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National population projections: 2021-based interim

On 30 January, the Office for National Statistics (ONS) published 2021-based interim national population projections. The projections are based on the latest provisional estimates of international migration. New assumptions were developed following the latest expert advice and latest provisional estimates of international migration. 

We have also published our own headline on National population projections for Wales.

Main points

  • Between mid-2021 and mid-2031, the population of Wales is projected to increase by 5.8% from 3.11 million to 3.29 million. 
  • The projected growth in the population between mid-2021 and mid-2031 is driven by migration with total net migration of 250,000 between mid-2021 and mid-2031.
  • The projected population increase for Wales between 2021 and 2031 is lower than for England, which is projected to increase the most, by 7.9%.
  • However, the projected population increase for Wales between 2021 and 2031 is higher than Northern Ireland, which is projected to increase by 3.6%.

No 2021-based projections have been published for Scotland because reconciliation and rebasing of population statistics, including international migration statistics for 2012 to 2022 incorporating insights from Scotland's Census 2022, are yet to be finalised. 

StatsWales tables for 2021-based population projections have also been published.

The ONS plans to publish fully updated 2022-based national population projections in October to November 2024. These will be 2022-based, including data from Census 2021 for Wales, England and Northern Ireland, and Census 2022 for Scotland.

We plan to publish our next set of subnational population and household projections once the 2022-based national population projections are published by the ONS. This is currently planned for the first half of 2025. 

If you have any questions, please contact us on

Admin-based population estimates

On 18 December 2023, the ONS published admin-based population estimates (ABPEs) for local authorities in England and Wales. This included updated estimates for mid-2021 and mid-2022, and provisional estimates for mid-2023. Within the article, there is a section comparing these estimates with the official mid-year estimates, which shows the population differences when using different methods.

Please note, the ABPEs do not replace the official mid-year population estimates and international migration statistics that were released on 23 November 2023 and should not be used for decision or policy making.

These official statistics in development are part of ONS’ population and migration statistics transformation programme. This work is ongoing and will be informed by the feedback they have received in the recent consultation on the future of population and migration statistics.

Consultation update on the future of population and migration statistics in Wales and England

On 14 December 2023, the ONS provided a consultation update regarding the future of population and migration statistics in Wales and England. The update details the number of consultation responses by sector and outlines how the ONS engaged with users of population and migration statistics both before and during the consultation. It also explains how the ONS is carrying out its analysis of the responses.

An analysis of the consultation responses will be published alongside the recommendation in 2024. 

Census 2021 StatsWales tables

On 31 January, we updated our ‘Census 2021’ section of StatsWales to include data for Wales in relation to demography and migration. This includes data on country of birth, passports held, legal partnership (marital) status, and UK armed forces veterans.

Rebasing Wales’s population following Census 2021: additional information article

In April, we are planning to publish a statistical article that looks in further detail at the rebased mid-year population estimates for Wales following Census 2021. This will be accompanied by a similar publication by the ONS, focussing on the rebased estimates for Wales and England.

Welsh language statistics

For information on Welsh language statistics, please see the Statistics Wales quarterly update.

Contact details

Martin Parry

Telephone: 0300 025 0373



Telephone: 0300 025 8099