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Migrants in the UK: An Overview

04 Oct 2019

How many migrants are there in the UK? Where do migrants live? What countries do UK migrants come from? This briefing provides a basic overview of the UK’s foreign-born population.

  1. Key Points
    • In 2018, people born outside the UK made up an estimated 14% of the UK’s population, or 9.3 million people. An estimated 39% of migrants came from EU countries
    • Compared to the UK born, migrants are more likely to be adults aged 26 to 64, and less likely to be children or people of retirement age
    • London is the UK region with the largest number of migrants: 3.2 million foreign-born people in 2018
    • Poland is the most common country of birth and the most common citizenship among migrants in the UK
    • About half of non-EU migrants said they came to the UK for family reasons in 2018, while the most common reason for migration among EU migrants was work
  1. Understanding the Evidence

    This briefing defines the migrant population as the foreign-born population in the UK. Wherever relevant and indicated, 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. 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 of 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 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, n.d.).

    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 immigration and emigration to and from the UK, see the Migration Observatory briefing, Net migration to the UK.

In 2018, people born outside the UK made up an estimated 14% of the UK’s population, or 9.3 million people

The size of the foreign-born population in the UK increased from about 5.3 million in 2004 to almost 9.3 million in 2018 (Figure 1). The small decline in the estimated number of foreign-born people between 2017 and 2018 was not statistically significant, and other data sources suggest that net migration to the UK in recent years remains positive (see the Migration Observatory briefing, Net migration in the UK).

Although the numbers of EU migrants have increased more rapidly than non-EU migrants over the past decade, Non-EU foreign born still make up a majority of the foreign-born population. In 2018, 39% 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.

Figure 1

The share of foreign-born people in the UK’s total population increased from 9% from 2004 to 14% in 2018 (Figure 2). During the same period, the share of foreign citizens rose from 5% to 9%.

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, however, and it is not yet clear if and how this might change after Brexit when they no longer enjoy free movement rights. The non-citizen population also includes some children born in the UK: in 2018, there were an estimated 301,000 UK-born children (under the age of 18) who were EU nationals and 104,000 who 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, Naturalisation as a British Citizen.

Figure 2

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Compared to the UK born, migrants are more likely to be adults aged 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 2018, 69% 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 origin, with the highest percentage being for those born in Pakistan, Africa and EU-2 countries.

An estimated 21% of the UK-born were at least 65 years old in 2018, compared to 10% 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 17% of those born in EU-14.

The overall shares (12%) of young people aged 16 to 25 are the same for those born in the UK and abroad. The smallest percentage (6%) of youth are born in India, and the largest percentage (15%) originate from Other Asia and EU-8 countries.

Figure 3

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 2018, 52% of foreign born population were women, according to APS data.

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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 2018, about half of the UK’s foreign-born population (51% in total) were either in London (38%) or the South East (14%). Northern Ireland, Wales and the North East have a low share of the UK’s total foreign-born population, at 7.5%, 6.3% and 6.2% respectively. In comparison, the UK-born population is more evenly distributed. In 2018, only 10% of the UK-born population lived in London (Figure 4). 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

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Poland is the most common country of origin for migrants in the UK

Poland, India and Pakistan are the top three countries of birth for the foreign-born, accounting respectively for 9%, 9% and 6% of the total (Figure 5). Poland is also the top country of citizenship of foreign citizens, accounting for 15% of non-UK citizens living in the UK.

Figure 5

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About half of non-EU migrants said they came to the UK for family reasons in 2018, while the most common reason for migration among EU migrants was work

In 2018, the most common reason that non-EU migrants gave for having originally moved to the UK was family (49% of non-EU born), followed by work (20%). 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 (45%). Work was a particularly important reason for migration for migrants from new EU member states, with 55% of EU-8 migrants and 62% of EU-2 migrants giving this reason.

Figure 6

For more information about family migration, see the Migration Observatory briefing, Non-EU family migration in 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, Non-EU student migration to the UK.

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Evidence gaps and limitations

The APS has some limitations for estimating the dynamics of 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.

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.

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With thanks to Martin Ruhs and George Leeson for comments and suggestions in an earlier version of this briefing, and to Madeleine Sumption and Robert McNeil for the current version. Thanks to Luka Klimaviciute for research assistance.

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October 12, 2020


Dr Carlos Vargas-Silva
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