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Who Counts as a Migrant? Definitions and their Consequences

23 Feb 2024

This briefing considers the different ways in which one can understand who counts as a migrant in the UK and the implications of using different definitions.

  1. Key Points
    • There are many different ways to interpret the term ‘migrant’ and no definition of a ‘migrant’ in law
    • Different data sources define migrants in different ways. Migrants may be defined as foreign-born, foreign nationals or people who have moved to the UK for a year or more, among other possibilities
    • Different definitions have significant consequences for how many and which types of ‘migrants’ are counted as entering and living in the UK. This in turn affects analysis and understanding of the impacts of migration
    • The use of the term ‘migrant’ in the public discourse is extremely loose and often conflates issues of immigration status, race, ethnicity and asylum. Misuse of the terminology can produce inaccurate reporting and complicate policy debates

There are many ways to interpret the term ‘migrant’

When counting migrants and analysing the consequences of migration, who counts as a migrant is of crucial importance. Yet there is no consensus on a single definition of a ‘migrant’. Migrants might be defined by foreign birth, by foreign citizenship, or by their movement into a new country to stay temporarily (sometimes for as little as one month) or to settle for the long term. In some instances, children who are UK-born or UK nationals but whose parents are foreign-born or foreign nationals are included in the migrant population.

While dictionary definitions sometimes distinguish ‘immigrants’ – people who are, or intend to be, settled in their new country – from ‘migrants’ who are temporarily resident, ‘immigrant’ and ‘migrant’ (as well as ‘foreigner’) are often used interchangeably in public debate and even among research specialists. In some scholarly and everyday usage, people who move internally within national boundaries are called migrants. No two definitions of migrant are equivalent, and their effects on our understanding of migration and its impact are significant.

There is no definition of ‘migrant’ or of ‘immigrant’ in law. From a legal perspective, there is a key distinction between people who are ‘subject to immigration control’, who need permission to enter or to remain in the UK and those who are not. While the UK was part of the EU, EU nationals were not subject to immigration control, although they were often described as migrants.

But if a migrant is not necessarily someone ‘subject to immigration control’, what alternative definitions exist?

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Migrants in datasets

Datasets for understanding migration in the UK use – and allow for analyses based on – different definitions of ‘migrant,’ as shown in Table 1. These vary along several dimensions.

Country of birth: Analyses of the impacts of migrants on the UK economy usually define migrants as ‘foreign-born’. These studies may rely on the Census, Labour Force Survey (LFS) and Annual Population Survey (APS), which are comprehensive sources of data on workers and labour markets in the UK. Although this is an intuitive definition of a migrant, many foreign-born people are also British citizens. They are not subject to immigration control, nor do they count as migrants when migration is defined by nationality.

Nationality: ‘Migrant’ alternatively may be defined as ‘foreign national’, for example, in Census data on the passport a person holds or LFS and APS data on self-reported nationality. This definition is viewed as more problematic than country of birth, as a person’s nationality can change. If self-reported, ‘nationality’ may be interpreted as describing an elective affinity dependent on social and cultural factors and personal feelings rather than legal status. UK nationals with other citizenships further complicate this picture, as often only one of their citizenships is captured in the data source.

Length of stay: In its analyses of migration into and out of Britain, the Office for National Statistics (ONS) uses the UN definition of ‘long-term international migrant’: “A person who moves to a country other than that of his or her usual residence for a period of at least a year [….] so that the country of destination effectively becomes his or her new country of usual residence (UN 1998)”. However, measuring migration according to this definition of ‘long-term migrant’ poses several challenges. First, for any given individual arriving in the UK, we do not know how long they will stay. This complicated pre-pandemic attempts to measure migration based on the International Passenger (IPS) survey, which asked respondents how long they intended to move. It also complicates more recent migration estimates based on administrative records since, to produce timely estimates, ONS must make assumptions about whether people who arrive in or depart from the UK are likely to do so for more than a year.

Table 1

Definitions of migrant as represented in government data sources

Type of definitionONS admin-based migration estimatesLFSHome Office visa dataCensus
UN definition (at least one year)Yes (but most recent estimates based on assumptions about duration of stay)Yes (can approximate based on length of stay)No (non-EEA data exists but not usually published)Yes
Dictionary: "enter in order to settle"NoNoNo (but separate data available on settlement grants)No
Subject to immigration controlNo (does not separately identify people with indefinite leave to remain)No (does not identify people with indefinite leave to remain)YesNo (does not identify people with indefinite leave to remain)
Non-UK citizensYes (measures for EU are based on original nationality at the point of applying for a NINo)Yes (but only one nationality captured)YesYes (based on passports held)

These different definitions of ‘migrant’ are not interchangeable. For example, people who are foreign-born are not all foreign nationals; likewise, some foreign nationals may have lived in the UK for decades while others have resided in the UK for only a year. Perhaps most importantly, not all foreign-born UK residents are subject to immigration control. Some are the children born abroad of UK national parent(s) – e.g. service personnel. Others are long-term British residents who have acquired citizenship.

In addition, the term ‘migrant’ is sometimes distinguished from, and sometimes includes, foreign nationals who are seeking asylum in the UK. These represent a small proportion of overall entrants to the UK, though they have attracted a great deal of public and policy attention.

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Why does it matter? Data and analysis

Definitions affect data, including measures of the number of migrants living in the country at any given time and people moving into or out of the country.

For example, in Apr-Jun 2023, 19% of people employed in the UK were foreign-born, while 13% were foreign nationals (ONS Employment by country of birth and nationality). Thus, if migrants’ share of the labour market is a concern for policy-makers, that share appears significantly larger if one considers all foreign-born workers rather than foreign nationals.

Different definitions of ‘migrant’ also yield different estimates of the net balance of migrants moving to and from the UK. Current official government net migration estimates include some groups that would be excluded under other definitions. They include people of all nationalities as migrants, including UK nationals, so long as they are crossing national boundaries with the intention of staying for at least one year. Yet UK nationals obviously would not be considered migrants if defining migrants as ‘foreign nationals.’ The British nationals included in net migration statistics reduce the headline net migration figure since more British nationals depart than arrive (You can see how including or excluding British citizens affects total numbers by selecting the “including British” or “excluding British” options in Figure 1).

Figure 1

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Definitions and public debate

Who is a ‘migrant’ is often unclear in public debate. For example, migrants are often conflated with ethnic or religious minorities, and some people consider asylum seekers to be a subset of migrants while others do not (Saggar and Drean 2001, Crawley 2009, Beutin et al. 2006, Baker et al. 2008).

Media discourses commonly use such terms interchangeably, particularly in tabloid newspaper discussions of asylum (Baker et al. 2008). When asylum applications in European countries increased sharply in 2015 and 2016, media coverage often used the term ‘migrants’ pejoratively to refer to economic migrants in contrast to ‘genuine refugees’. Guidelines on recommended terminology for UK media reporting on migration can be found in the Reporting on Migration course developed by the Migration Observatory for the National Council for the Training of Journalists. A similar international glossary of migration terminology is also available in the International Centre for Migration Policy Development’s Reporting Migration handbook for journalists.

Meanwhile, the UK government’s official estimates of migration include asylum seekers in counts of migrants entering the UK while attempting to adjust the total numbers to exclude those who stay in the UK for less than a year and thus do not qualify as migrants defined by the length of stay.

Public opinion surveys on immigration attitudes reflect and may add to this confusion. Some surveys do not define their terms, leaving respondents to answer questions based on their own implicit definitions. Other surveys define an immigrant as someone who has come to the UK ‘to live’ (Ipsos-MORI) or ‘to settle’ (British Social Attitudes survey). These do not match the ONS definition, but they do fit the dictionary definition of immigration.

With such a variety of definitions and loose usage, there is no straightforward mapping of migration data onto the subjects of public debate and concern. For example, some evidence suggests that, when used by employers, ‘migrant’ may signify recent arrivals rather than foreign-born or even foreign nationals (Anderson and Ruhs 2010). For another, data gathered using a rigorous definition of ‘migrant’ may include groups who are not generally thought of in public debate as migrants – after all, famous British people such as Freddie Mercury and even Boris Johnson were foreign-born. Commonly used terms such as “expat”, which in the UK effectively means migrant but which is commonly used only when describing wealthier (and often white) migrants – can also muddy the waters by incorrectly suggesting that the term ‘migrant’ is only applicable to the poor or to ethnic minorities.

Finally, the Migration Observatory’s public opinion survey research, such as the 2023 “Thinking Behind the Numbers” analysis undertaken with Kantar Public and its 2023 briefing, UK Public Opinion toward Immigration: Overall Attitudes and Level of Concern, indicate that public concerns about migration tend to be strongly focused on particular groups – irregular arrivals, asylum seekers and low-skilled workers, in particular. Other types of immigrants, such as students and high-skilled workers, also are counted in immigration statistics but have been of less concern in public opinion.

The existence of multiple definitions poses a particular problem for consistency in public debate regarding the number or impact of migrants, as the same discussion might simultaneously draw on two different definitions accidentally or to suit the author’s purposes.

The definition of ‘migrant’ is not simply a technical problem but has an important effect on migration data and the analyses generated from the data. This, in turn, has an impact on public understanding and on policy debates. The confusion in public debate over the definition of ‘migrant’ poses challenges for government policy. Not all those who are considered ‘migrants’ in public debate and datasets are subject to immigration controls and policies. The definition of ‘migrant’ used by most official sources includes many British citizens and others whose rights to work and access to services in the UK are not determined by immigration controls alone.


  • Anderson, B. and M. Ruhs, “Migrant Workers: Who Needs Them? A Framework for the Analysis of Staff Shortages, Immigration, and Public Policy.” In Who Needs Migrant Workers? Labour Shortages, Immigration and Public Policy. Oxford: OUP, 2010.
  • Baker, P., C. Gabrielatos, M. Khosravinik, M. Krzyżanowski, T. McEnery, and R. Wodak. “A Useful Methodological Synergy? Combining Critical Discourse Analysis and Corpus Linguistics to Examine Discourses of Refugees and Asylum Seekers in the UK Press.” Discourse & Society19 (2008): 273-306.
  • Beutin, R., M. Canoy, A. Horvath, A. Hubert, F. Lerais, P. Smith, and M. Sochacki. “Migration and Public Perception.” Bureau of European Policy Advisers (BEPA), European Commission, Brussels, 2006.
  • Crawley, H. “Understanding and Changing Public Attitudes: A Review of Existing Evidence from Public Information and Communication Campaigns.” The Diana Princess of Wales Memorial Fund, London, 2009.
  • Saggar, S. and J. Drean. “Public Attitudes and Ethnic Minorities.” Cabinet Office Performance and Innovation Unit, London, 2001.
  • United Nations, “Recommendations on Statistics of International Migration, Revision 1,” Statistical Papers, Series M, No.58, Rev.1. Sales No. E.98.XVII.14., 1998.

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