The importance of population and migration statistics 

Population and migration statistics support decisions and policies right across our society and economy at national and local levels and for different communities. For example, they are crucial in determining: 

  • the amount of housing we need 

  • the numbers of education places 

  • other infrastructure requirements  

The statistics we produce at the Office for National Statistics (ONS) are a trusted source of official population and migration data. They are used by government departments, local authorities, businesses, charities and many more to inform decisions that affect everyone.  

Why we are transforming population and migration statistics 

For over 200 years, the census has been the main way of collecting data for population statistics, and they provide an accurate picture of our society at a national and local level. However, it only happens every 10 years. Census data are updated each year with survey and administrative data. However, these statistics become less accurate over the decade and local detail on important topics is not available between census years.  

Policy users and decision makers have often told us they would benefit from more frequent and timely statistics. Greater use of administrative data will help us meet these needs. 

Using a range of sources from across government and the public sector, we can produce more timely and frequent local area statistics about the size and structure of the population and its characteristics. For more information on the dynamics of population change, please see our Dynamic population model for England and Wales: July 2022 article.  

The proposed transformed statistical system is responsive to changing user needs and will provide users with more frequent population statistics with consistently high quality every year.  

Watch our animated video to find out more about why we are transforming the way we produce statistics.  

Administrative data 

Administrative data are data that we have primarily collected for administrative or operational purposes. They are made up of information that we all provide when we access public services like the tax, benefits, health and education systems. For example, we use the numbers of registered births and deaths along with health and census data to create statistics on health inequalities in different social classes, based on a person's occupation. 

Linked data 

"Linked data" means linking to other data sources. We do this to identify new patterns and insight.  

We used linked data, such as public transport data, combined with information from our own Coronavirus (COVID-19) Infection Survey, to help us understand infection rates in different groups during the coronavirus pandemic.

How we protect the confidentiality of data 

The ONS has a proven track record of protecting sensitive data. This has been built over many decades of delivering the census in England and Wales and the UK’s biggest regular household surveys. For more information, see our Data strategy webpage.

The ONS follows data protection legislation. This means that when we consider new uses of personal data, we can ensure the use is necessary, proportionate and transparent before proceeding. When we identify potential risks, we also produce Data Protection Impact Assessments. These are necessary to understand and mitigate data protection risks. 

We protect administrative data to the same high standards as census data. It is a legal duty to maintain confidentiality under the Statistics and Registration Service Act 2007 and the Data Protection Act 2018. Strong sanctions are in place to stop anyone from disclosing or seeking to disclose personal data. 

Access to person identifiers, such as name and detailed address, are restricted to a small number of ONS employees. Once data are linked, person identifiers are removed from the data used for wider statistical analysis. 

All of our procedures, systems and staff protect both the data and your confidentiality by law, so no one can be identified from the statistics we publish. 

The rest of the UK 

The ONS has responsibility for the census and population statistics for England and Wales. Therefore, the consultation and subsequent National Statistician's recommendation will relate to England and Wales. We are working closely in partnership with the Welsh Government.  

The National Records of Scotland (NRS) and the Northern Ireland Statistics and Research Agency (NISRA) are developing their plans in parallel; the ultimate decision on the future approach in Scotland and Northern Ireland is for the respective devolved administrations. 

The National Statistician, Registrars-General and Chief Statisticians signed the Statement of agreement: cooperation on future UK population and social statistics in November 2022, available on the UK Statistics Authority website. This will will support the production of coherent UK statistics, comparable between the countries of the UK. 

The implementation of the agreement is being reviewed annually by the signatories and there is ongoing engagement between all four nations. 

Equality Impact Assessment report

The Office for National Statistics (ONS) is committed to ensuring that the principles of equality and diversity are at the heart of all of its decision making. To help achieve this goal, the ONS has undertaken an equality impact assessment The future of population and migration statistics in England and Wales: equality impact assessment relating to its proposals for transforming population and migration statistics.

Our transformation journey 

The government has an ambition that “censuses after 2021 will be conducted using other sources of data and providing more timely statistical information”. In the Help Shape Our Future: The 2021 Census of Population and Housing in England and Wales White Paper, available on GOV.UK, we committed to delivering recommendations on the future of population and migration statistics in England and Wales.

Since then, we have been conducting extensive research to provide evidence for our recommendations. This research has looked at primarily using administrative sources to produce estimates about the population and its characteristics.  

Our Progress updates page sets out how we are developing this work.

The consultation on the future of population and migration statistics in England and Wales  

As our transformation journey progresses, we will continue to engage with users across government, the public sector, businesses, the third sector and academia. 

As part of this engagement, we conducted a consultation that opened on 29 June 2023 and closed on 26 October 2023.  

In support of the consultation, we held a series of roundtables, webinars and meetings with a diverse range of users from the private and public sectors, as well as charities and community groups. We asked for their views on how our proposals for a new approach to population and migration statistics in England and Wales could meet their needs compared with the current approach.  

The responses we have received will inform a recommendation to government from the UK Statistics Authority, on the advice of the National Statistician. 

More information and the latest news about the consultation is available on the Consultation publications and updates page.