How many migrants are there in the UK? Where do migrants live? What countries do migrants to the UK come from? This briefing provides an overview of the UK’s foreign-born population.
- In 2021, people born outside the UK made up an estimated 14.4% of the UK’s population, or 9.5 million people.
- Compared to the UK born, migrants are more likely to be aged 26 to 64, and less likely to be children or people of retirement age.
- London has the largest number of migrants among all regions of the UK, 3,346,000 – or 37% of the UK’s total foreign-born population.
- In the year ending June 2021, India was – once again – the most common country of birth for migrants (896,000) in the UK. It regained the top place from Poland, after a number of Polish-born people left the UK. Poles still represented the biggest non-British nationality (696,000).
- About half of non-EU migrants in the year ending June 2021 said they came to the UK for family reasons, while the most common reason for migration among EU migrants was work.
- In 2021, people born outside the UK made up an estimated 14.4% of the UK’s population, or 9.5 million people.
Understanding the Evidence
This briefing defines the migrant population as the foreign-born population in the UK. Where relevant, the briefing also provides figures for foreign citizens residing in the UK, as well as for recent migrants – defined as foreign-born people who have been living in the UK for five years or less. ... Click to read more.
Definitions have a significant impact on the analysis of the number of migrants in the UK and there is significant overlap between those who belong to the foreign-born group and those who belong to the foreign-citizen group. For more information about how migrants are defined, see the Migration Observatory briefing, Who Counts as a Migrant?
Most of the data in this briefing are taken from the Office for National Statistics’ Annual Population Survey (APS). The APS has some important limitations. Some people are excluded, such as residents of communal establishments like hostels and certain students in halls of residence, and other groups may be under-counted due to survey non-response. Its response rate has declined over time, and is now below 50% (ONS, 2016); this means that people who are more likely not to respond to the survey may be under-counted. ONS analysis based on the Census suggests that non-response is a greater problem among people born outside of the UK (Weeks et al, 2013).
Due to the coronavirus pandemic, face-to-face interviewing was suspended on the 17 March 2020 and respondents have been interviewed by telephone ever since. This change in the mode of data collection impacted the survey response rate, which has been significantly lower, and the non-response bias (that is, the profile of people who do not participate in the survey has changed). To increase the response rate, the ONS introduced the ‘knock to nudge’ system in April 2021, where interviewers encourage respondents to provide their phone number or arrange an appointment by knocking on their door (Office for National Statistics, 2021a)
The ONS provided revised data with new population weights in 2021 in an effort to address the impact of the pandemic (see Office for National Statistics, 2021b). The Office for National Statistics (ONS) and the Migration Observatory have also published several pieces discussing the effects of the pandemic on the LFS/APS data collection and the reliability of the population estimates derived from those surveys (e.g. Athow, 2021; Sumption, 2021). Note that figures for 2021 are calculated from the APS microdata whereas previous figures are from published ONS tables.
The terms EU-8 and EU-2 refer to migrants from countries that joined the EU in 2004 and 2007, respectively. EU-8 refers specifically to migrants from Hungary, Latvia, Lithuania, Poland, Estonia, the Czech Republic, Slovakia and Slovenia while EU-2 refers to migrants from Romania and Bulgaria.
This briefing focuses on the population of migrants living in the UK. For more information about migration to and from the UK, see the Migration Observatory briefing, Net migration to the UK.
As of the year ending June 2021, people born outside the UK made up an estimated 14.5% of the UK’s population, or 9.6 million people
The size of the foreign-born population in the UK increased from about 5.3 million in 2004 to over 9.5 million in 2021 (Figure 1). The growth of the foreign-born population appears to have slowed as a result of the Covid-19 pandemic, but currently available estimates suggest that net migration remained positive despite a net outflow of EU citizens (see the Migration Observatory briefing, Net migration to the UK). For discussion about early indicators of the impact of the pandemic on UK migration flows, see our commentary “New Measures: COVID-19, the end of the International Passenger Survey, and the November 2020 migration statistics.”
Although the numbers of EU migrants increased more rapidly than non-EU migrants for most of the 2000s and 2010s, the non-EU foreign born still make up a majority of the foreign-born population. In 2021, an estimated 36% of migrants were born in the EU. More information about EU migration is available in the Migration Observatory briefing, EU Migration to and From the UK.
The share of foreign-born people in the UK’s total population increased from 9% from 2004 to 14% in 2021 (Figure 2). During the same period, the share of foreign citizens rose from 5% to just under 10%.
Over time, the foreign-born share of the population typically rises more than the non-citizen share, because many migrants become UK citizens over time. EU migrants have traditionally been less likely to naturalise as British citizens than people from non-EU countries. This remained the case after the 2016 referendum on EU membership despite an increase in citizenship applications among EU citizens. The non-citizen population also includes some children born in the UK: in 2021, there were an estimated 350,000 UK-born children (under the age of 18) who were EU nationals and 118,000who were non-EU nationals, according to the Annual Population Survey. For more information about citizenship and naturalisation of UK migrants, see the Migration Observatory briefing, Citizenship and Naturalisation for Migrants in the UK. For more about the children of migrants read the Migration Observatory briefing: Children of migrants in the UK.
Compared to the UK born, migrants are more likely to be age 26 to 64, and less likely to be children or people of retirement age
Compared to the UK-born population, migrants are more likely to be adults aged 26-64 and less likely to be children or people of retirement age (65+) (Figure 3). In 2021, 70% of the foreign born were aged 26-64, compared to 48% of the UK born. The share of migrants in this age range varies by place of birth, with the highest percentage being for those born in the EU-8, EU2, Oceania, Africa, and Pakistan.
An estimated 20% of the UK-born were at least 65 years old in 2021, compared to 12% of migrants. Among the foreign-born, there is a lot of variation depending on the place of origin. Only 1% of people born in Romania or Bulgaria were aged 65+ compared to 18% of those born in the EU-14.
The overall shares of young people aged 16 to 25 are similar for those born in the UK (12%) and abroad (10%). The smallest percentage (5%) of young people are born in India, and the largest percentage (13%) originate from EU-8 countries.
Although the numbers of both female and male migrants have increased over time, women constitute a small majority of the UK’s migrant population. In 2019, about 53% of the foreign-born population were women or girls, according to APS data.
London has the largest number of migrants among all regions of the UK
Migrants are much more likely to live in some parts of the UK than others. In the year ending June 2021, about half of the UK’s foreign- born population (48% in total) were either in London (35% – 3,346,000) or the South East (13% – 1,286,000). Northern Ireland, the North East and Wales have a low share of the UK’s total foreign-born population, at 1–2% each (Figure 4). In comparison, the UK-born population is more evenly distributed. In mid-2021, only 10% of the UK-born population lived in London. For more information about the geographical distribution of the UK’s migrant population, see the Migration Observatory briefing, Where do migrants live in the UK? For detailed local-authority level data on migration, see the Migration Observatory’s Local Data Guide.
Figure 4 [Regional distribution of the UK’s foreign-born population, year ending June 2021]
India became the most common country of origin for migrants in the UK after a number of Poles left the UK
In the year ending June 2021, India, Poland and Pakistan were the top three countries of birth for the foreign-born, accounting respectively for 9%, 7% and 5% of the total (Figure 5). Poland dropped from the first place in 2018, during a period when net migration of people from countries that joined the EU in 2004 was estimated to be negative.
Nonetheless, Poland is still the top country of citizenship of foreign citizens (696,000), accounting for 12% of non-UK citizens living in the UK. This figure is also down since 2018, when it was estimated at 905,000. For more information on Polish and EU migration, please see the Migration Observatory briefing, EU Migration to and From the UK.
Just under half of non-EU-born migrants in the UK in the year ending June 2021 said they came to the country for family reasons, while the most common reason for migration among EU migrants was work
In the year ending June 2021, the most common reason that non-EU migrants gave for having originally moved to the UK was family (46% of non-EU born), followed by work (23%). The high shares of family migrants in the non-EU population in part reflects the fact that people who come on family visas are more likely to settle permanently than people who come on work or student visas – as explained in the Migration Observatory briefing, Settlement in the UK.
By contrast, EU migrants were more likely to have moved for work (48%). Work was a particularly important reason for migration for migrants from new EU member states, with 55% of EU-8 migrants and 58% of EU-2 migrants giving this reason.
For more information about family migration, see the Migration Observatory briefing, Family migration to the UK. More information about work visas and work migration is available in the briefing, Work visas and migrant workers in the UK. Information about international students can be found in the briefing, International student migration to the UK.
Evidence gaps and limitations
The APS has some limitations for estimating migrants in the UK. First, it does not measure the scale of irregular migration. Second, it does not provide information on asylum seekers. Third, the APS excludes those who do not live in households, such as those in hotels, caravan parks and other communal establishments. The APS is therefore likely to underestimate the UK population of recent migrants in particular. As noted above, there is also increased uncertainty about the estimates since 2020, due to problems collecting accurate data during the Covid-19 pandemic.
There are also some limitations in the APS variable on nationality, which currently does not collect full information on dual citizens. Where a respondent mentions more than one nationality, only the first nationality is recorded. This could mean that the number of non-British citizens is overestimated in this briefing. Respondents’ answer to the question ‘What is your nationality’ will not necessarily always reflect their legal citizenship, and will depend on how individuals understand the meaning of this term.
With thanks to Veronika Fajth for updating this briefing in 2022.