22 May 2020
This notice provides the latest information on the error in the 2018-based national population projections, and the approach we will be taking.
The error was caused by incorrect processing of cross-border flows between Wales and England, resulting in the projected mid-2028 population for Wales being approximately 65,000 too low, and that for England being approximately 65,000 too high.
Following discussions with our partners in the devolved administrations, we have agreed the following:
We will publish corrected projections for Wales.
We will not change the projections for England, where the much larger population size, combined with the inherent uncertainty around the projections and underlying estimates, means a correction would not be statistically beneficial.
For the same reason, we will not change the 2018-based subnational population projections for England.
There will also be no change to the projections for Northern Ireland, Scotland or the UK as a whole.
We will publish an explanatory note with the correction, including advice for users.
We will replace all the open data projections for Wales by Thursday 11 June, making the new data available for analysis. We will publish the replacement summary tables by the end of June.
We apologise for any inconvenience caused by this error.
19 May 2020
We have identified some processing errors affecting the 2018-based national population projections. This mainly affects the flows between England and Wales. The impact of this is major. We will be replacing the product. We are consulting with our partners in the Welsh, Northern Irish and Scottish governments, and will provide a more detailed statement on our approach.
Note that because this issue only concerns flows between different parts of the UK, there is no meaningful impact on our projected totals for the UK as a whole.
18 June 2020
All summary tables for Wales have now been updated. The interactive population pyramids have not yet been updated; we will correct these by the end of June 2020.
27 January 2023
We advise users to use our 2020-based interim national population projections: year ending June 2022 estimated international migration variant dataset instead of the 2020-based interim national population projections (NPPs) published in January 2022. This is because this release includes more recent estimates of international migration in the averages used to calculate the short- and long-term international migration assumptions.
The variant NPP release uses updated international migration assumptions using expert advice and the latest provisional estimates of international migration. In combination, these have led us to increase our assumptions for future international migration. Net international migration in the UK is projected to reach an annual average of 245,000 from mid-2027 onwards, up from 205,000 in our earlier release. There is uncertainty over potential levels of international migration we may see in the coming years and the assumptions are based on the latest observed data and not forecasts.
Although these statistics have been produced broadly in line with our NPP production process, they are not National Statistics accredited as they are a data-only release that has been produced to meet user needs.
Decision-making on use of the 2018-based NPPs, 2020-based interim NPPs or the latest January 2023 data-only release will need to be guided by the intended use of the statistics.
Population projections are available in the release 2020-based interim national population projections: year ending June 2022 estimated international migration variant for: United Kingdom, Great Britain, England and Wales, England, Scotland and Wales. Northern Ireland projections have been excluded at the request of the Northern Ireland Statistics and Research Agency after it was determined that the UK assumptions made to generate this variant did not generate appropriate estimates for Northern Ireland. This was because of the country-level division of the provisional international migrant estimates. Projections for Northern Ireland are still available from our 2020-based interim national population projections principal projection.