Requirements and recommendations

Due to the significance of some of our findings, confirmation of the continued accreditation of these statistics is conditional on ONS meeting Requirements 1, 2, 3 and 4 before or at the same time as its next planned publication of the MYEs in summer 2026. We expect a public update from ONS detailing how it has met these requirements by this point.

We will review and monitor ONS’s progress against our recommendations and expect ONS to report publicly to us on its progress in relation to these by the end of 2026. To add an additional layer of assurance, we recommend that the Population Statistics System Committee of the UK Statistics Authority play a role in overseeing ONS’s progress in response to the recommendations and report relevant updates publicly through its minutes every six months.

Requirements

Requirement 1: To support user confidence in its decision to continue with the MYEs, ONS must be open and explicit about the strengths and limitations of the current methods and what action ONS is taking, with time scales, to address methodological limitations with independent assurance.

Requirement 2: To ensure that users have confidence in the population baseline underpinning the MYEs, ONS must:

• Clearly set out the pandemic’s impacts on the MYEs, prominently linking to its published COVID-19 impacts report, and publish evidence to justify its claim that its estimates since 2021 are unaffected by systemic pandemic effects, particularly in light of acknowledged uncertainties for some areas.
• Actively engage with users through its established groups to test the adequacy of current guidance and make necessary improvements, ensuring users are explicitly informed about which data and geographies remain vulnerable to pandemic-related distortions.

Requirement 3: To help users better understand the strengths and limitations of the MYEs, ONS must:

• Improve the prominence and clarity of how it communicates uncertainty in its population estimates, particularly for local authority areas with high levels of migration and/or large student populations. This should include enhancing communication for non‑technical users so that they can understand what the estimates should and should not be used for.
• Improve the accessibility, structure, and navigation of key methodological and quality and methodology information (QMI) documentation to support a broader range of users.

Requirement 4: To avoid the risk of users picking up the wrong number for the purpose that they need, ONS must update and promote its guidance for users on which population estimates should be used for which purposes, setting out the strengths and limitations of each.

Recommendations

Recommendation 1: To support user confidence in its plans to improve population statistics, ONS should:

• Develop and publish, as planned, revised goals and criteria to direct and measure the continuous improvement activities in a structured and accountable way. This should include how the work may or may not intersect with plans for the 2031 census.
• Ensure that methodological research and lessons learnt from the development of the ABPEs are incorporated into the plans for the MYEs.
• Report continuous improvement activity for the MYEs to the Population Statistics System Committee (updates to the Committee should include progress made against the OSR recommendations every six months).

Recommendation 2: To support user understanding and confidence in the estimates, ONS should improve its transparency on methods used to measure internal migration. ONS should also provide greater clarity on the assurance and effectiveness of the Higher Education Leavers Methodology (HELM) and evaluate its impact as part of its plans to improve the measurement of internal migration.

Recommendation 3: Given the time passed since 2021, and wider population trends and changes, ONS should conduct and publish deep-dive analyses into areas where users flagged discrepancies to understand how the estimates may have changed since 2021, triangulating its research with other data sources.

Recommendation 4: To help with understanding the differences between MYEs for school-age children and the Department for Education’s (DfE) English school census, ONS should:

• Continue reconciliation work with DfE, accompanied by joint statements that summarise findings and provide explanations where differences persist.
• Engage with Welsh Government to determine if there are any discrepancies between the Wales school census results and MYEs for school-age children in Wales.

Recommendation 5: To enhance the rigour of its quality assurance process and increase user confidence in the accuracy of estimates in some local authority areas, ONS should:

• Revisit its quality assurance process now that a decision has been made around the future of population statistics and identify ways to improve learning lessons across both ABPEs and MYEs following the closure of ONS’s Future of Population and Migration Statistics (FPMS) programme.
• Evaluate and consider the added value that local authorities (LAs) can bring by formally incorporating LA intelligence into the quality assurance process.
• Strengthen its documentation to clearly and transparently explain how intelligence from LAs is considered and assessed, and where it cannot be incorporated, set out the rationale for those decisions.

Recommendation 6: In light of ONS’s plans to revise its estimates for mid-2022 to mid-2024, reflecting improvements already made to long-term international migration (LTIM) statistics, ONS should, when publishing the mid-2025 estimates in summer 2026, undertake a revisions analysis to assess whether the updated figures align more closely with expectations held by some local authorities.

Recommendation 7: To help mitigate user concerns about revisions and publication delays, ONS should update its publication schedule and in future promptly explain to users any unexpected/expected revisions and changes to publication dates in line with its revisions policy.