotland's UK data page and Northern Ireland's UK data page.

Our Census news page provides the latest updates on progress towards Census 2021. You can find out more about the design of the census, what we have done to develop the questions for 2021 and any upcoming events for Census 2021.