Background
Population and migration statistics are among the top priority areas set out in the Strategic Business Plan for 2025/2026. Using feedback from our stakeholders to inform our plans and statistics is a crucial part of our approach. Our users need clear communication about our statistics, how they are produced, and our plans given the essential uses for central and local government, academics, media, and other users. To ensure we keep people informed, we are planning how we will engage with users about new methods for population estimates.
In recent years, the move towards a population and migration system based on administrative data has delivered improvements to estimates. The next steps include moving to Admin-Based Population Estimates (ABPEs) for England and Wales as the official estimates of the population. These estimates are central to the evolution of population and migration statistics, and we know that there are a wide range of users we need to engage with.
Aims
The aims of our engagement approach are:
support our users' understanding of admin-based population estimates (ABPEs), the statistical system and reasons for moving to ABPEs as official estimates (England and Wales)
give assurance to our users that ABPEs meet the highest standards of trustworthiness, quality, and value once the ABPE methodology supersedes the current methodology
ensure that user needs have been considered before decisions are made; this includes how revisions will be managed within the new admin-based system
work with users to understand what information they need to support confidence in the new approach
communicate information around plans for releases of ABPEs and other relevant statistics in advance to support users' planning for workstreams which use population estimates
support our users around how best to use interpret and use the information
ensure there are ways for our users to feedback and talk to us about both the statistics and the improvements being made to the population and migration statistical system
increase the transparency of population and migration statistics
assure ourselves that our engagement meets the standard expected in order to achieve accredited official statistic status
Update on engagement undertaken
Approach to revisions
Our proposal for how revisions are managed in the population and migration statistical system was developed by working with users throughout 2024. An early proposal was tested with users and was refined based on feedback. We further developed a new approach and held focus groups with colleagues from across government departments and local authorities. The refined proposal was considered an improvement from the previous version, which included more frequent revisions.
We understood the feedback on revisions and the importance of setting out our publication timetable for population estimates more clearly. We took steps towards this in our publication schedule for admin-based population and migration statistics on 26 February 2025.
Engagement with local authorities
We have met with 10 local authorities invited to work with us to evaluate the quality of the admin-based population estimates (ABPEs) in their areas, based on their local insight and data sources. These local authorities were chosen to ensure we consider different demographic characteristics, for example; student areas, urban and rural areas, and areas with transient populations such as seasonal workers.
Through these conversations we have learnt more about previously identified local challenges to population group estimates which will direct our research, regardless of the methodology used, including;
short-term residents who may not be included in our estimates as usual residents, yet still require services
student populations, particularly those who may not update their information on administrative sources over the course of their studies
estimating both internal and international migration to and from cities, particularly for areas heavily impacted by the coronavirus (COVID-19) pandemic, or those with universities
understanding who is moving into new housing developments and how quickly these moves are picked up in our ABPEs
In response to this feedback, we are developing plans to;
investigate the feasibility of producing an alternative population estimate, which includes short term residents
build on the work on Local authority district case studies of student populations to assess the quality of the data sources used to estimate student populations, and review the use of other sources of data identified through this engagement, for example, university head count data
incorporate this feedback into our research; for example, the inclusion of new data sources in identifying both internal and international migration to and from local authorities
test the timeliness of including residents of new housing developments in our estimates, using case study data supplied by local authorities
In October 2024, we outlined our engagement plan, which included several intentions which we have now made progress with, including:
establishing a new quarterly cross-government meeting to ensure there is a forum to share information about ABPEs and to collaborate across departments
continuing a regular meeting with colleagues in the devolved governments and HM Treasury to assess the effects of moving to ABPEs and the impact on funding for Scotland, Wales, and Northern Ireland
a session with local authorities to understand more about the uses of local authority level international migration flow
meeting with colleagues inside the ONS and government departments who use population estimates before decisions relating to ABPEs are made; this has been an important element of informing our decisions
publishing the criteria which we would use to assure ourselves in moving to ABPEs as the official estimates of the population for England and Wales; an assessment against these criteria has been published.
expanding our programme of webinars to outline trends and support user understanding of our approach
Timeline for engagement
To continue with our engagement and progress towards moving to admin-based population estimates as official estimates, we are setting out our plans for further engagement.
Summer to autumn 2025
Hold further meetings of the newly established Methodological Assurance Review Panel (MARP) Dynamic Population Model sub-group to ensure robust external assurance of methodology used for ABPEs.
Engage with government departments where population estimates are used to confirm any additional support required from the ONS, and assess any impact to ensure confidence in ABPEs before they become the official estimates in 2026.
Publish our response to the engagement exercise in March, used to review the content we publish for population estimates.
Continue to hold webinars on the population and migration statistics system throughout 2025.
Continue to engage with colleagues across UK nations to progress plans for UK population estimates.
Publish further updates to non-technical articles
Continue to review and update supporting information, for example, Understanding mid-year admin-based population estimates, to help users understand our methods and use our estimates with confidence.
Winter 2025 to summer 2026
We intend to publish early indicator population estimates for year ending June 2025.
Ensure users are regularly informed on our progress towards moving to the new methodology in 2026 via regular newsletters, webinars, and quarterly updates. The aim is for ABPEs to become the official estimates of the population for England and Wales in 2026; we will continue to engage with stakeholders once this change is made to ensure we understand ongoing user needs.
We welcome feedback on this approach or the improvements to methodology - pop.info@ons.gov.uk