The UK population reached 69,483,900 at mid-2025, according to an estimate released by the Office for National Statistics on 1 October. That was an increase of 227,700, or 0.33%, from mid-2024. The ONS said this was the slowest rate of increase since mid-2020. The estimate refers to the usually resident population on 30 June 2025; it is not a count of everyone physically present in the country on a particular day.

Growth in the UK total was concentrated overwhelmingly in England. Its population rose to 58,834,800, an annual increase of 227,600 or 0.39%. Scotland reached 5,545,500, up 2,200, while Northern Ireland reached 1,928,400, up 600. Wales fell to 3,175,200, a decrease of 2,800 or 0.09%. The ONS cautioned that the size and direction of the small changes in Scotland and Wales could be revised as more complete data become available.

Net international migration was the largest demographic component of annual growth. The ONS estimated that 886,200 people arrived to live in the UK for at least 12 months and 663,400 left for at least that long, giving net international migration of 222,900. The comparable estimates for the previous year were 1,296,500 arrivals, 644,800 departures and net migration of 651,700. Net migration therefore fell sharply but still added to the population. It is not interchangeable with the change in the population total: that total also reflects births, deaths, movement within the UK and smaller components.

Natural change, the difference between births and deaths, added only 4,900 people to the overall population. There were an estimated 652,400 births, 9,700 fewer than in the previous year and the lowest number for at least 43 years. Deaths were estimated at 647,500, up 1,600. These figures do not cover exactly the same period as calendar-year birth and death statistics: the population estimates track the 12 months ending on 30 June. Rounding and other small components also mean the published component figures need not add precisely to the headline change.

The bulletin also revised earlier population estimates. The UK population at mid-2024 was revised to 69,256,300, 25,200 or 0.04% below the previously published estimate. Estimates for mid-2022 to mid-2024 were updated with improved international migration data for England and Wales, and estimates for mid-2023 and mid-2024 were revised for Scotland. The new mid-2025 estimate is around 3,000 below the provisional UK figure of 69,487,000 published in November 2025. This scheduled revision does not mean the earlier release contained an error: the series is recalculated as migration methods and data sources improve.

The ONS and the national statistical agencies use the cohort component method, which rolls a population base forward using births, deaths and migration. The England and Wales base comes from the 2021 Census; Scotland’s base comes from its 2022 Census. The UK total combines estimates from the ONS, National Records of Scotland and the Northern Ireland Statistics and Research Agency. Their approaches are broadly comparable, but not every country uses identical administrative records or detail. International migration counts movements that change usual residence for 12 months or more; short-term visitors are outside that definition.

The 69.5 million figure is therefore an official estimate for service planning, resource allocation and rate calculations, rather than an immutable headcount. The ONS says uncertainty can accumulate as estimates are rolled forward from the census base and components are measured. It is greater for smaller areas and narrow age-sex groups, so the very small annual movements in Wales and Scotland warrant particular caution. Users are also advised not to splice figures from different release vintages into one time series; they should use the internally consistent series supplied with this edition. Further data and methodological changes may alter estimates in future releases.