You asked
FOI reference: FOI-2026-3429
I would like to request the Year ending June 2025 edition of the Long-term international immigration, emigration and net migration flows, provisional series with unrounded figures for immigration, emigration and net migration estimates, across all tables, in the same layout/format as they are in the public release, which has rounded figures.
We said
Thank you for your Freedom of Information request.
We confirm that the Office for National Statistics (ONS) holds unrounded estimates which are used internally for the purposes of statistical processing. Due to the work involved in prepping this information for public release, this would need to be produced via our bespoke services route for a charge. These services are subject to disclosure controls, legal frameworks, and an agreement of costs in line with our Charging Policy. To discuss an order for this information further, please contact pop.info@ons.gov.uk.
As the requested information is reasonably accessible via another route, even if only on payment, the exemption found under s.21(2)(a) of the Freedom of Information Act (2000) applies.
However, please note that we advise caution when using this information. As set out in the published tables, provisional migration estimates are rounded to the nearest 1,000 to reflect the quality and inherent uncertainty of the estimates. The unrounded estimates you have requested are not more accurate than the rounded figures. They are intermediate processing outputs used to generate provisional published statistics. The final step in the statistical process is rounding, which is undertaken deliberately and in line with ONS Quality Central guidance. ONS guidance makes clear that rounding is necessary to ensure figures are presented in a way that:
Reflects the level of accuracy supported by the underlying data, and
Avoids implying false precision for estimates that inherently contain uncertainty.
This approach is consistent with the Code of Practice for Statistics, particularly Practices 1.3, 7.1, 7.2, and 7.3, which require producers to publish statistics in ways that are appropriate, transparent and not misleading. Therefore, the data requested is not the data we would recommend to use to understand long-term international immigration further.