This is an updated statement of agreement between the National Statistician and the Registrars General for Scotland and Northern Ireland about the next Censuses to be conducted throughout the UK. The previous statement of agreement included the intention to conduct them simultaneously throughout the UK in 2021. A similar agreement was developed for the 2011 Censuses that is believed to have enhanced the extent of harmonisation across the 2011 Censuses throughout the UK.

The unprecedented coronavirus (COVID-19) pandemic has presented a challenge to the UK census offices. As a result of this, in July 2020, the Scottish Government announced that to secure high-quality outputs, Scotland’s Census will now take place in March 2022. However, the Office for National Statistics (ONS) and Northern Ireland Statistics and Research Agency (NISRA) will continue to deliver the Census in March 2021 as planned.

A census is taken by the Office for National Statistics and the Registrar General for Scotland under the Census Act 1920 and by the Registrar General for Northern Ireland under the Census Act (Northern Ireland) 1969. The necessary subordinate legislation, relating to the specific arrangements for the census in each country, requires the approval of the UK Parliament in Westminster (for England and Wales) the Scottish Parliament, and the Northern Ireland Assembly respectively.

Welsh Ministers are consulted on the census for England and Wales, and are responsible for making Census Regulations for Wales.


Each country will be autonomous, with the final decision lying with the National Statistician and the relevant Registrar General, ministers and legislatures.

Subject to that autonomy, the National Statistician and Registrars General agree that the three census offices (the Office for National Statistics (ONS), National Records of Scotland (NRS) and the Northern Ireland Statistics and Research Agency (NISRA)) will aim to work in unison to ensure that the 2021 and 2022 Censuses are a success in providing high-quality population and housing statistics for the constituent countries of the UK, and where possible meeting the needs of UK data users and reflecting UN-ECE and other international requirements.

In particular, the National Statistician and the Registrars General have agreed that the three census offices and the Welsh Government will work together and will reach mutual agreement wherever possible on the points in this statement of agreement, which will facilitate harmonisation where it is in the interest of census users and the public good more generally.

The census offices will consult regularly with users and keep this agreement on harmonisation under constant review.

UK and international requirements

As described earlier on this page, the conduct of the censuses are themselves subject to, variously:

They are also subject to subsequent secondary legislation, including:

The UK is committed to alignment with international standards as there is a user demand for consistent, coherent and accessible statistics for the UK, for each country and geographic areas within each country.

Harmonised aspects

The National Statistician and the Registrars General have, subject to the need for approval where appropriate by the relevant legislatures, agreed the following aspects of the census where they will aim to achieve harmonisation.

Harmonised outputs

The 2021 and 2022 Census outputs should constitute consistent, coherent and accessible statistics for the individual countries and geographic areas within each country and for the UK where possible.

Common definitions and classifications, typically based on international standards, should be agreed, used and published. (This includes a common population base.)

Common topics and questions have been agreed wherever possible, with the intention of making available consistent census outputs across the UK.

Census procedures

The censuses for England and Wales and Northern Ireland should be carried out with reference to the same date in 2021. The census in Scotland is planned for 2022, but will follow harmonised approaches where feasible.

The statistical procedures applied to the census data, such as methodologies for statistical disclosure control and estimation should be evaluated, tested and agreed in advance of the census, and co-ordinated across the UK.

Recognising their common requirements, the census offices will share skills and experiences and endeavour to exploit economies of scale and opportunities arising from the different census day dates wherever possible.

The census offices will work together to exploit, and make greater use of, administrative data sources.

The census offices will endeavour to ensure that the publicity campaigns for each census complement each other.

Governance and dispute resolution

To promote UK harmonisation, every effort will be made to reach agreement through the cross-working mechanisms of the three census offices and any differences of opinion will be discussed and resolved at the UK Census Committee.

You can find out more about the design of the census and what we have done to develop the questions for 2021, as well as the latest news and updates on progress towards census 2021.