Research from Oxford indicates pressure on the British economy as approximately 20 percent of the UK population was born overseas.
Office for National Statistics data indicates the number of UK residents who were born abroad increased by more than two million since the 2021 census.
According to figures released on Thursday by the ONS, around 13.1 million individuals living in the UK in mid-2024 were estimated to have been born outside the country.
Earlier ONS data shows the total UK population in mid-2024 was approximately 69.3 million.
This foreign-born population of 13.1 million equates to 19 percent of the overall total.
During the 2021 census, when data was collected in 2021 across England, Wales and Northern Ireland and in 2022 in Scotland, 16 percent of UK residents were born overseas.
Dr Ben Brindle, a researcher at the Migration Observatory at Oxford University, stated that the significant rise in net migration following the pandemic has brought the foreign-born population to its highest proportion of the UK population on record.
He noted that migration levels have decreased, but the economic effects depend more on the characteristics of those arriving or departing rather than the total number.
Migration of groups contributing positively or neutrally to the economy, such as skilled workers and spouses of students, has declined, while migration linked to asylum has remained elevated.
Given that refugees typically have lower employment rates and frequently require substantial government assistance, the recent composition of migration has likely become less beneficial from an economic standpoint, he suggested.
Net migration to the UK peaked at 944,000 in the 12 months ending March 2023.
The number has since declined substantially, reaching approximately 171,000 in the year to December 2025, according to the ONS.
Home Office statistics released on Thursday revealed a record 312,063 applications for British citizenship in the year to March 2026, representing an 18 percent increase from the previous period’s 263,440.
There were 236,512 citizenship grants in 2025/26, a 12 percent decline compared to the previous year’s 269,178, though still the second highest annual total since records began in 2005.
The Home Office indicated that 2025/26 grants primarily consisted of individuals obtaining citizenship through naturalisation following an earlier grant of indefinite leave to remain.
Naturalisation refers to the procedure through which a non-British adult can obtain British citizenship after completing a qualifying period of lawful residence in the UK and receiving indefinite leave to remain.
It also offers a pathway to British citizenship for those with settled status under the EU Settlement Scheme, as well as those with pre-settled status who have automatically secured permanent residence rights.