How many migrants come to the UK?

Immigration has consistently been one of the most debated topics in UK politics in recent years, including during the 2024 general election campaign. 

Both Labour and the Conservative party have argued that current levels of immigration are too high, with Labour pledging in its election manifesto to “reduce net migration”. Migration was also reported as one of the key factors behind the disorder and rioting seen in the summer of 2024 (although as we and others wrote at the time, there are likely to have been a range of underlying causes).  

New figures published on 28 November 2024 estimate that net migration to the UK in the year to June 2023 was 906,000, a record level and far higher than previously thought. In the year to June 2024 it’s estimated to have fallen by 20%, to 728,000.

Our updated explainer looks at how migration to the UK is measured, how net migration has changed in recent years, and why it is expected to decrease in the coming years.

This explainer is one of a series Full Fact is publishing exploring a range of key political topics. We’ll be updating these articles on a regular basis—this article was last updated on 28 November 2024 and the information in it is correct as of then.

How is migration to the UK measured?

The Office for National Statistics (ONS) publishes estimates of long-term international immigration to, and emigration from, the UK based on administrative data. 

Subtracting the number of emigrants from the number of immigrants over a given period produces a figure for “net migration”. Net migration figures are perhaps those most commonly cited when talking about UK immigration policy, though Oxford University’s Migration Observatory says that the UK is “unusual in its choice to use net migration in policy debates as the main measure for discussing migration levels”.

The ONS defines a “long-term international migrant” as someone who has changed their country of usual residence for a period of at least a year (based on the UN’s recommended definition).

Current migration figures are based on a relatively new method of measuring annual migration flows (the number of long-term international migrants over a year) using administrative data. Because this method is still in development, the figures are designated as experimental statistics, or “official statistics in development”, by the UK Statistics Authority, as opposed to “national statistics”. As such, these migration statistics are often subject to revision, as the ONS explains here.

This data series goes back to June 2012. Previous estimates for long-term international migration were based on the International Passenger Survey (IPS), data from the Northern Ireland Statistics and Research Agency (NISRA) on international migration through Northern Ireland, and Home Office data. This data was published by the ONS from 1991 to 2020. An even earlier set of migration data, based solely on the IPS, dates back to 1964.

Net migration was at record levels last year…

According to the most recent estimates from the ONS, around 1.2 million long-term immigrants arrived in the UK in the year ending June 2024.

Over the same period, emigration from the UK totalled an estimated 479,000, meaning net migration to the UK was estimated to be 728,000. 

This represents a 20% fall compared to the same period the previous year, when net migration to the UK was 906,000—the highest level on record. But net migration in the year ending June 2024 was still more than three times higher than in the same period in 2019. 

As we’ve explained above these net migration estimates may be revised at a later date. For example, the initial estimate for net migration in the year ending June 2023 was 672,000—substantially lower than the revised estimate.

The ONS has previously described a “marked change” in immigration patterns since 2021, saying: “The ending of free movement of those from the European Union coupled with the introduction of a new immigration system in January 2021, easing of restrictions after the coronavirus (Covid-19) pandemic, and external events such as the war in Ukraine have all had an impact.”

In the decade prior to the Covid-19 pandemic net migration figures had fluctuated, but with the exception of 2020 (when travel patterns were heavily disrupted due the the pandemic), were consistently above 150,000 per year.

Based on ONS administrative data, annual net migration between 2012 and 2023 totalled 4.26 million.

Looking back further, IPS-based figures show net migration was broadly negative in the 1960s and 1970s (in other words, more people were leaving the country than arriving), but was increasing by the mid-1990s. Since 1994, more people have arrived in the UK than have left every year, and net migration has not fallen below 100,000 since 1998, other than during the pandemic.

However it’s not true, as Reform UK claimed during the election, that under the previous government more migrants arrived in the UK in two years than “between 1066 and 2010”.

… but is expected to fall considerably in the coming years

In its latest publication the ONS notes: “Our latest estimates indicate a fall in long-term net migration.”

ONS projections published in January estimated that annual net migration will decrease to around 315,000 from 2027/28, though note: “There is uncertainty over future directions and levels of international migration.”

The Office for Budget Responsibility (OBR) forecasts a similar decrease in the medium term.

Both these estimates are higher than previously forecast, but clearly considerably lower than current annual levels.

A number of explanations for this relative decrease have been put forward. In analysis published in December 2023, the Migration Observatory suggested that high levels of immigration in recent years would eventually lead to increased emigration, noting that “most migrants come to the UK for periods of only a few years, before emigrating again”.

The OBR says this is also a factor in its forecasts, stating in March: “The recent rise in immigration, especially among students, should lead to higher emigration in the short term.” It also considered the impact of policy changes introduced by the previous government restricting the ability of some immigrants to bring dependents, saying “immigration policy changes announced… will likely significantly reduce inflows in the near term”.

In its October forecast the OBR said it expected these changes to have “a slightly larger impact” than anticipated in its previous forecast.

In its latest publication the ONS says the fall in the year to June 2024 had been “driven by a decline in long-term immigration mainly because of declining numbers of dependants arriving on study visas”. It added: “Our most recent data points also show decreases in the number of people arriving for work-related reasons. This is consistent with visa data published by the Home Office, and in part reflects policy changes from earlier this year. 

“It is also driven by a rise in long-term emigration, most notably for those who came to the UK on study-related visas. This is likely a consequence of the large number of students who came to the UK post-pandemic now reaching the end of their courses.”

Finally, both the Migration Observatory and the ONS note that arrivals to the UK under humanitarian visas (primarily those from Ukraine and Hong Kong) have already decreased compared to 2022—when more than 160,000 people migrated to the UK via these routes—and are expected to “continue to decline in future”.

Despite the projected fall in annual net migration levels, however, immigration is still forecast to significantly increase the overall population of the UK over the next few years. As we wrote in June, the ONS has projected that total net migration over the next 12 years will be around 4.5 million.

Who is migrating to the UK?

In the year ending June 2024, the vast majority of people who migrated to the UK (86%) were non-EU+ nationals. Ten percent were EU+ nationals (the EU, plus Norway, Iceland, Liechtenstein and Switzerland), with the remaining 5% British nationals (note these percentages don’t sum due to rounding). The top-five non-EU+ countries of origin were India (240,000 migrants), Nigeria (120,000), Pakistan (101,000), China (78,000) and Zimbabwe (36,000).

Between 2012 (when the current set of ONS migration statistics was first published) and 2018, net migration to the UK from the EU exceeded non-EU national net migration. However the number of EU immigrants has been falling since 2016, and net migration from the EU has actually been negative since 2021 (when free movement ended following Britain’s exit from the EU), meaning more EU nationals are leaving the UK than arriving.

The latest ONS publication contains information on reasons for migration for non-EU+ nationals only. These figures show that the most common reason for migration to the UK among non-EU+ nationals was work (40%), followed by study (36%) .

Around 8% of non-EU+ nationals arrived in the UK to seek asylum.

The majority of migrants to the UK arrive here legally. However the number of migrants arriving via irregular methods (particularly by small boats) has increased considerably in recent years.

The ONS does not publish data on the proportion of migrants who arrive in the UK “legally” or “illegally”. However Home Office data shows that in the year ending June 2024 there were 38,784 irregular arrivals detected, 81% of whom arrived on small boats.

The vast majority of small boat arrivals claim asylum in the UK, and in the year ending June 2024 these claims accounted for over a third of asylum claims in the UK.The ONS has said “by its very nature it is impossible to quantify accurately the number of people who are in the country illegally”, but added: “While ONS data do not identify illegal migrants separately, many will be included in the data. Those who overstay their visa would have been counted in ONS immigration figures by the International Passenger Survey (IPS) when they originally entered the country and those who arrived illegally and then subsequently claimed asylum will also be included.”

How does migration to the UK compare internationally?

The Migration Observatory suggests that the UK has experienced “broadly similar levels of migration compared to other high-income countries, on average, over the past few decades”. 

Measuring the impact of migration by comparing the size of the foreign-born population as a percentage of the total population, the Observatory found that the share of foreign-born residents in the UK was similar to other ‘high-income’ countries such as the US and the Netherlands. Both the UK and US foreign-born population share was 14% in 2022, coming in at 15% in the Netherlands.

This was slightly higher than France (13%), but lower than Spain (16%) and Germany (17%).