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Long-Term International Migration Flows to and from the UK

05 Jul 2016

This briefing provides an overview of Long-Term International Migration (LTIM) inflows (immigration), outflows (emigration), and the difference between the two (net migration) in the UK.

  1. Key Points
    • Net migration to the UK, the difference between immigration and emigration, was 333,000 in 2015. This represents an increase of 156,000 since 2012.
    • Inflows to the UK for 2015 were 630,000, comparable to the figure of 632,000 in 2014. Outflows from the UK were 297,000, compared to 319,000 in 2014.
    • There has been continuous net emigration of British citizens since at least 1991. In 2015, about 39,000 more British citizens moved abroad than came to live in the UK.
    • In 2015, non-EU citizens accounted for 44% of all inflows to the UK (including inflows of British citizens). The share of EU citizens in total inflows increased from 22% in 2004 to 43% in 2015.
    • Formal study and work are the most common reasons for migrating to the UK. In 2015, 167,000 people migrated to the UK for study purposes and an additional 308,000 migrated for work related reasons.


  1. Understanding the Evidence

    The analysis in this briefing is based on data from the Office for National Statistics (ONS) Long Term International Migration (LTIM). The primary data source for the LTIM estimates is the International Passenger Survey (IPS), but LTIM estimates also include adjustments based on other sources, such as the Home Office data on asylum seekers, the Labour Force Survey and the Northern Ireland Statistics and Research Agency international migration estimates. To accurately understand and interpret LTIM data, it is important to be clear about its underlying definitions and limitations. ONS uses the current international standard definition of a long-term international migrant to produce LTIM estimates: a person who moves to another country for at least one year (see “evidence gaps and limitations” below for further discussion). This excludes for example, tourism or short-term business related travel.

    Please note that the LTIM estimates used in this briefing are the revised estimates by the ONS. In early April 2014 the ONS published their report on the ‘Quality of Long-Term International Migration estimates from 2001 to 2011’, in which they revised the numbers of total net migration for the years 2001 to 2011. Based on the revision, total net migration between 2001 and 2011 was underestimated by 346,000. There is evidence that the underestimation was predominantly driven by an undercount of migration from the A8 Eastern European countries. However, a revised version of inflows and outflows as well as breakdowns by citizenship or reason for migration, etc., is not currently available. As a result, estimates relating to any breakdown of inflows, outflows, or different reasons for migrating will not match the total net balance.

Net migration to the UK, the difference between immigration and emigration, was 318,000 in 2014. This represents an increase of 109,000 since 2013 (when net migration was 209,000)

Net migration to the UK, the difference between immigration and emigration, was 333,000 in 2015. This represents an increase of 156,000 since 2012.

As shown in Figure 1, LTIM estimates suggest that since the early 1990s overall net migration to the UK has always been positive. In other words, the inflow of persons to the UK has been greater than the outflow. The headline net migration figures include people of all citizenships, including British citizens leaving the country or coming from abroad.

The latest available calendar-year figure for net migration is 333,000 in 2015 – an increase of 156,000 since 2012, 109,000 since 2013 and of 20,000 since 2014. It is comparable to the all-time high of 320,000 for the year ending in June 2005.

Between 2013 and 2015, inflows increased by 124,000, while outflows remained broadly stable.

During the 1990s, there was mostly a positive trend in net migration as these flows surged from minus 13,000 (i.e. net emigration) in 1992 to positive 163,000 in 1999. In the 2000s there was a significant increase in net migration that coincided with the 2004 EU enlargement and the opening of UK labour markets to workers from the so-called Accession 8 (A8) countries (Czech Republic, Estonia, Latvia, Lithuania, Hungary, Poland, Slovakia, and Slovenia), plus Malta and Cyprus. Migrants from new EU member states have accounted for a significant portion of recent net migration. However, there has also been a significant increase in net migration from EU-15 countries such as Spain and Italy, from a post-recession low point of 18,000 in 2010 to 79,000 in 2015.

Figure 1

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The share of EU citizens in LTIM inflows and net flows has increased.

In 2015 non-EU citizens (Commonwealth and ‘other’ categories) had a positive net migration of 188,000 (down slightly from 194,000 in 2014). They accounted for 44% of all inflows and 51% of non-British inflows.

EU citizens had a positive net migration of 184,000 in 2015 (up by 10,000 since 2014); they accounted for 43% of all inflows and 49% of non-British inflows. The share of EU citizens in inflows has been steadily increasing since 2004 (when it stood at 22%) and is much higher than the average for the 2000-2003 period (when it stood at about 13%). By contrast, the share of migrants from Commonwealth countries declined from 37% in 2004 to 26% in 2012 and then to 18% in 2015.

British citizens are the only group characterised by continuous net-emigration since 1991 (i.e. negative net migration). In 2015 there were 39,000 more British citizens moving abroad than coming to live in the UK. This is a substantial drop from 2011 when it stood at 70,000. Net emigration of British nationals peaked in 2006 at 124,000.

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Formal study and work are the most common reasons for migrating to the UK. In 2015, 167,000 people migrated to the UK for study purposes and 308,000 migrated for work

As people often move for a variety of reasons, it can be difficult to categorise migrants based on their reasons for migrating to the UK (see our ‘Mixed Migration: Policy Challenges’ primer for a discussion of mixed migration motivations. It is not hard to imagine, for instance, that someone is moving to the UK to join his/her spouse, work in the UK and to study. Therefore, it is important to keep in mind that while the ONS records the categories discussed below as mutually exclusive categories, this is clearly not always the case in practice.

Focusing on inflows, LTIM estimates suggest that 27% of people moving to the UK for at least one year (including British citizens) came for study purposes in 2015 (see Figure 2). This number has fallen from 238,000 in 2010.

Figure 2

At the same time, 308,000 migrants came for work related reasons in 2015. These people either had a definite job (28%) or came to look for a job (20%). Work reasons are now the most common reason for migrating to the UK, although formal study occupied this position between 2009 and 2012.

In 2015, 12% of migrants came to accompany or join a family member. This share has remained relatively stable over the past 10 years, though it represents a decline from a peak of 25% in 1994.

Work related reasons were the most common motives for leaving the UK (about 55% in 2015), with 33% of those leaving having a definite job abroad and 22% going abroad to look for work.

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The share of immigrants planning to stay for shorter periods (of 1-2 years) has increased since the 1990s

As Figure 3 shows, the share of immigrants planning to come for relatively short periods of 1 to 2 years rose steadily between 1993 and 2012 from 27% to 45% (and stood at 39% in 2014).

Figure 3

In 2014, 30% of migrants planned to stay for 3 or 4 years, while 11% were not sure. See the Evidence Gaps and Limitations section below for discussion of the limitation of the LTIM data in regards to using the intentions of migrants, which may or may not be realised in practice.

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The most popular destinations of people leaving the UK are non-EU countries

LTIM data also provide information about the ‘next intended’ country of residence of people leaving the UK, which may of course be different from their actual final destination. Moreover, the data will not reflect those instances in which individuals migrate to a country for a short time with plans of eventually moving to a third country.

The information reported in Figure 4 suggests that the most popular destinations of people leaving the UK in 2014 were non-EU countries (Commonwealth and others combined). Closer inspection of the data reveals that the most popular country for UK emigrants going to Commonwealth countries was Australia followed by countries in the Indian subcontinent. Because LTIM estimates do not make a distinction for naturalised British citizens, it is not possible to know how many of these emigrants were returning to a country of origin.

Figure 4

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Evidence gaps and limitations

Whether we should refer to all individuals who come to the UK as migrants for at least 12 months as ‘long-term’ migrants can be the subject of debate. For some people, the expression ‘long-term’ indicates a desire to settle or at least to spend a significant amount of time in the UK. However, the current ONS definition (which is the international standard) will place an individual who stays for 11 months and an individual who stays for 13 months in different categories, while a third individual who stays for 20 years will be in the same category as the individual who stays for 13 months.

In practical terms, the IPS asks individuals about their planned stay in the UK and abroad. The data thus captures individual intentions in order to measure inflows and outflows of migrants. Migrants’ plans for the future, e.g. the intention to stay in the UK for more than 12 months, may or may not be realised. The ONS uses different methods to address this challenge by, for example, adjusting for ‘visitor switchers’ (i.e. those whose original intention was to stay for less than one year but who subsequently stay longer) and for ‘migrant switchers’ (i.e. those who intended to stay for more than twelve months but left within a year).

Capturing information on migration is not the only purpose of the IPS, which collects data on a broad set of issues including tourists’ spending in the UK, towns visited and alcohol and tobacco purchases made, among others. Given that it is not an exclusively migration-focused survey, the sample of migrants in the survey is relatively small. As with any survey, there is a certain margin of error of the estimates. The ONS publishes the central estimate at the 95% confidence level, indicating the degree of uncertainty about this estimate. When evaluating changes, this allows for testing whether the given change is statistically significant or whether the estimate is too uncertain. Moreover, this uncertainty is especially relevant for the disaggregation of migrants across source countries given that the number of migrants interviewed from certain countries is small. As such, the ONS publishes the source of migrants using broad regional categories only.

It is also important to emphasize that the numbers and changes in net migration differ according to the source of estimates. For instance, it is possible to compare the dynamics suggested by these estimates with that of other data sources such as the Annual Population Survey (APS). LTIM estimates provide information on net migration flows (i.e. difference between immigration and emigration), while the APS provide information on the stock of migrants. The changes in the stock of migrants should reflect the level of net migration; however, there are significant differences between the estimates.

Finally, it is essential for the reader to keep in mind that the total net migration figures have been revised upwards for the years that span between 2001 and 2011. This change in estimates came alongside a published report by the ONS in early April 2014. Based on the revision, total net-migration between 2001 and 2011 was underestimated by 346,000. There is evidence that the underestimation was predominantly driven by an undercount of migration from the A8 Eastern European countries. However, the figures have not been revised to reflect undercounts in inflows and outflows and there are no revised figures with breakdowns by reason for migration or citizenship. In simple terms, if for example one is looking at inflows and outflows for these years, the difference will not match the revised net balance of that year. This also applies to any other breakdown beyond the total net balance for each year between 2001 and 2011.

Thanks to Ann Singleton for helpful comments and suggestions in an earlier version of this briefing

Further Reading

  • Migration Advisory Committee. “Limits on Migration: Limits on Tier 1 and Tier 2 for 2011/12 and Supporting Policies.” UK Border Agency, London, 2010.
  • Migration Observatory Election 2015 Briefing – Why do International Migrants Come to the UK?
  1. Media Coverage

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July 5, 2017


Dr Carlos Vargas-Silva

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