Recommendation on the future of population and migration statistics: equality impact assessment

The breadth and depth of administrative data held across Government represents a huge opportunity for the transformation of statistics. Extensive work undertaken by the Office for National Statistics (ONS) over the last decade has demonstrated what is possible with these data. This progress demonstrates great promise in the development of official statistics using administrative data.

Following a review of the evidence from the ONS’s research and engagement, including a consultation in 2023, the UK Statistics Authority published its recommendation to government on 17 June 2025, fulfilling its commitment in the 2018 white paper, Help Shape Our Future (PDF, 967KB).

On the advice of the National Statistician, and following a review of all evidence, the Authority has recommended a statistical system for population and migration that combines the strengths of data collection through a questionnaire-based census of the whole population, with the increased value from administrative data, both to support the delivery of a census in 2031 and to deliver improved outputs each year. The Authority has recommended the following three actions to deliver this vision:

1. That the UK Government commission and resource the ONS to conduct a mandatory questionnaire-based census of the whole population for England and Wales in 2031. This should support coherent UK outputs and maximise the benefits from the ONS’s work with administrative data to date, enabling further delivery of such benefits in the future.

2. That the UK Government commission and resource the ONS to develop statistical outputs using administrative data, which provide more frequent estimates and are inclusive in representing society. This should include an administrative-based census of the population.

3. That the UK and Welsh Governments provide a commitment to the regular, reliable and ongoing flow of the critical administrative datasets required, ensuring that data owners deliver on that commitment, and invest in the required improvements to those sources and address the known points of friction that prevent data transfer.

These recommendations would allow the ONS to maintain the pace and ambition of its work to embed administrative data in its population and migration statistics, while responding to user feedback for a comprehensive and inclusive data collection. The Authority’s recommendation notes that the power to call a census for England and Wales rests with government ministers.

The ONS is committed to ensuring that the principles of equality and diversity are at the heart of all its decision making. To help achieve this objective, the ONS undertook this equality impact assessment relating to its proposals for transforming how it produces population and migration statistics.

This document aligns with the requirements laid out by the Public Sector Equality Duty (the equality duty, PSED) as set out in Section 149 of the Equality Act 2010. This requires public sector bodies to have due regard to the need to:

• eliminate unlawful discrimination, harassment and victimisation, and other conduct prohibited by the Act
• advance equality of opportunity between people who share a protected characteristic and those who do not
• foster good relations between people who share a protected characteristic and those who do not

The protected characteristics are:

• age
• disability
• gender reassignment
• pregnancy and maternity
• race
• religion or belief
• sex
• sexual orientation
• marriage or civil partnership

The ONS published an initial interim equality impact assessment, alongside the consultation in 2023, to inform respondents of the perceived impacts that the proposals set out in the consultation may have in relation to the PSED. Published alongside the Authority’s recommendation, this assessment reflects its proposal that a questionnaire-based census should be held in 2031 alongside the ONS’s ongoing work to develop statistical outputs using administrative data.

In June 2023, the Office for National Statistics (ONS) launched a Consultation on the future of population and migration statistics in England and Wales. This consultation provided users of ONS statistics with the opportunity to inform plans for the future of population statistics, including in relation to protected characteristics. The consultation closed in October 2023 and received 706 responses from a range of users covering central and local government, including the health sector, charities, businesses, academics and individuals. Feedback was also collected through engagement events with stakeholders during the consultation period. A report on the consultation’s findings was published alongside the Authority’s recommendation.

Respondents showed widespread support for the continued development of a system that increasingly uses administrative data, delivering the benefits of more timely and frequent data. Alongside this, there was a strong appetite for further assurances on some of the technical details of an administrative system and its delivery. Users required a greater understanding of the proposed statistical design, particularly for producing individual-level data. Users also asked for further evidence around the availability and quality of data on protected characteristics under the Equality Act 2010 and associated characteristics. These data are needed to enable the creation of an inclusive statistical system.

The National Statistician’s Inclusive Data Advisory Committee (NSIDAC) was established to provide independent advice on the ongoing implementation of the Inclusive Data Taskforce’s recommendations for improving the inclusivity of data across the UK statistical system. It reviewed the proposals on the future of population and migration statistics and their implications for data inclusivity. It also provided advice to the National Statistician in 2023, which was published alongside the Authority’s recommendation.

Before making its recommendation to government, the Authority reviewed the evidence from the consultation and our ongoing engagement, including through the UK Statistics Assembly 2025. Please see the Independent report on the 2025 UK Statistics Assembly for more information.

The equality impact assessment published with our 2023 consultation on the future of population and migration statistics compared the statistics currently offered under the existing statistical system against what is expected to become available under the proposed new system based on administrative data, as well as plans for further development.

The Authority’s recommendation that the government commission a questionnaire-based census in 2031 (in addition to continuing to support the development of statistical outputs using administrative data) enables us to combine the strengths of both sources of data.

This combination helps to deliver the benefits outlined in the proposals summarised in our 2023 equality impact assessment, while also addressing the concerns raised by stakeholders through the consultation and other engagement (see Section 2: Findings from consultation responses and engagement).

One area of concern raised by stakeholders was the potential loss of granularity in terms of geographical detail or classification of responses, such as in the number of ethnic groups for which data are available. Another was that using operational data from administrative sources risked definitions diverging from those in the Equality Act 2010, for example the self-reported health information used to monitor disability.

Holding a questionnaire-based census in 2031 would mean that users can expect to see granular data in terms of geography and classifications. As well as providing granular data, a 2031 census would be an important step towards delivering the Authority’s long-term vision. It can help deliver an increasingly admin-based system of population and migration statistics for the future, underpinned by the benchmarking provided through a census data collection.

The combination of the effective use of administrative data and a questionnaire-based census in 2031 would provide users with the granularity they require with an increased understanding of changes to society in the years between censuses.

The power to call a questionnaire-based census for England and Wales rests with government ministers. Following the UK Statistics Authority’s recommendation to hold a census in 2031, the Office for National Statistics will begin planning for the statistical and operational design of an England and Wales census. This includes how a census would be complemented by the longer-term development of statistics based on administrative data.

If ministers agree with the recommendation to hold a census, an equality impact assessment of these plans will be published, as it was for Census 2021.