Irregular migration to the UK, year ending March 2024
Published 23 May 2024
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1. Introduction
This statistical release from the Home Office provides an overview of people who come to the UK irregularly. It includes those arriving on a small boat across the English Channel (a ‘small boat arrival’), along with some other groups arriving without prior lawful permission.
Some people may also enter the UK on regular routes and their status subsequently becomes irregular (for example, if they overstay their visa). Others may enter through an irregular method and remain undetected or will be detected some time after their arrival. Others may enter irregularly but obtain ‘regular’ status (for example, following an application for asylum).
The statistics presented here relate to the number of people detected on, or shortly after, arrival to the UK through various irregular methods of entry. They do not include all those who enter the UK through irregular methods, nor the number of irregular migrants currently present in the UK. It is not possible to know the exact number of people currently resident in the UK without permission, nor the total number of people who enter the UK irregularly.
Some people seek to enter the UK without valid permission but are prevented from reaching the UK border (for example, at the juxtaposed controls in France and Belgium, or further afield, if prevented from travelling). Prevented attempts are not reported in this release. Any counts of attempted entries may relate to multiple attempts by the same individual, and therefore will not relate to numbers of people.
Additional information is provided in the ‘About the statistics’ section and in the ‘user guide’.
2. Irregular arrivals
Not all arrivals will be detected and the proportion of arrivals detected will vary by method. Therefore, it is not advisable to directly compare recorded detections on different methods of entry. However, some broad trends can be observed.
In the year ending March 2024, there were 38,546 irregular arrivals, 28% fewer than in the year ending March 2023, and 81% of these arrived by small boats.
Small boats have been the predominant recorded method of entry for irregular arrivals since 2020, when entries by this method increased rapidly and entries by other methods declined (likely in part due to the COVID-19 pandemic making other methods of entry, such as air or ferry, less viable). Small boat arrivals are also the most visible of the irregular methods of entry, so the most likely to be recorded.
Small boat arrival numbers are subject to seasonal fluctuations due to changes in the weather, typically with peaks in warmer summer months (for example, quarter 3 (Q3), July to September, see figure 1). Comparisons of arrivals between the same months in different years may also be affected by differences in conditions. As a result we do not make comparisons between shorter periods where arrival numbers are low and may fluctuate considerably.
Figure 1: Detections at the UK border, by method of entry, January 2018 to March 2024
Source: Irregular migration to the UK - Irr_D01
2.1 Nationalities and demographics of arrivals
Since January 2018, 70% of people arriving irregularly have been adult males aged 18 and over.
Since 2018 just under one-fifth (19%) of irregular arrivals have been children aged 17 and under.
Financial, social, physical and geographical factors may influence the method of entry individuals use and the types of individuals detected arriving through each one. These factors may also change over time and could have an effect on any analysis of trends (see Irr_D01).
Around one-sixth (17%) of irregular arrivals in the year ending March 2024 were Afghans, who were in the top 5 for all 4 entry methods.
However, the number of Afghan small boat arrivals has decreased by 36% in the year ending March 2024 (figure 2).
Table 1: Top 5 nationalities arriving for each irregular method of entry, in the year ending March 20241,2
| Rank | Small boat arrivals (% of total) | Inadequately documented air arrivals (% of total) | Recorded detections in the UK (% of total) | Recorded detections at UK ports (% of total) |
|---|---|---|---|---|
| 1 | Afghanistan, 5,662 (19%) |
Iran, 959 (27%) |
Sudan, 714 (21%) |
Albania, 60 (15%) |
| 2 | Iran, 3,639 (12%) |
Afghanistan, 350 (10%) |
Eritrea, 587 (17%) |
Sudan, 48 (12%) |
| 3 | Turkey, 3,244 (11%) |
Georgia, 314 (9%) |
Iraq, 477 (14%) |
Afghanistan, 43 (11%) |
| 4 | Eritrea, 2,875 (10%) |
Sri Lanka, 308 (9%) |
Iran, 401 (12%) |
India, 30 (8%) |
| 5 | Iraq, 2,567 (9%) |
Turkey, 307 (9%) |
Afghanistan, 261 (8%) |
Vietnam, 30 (8%) |
Source: Irregular migration to the UK - Irr_D01
Notes:
- The top nationalities are those with the highest number of irregular arrivals for each separate method of entry in the year ending March 2024.
- Excludes small boat arrivals labelled as ‘Not currently recorded’ in the detailed and summary tables that accompany this release, for whom information on nationality is not yet available.
In the first 3 months (January to March) of 2024 there were 1,060 Vietnamese small boat arrivals, more arrivals than any other nationality. Although arrivals of Vietnamese nationals have been growing, Vietnam was ranked only the seventh amongst small boat nationalities in the year ending March 2024 and therefore is one of the ‘All other nationalities’ in figure 2 below (along with 76 others for the year ending March 2024).
Figure 2: Top nationalities arriving by small boats, April 2021 to March 20241,2
Source: Irregular migration to the UK - Irr_D01
Notes:
- The top nationalities are those with the highest number of small boat arrivals since April 2021.
- Excludes arrivals where information on nationality was not recorded in the dataset.
3. How many people were detected arriving by small boats?
3.1. Number of people arriving by small boat
Statistics on small boats include individuals who were detected on arrival to the UK, detected in the Channel and subsequently brought to the UK, and those encountered in the UK who were suspected of having arrived on a small boat within the previous 72 hours. They do not include any people who arrived on larger vessels (such as on a ferry), those who arrived in the UK undetected or those prevented from departing France or intercepted by French authorities and returned to France (see the ‘user guide’ for more details).
In the year ending March 2024, 31,079 people arrived by small boats, 31% fewer than in the year ending March 2023 (45,019) (and 32% fewer than the peak of 45,774 in 2022).
Although the comparison for the full year ending in March 2024 shows a year-on-year decrease, provisional data for the first 3 months of 2024 shows that the number of small boat arrivals from January to March 2024 was 43% higher than the same period in 2023. However, this period is one when arrival numbers are normally low due to the bad weather conditions and numbers of arrivals fluctuate considerably. Therefore, any comparison over this short period is unlikely to be robust.
Figure 3: Cumulative number of people arriving by small boats each month, January 2021 to March 2024
Source: Irregular migration to the UK summary tables - Irr_02a
3.2. Number of boats and people per boat
The average number of people per boat increased to 50 people per boat in the year ending March 2024, compared with an average of 43 people per boat in the year ending March 2023.
Figure 4: Number of small boats arriving and average number of people per boat, January 2018 to March 2024
Source: Irregular migration to the UK summary tables - Irr_02a
In the year ending March 2024, 625 small boats arrived without permission, 41% fewer than the 1,054 in the year ending March 2023. Although the number of people and boats arriving have decreased, the average number of people per boat has continued to increase (figure 4 and table 2).
Table 2: Average number of people per boat, year ending March 2019 to year ending March 2024
| Year ending March 2019 | Year ending March 2020 | Year ending March 2021 | Year ending March 2022 | Year ending March 2023 | Year ending March 2024 | |
|---|---|---|---|---|---|---|
| Average number of people per boat | 8 | 12 | 14 | 29 | 43 | 50 |
4. Asylum claims from small boat arrivals
The majority of small boat arrivals claim asylum, but small boat arrivals accounted for just over one-third of the total number of people claiming asylum in the UK in the year ending March 2024.
In the year ending March 2024, 99% (29,510 of 29,909 arrivals) had an asylum claim recorded either as a main applicant or dependant, as of 16 April 2024 (table 3). Almost all (95%) of the asylum applications from small boat arrivals made in the year ending March 2024 were still undecided at the end of March 2024.
More recent arrivals will naturally have a higher proportion of asylum applications awaiting a decision, as less time has passed to allow for applications to be processed. For all small boat asylum applications since 2018, 37% (37,246) are awaiting a decision.
The majority of the cases still awaiting a decision will relate to people who arrived on or after 28 June 2022, following the actions taken to clear the ‘legacy’ backlog of older asylum applications and subsequent legal changes. Cases where the applicant arrived irregularly since 7 March 2023 fall under the criteria for the Illegal Migration Act. Since 20 July 2023, when the Illegal Migration Bill received royal assent and became the Illegal Migration Act, there have been no grants of asylum to anyone who arrived by small boat on or after this date.
Of those whose asylum case has had an outcome since 2018, over half (56%) have been granted.
The overall asylum grant rate for small boat arrivals between 2018 and March 2024 is 72%, but there is a high number of withdrawals and if those are factored in then only 56% of cases with an outcome received a grant.
The number of small boat arrivals with an initial decision on their asylum claim as of March 2024 is subject to change in future publications as more individuals have their claims processed. Most of the asylum applications granted to small boat arrivals who arrived in the year ending March 2024 were aged 17 and under.
Table 3: Small boat arrivals applying for asylum and initial decision outcomes on their applications, 2018 to March 20241,2,3,4
| January 2018 to March 2023 | Year ending March 2024 | |
|---|---|---|
| Small boat arrivals | 87,788 | 29,909 |
| Asylum applicants (people) | 80,448 | 29,510 |
| Applications (main applicants only) | 72,581 | 26,821 |
| Applications awaiting a decision | 11,707 | 25,539 |
| Applications withdrawn | 13,172 | 1,041 |
| Applications which received an initial decision (% of applications) | 47,702 (66%) | 241 (1%) |
| of which: | ||
| granted refugee status or other leave (grant rate) |
34,492 (72%) | 50 (21%) |
| refused | 10,216 | 186 |
| not considered on third country grounds | 2,994 | 5 |
Source: Irregular migration to the UK - Irr_D02 and Irr_D03
Notes:
- Applications awaiting a decision, withdrawn, and which received a decision are a count of applications, not people (meaning they exclude dependents).
- Applications granted includes grants of refugee status, humanitarian protection and other forms of leave.
- Grant rate is the percentage of applications that resulted in a grant of protection or some form of leave at initial decision, excluding withdrawn applications.
- Total small boat arrivals in this section on asylum claims will differ slightly from the total small boat arrivals cited elsewhere in this publication due to differences in the dates on which data was extracted.
For more details on people applying for asylum, see the ‘How many people do we grant protection to?’ chapter of the Immigration system statistics quarterly release.
5. Potential victims of modern slavery
Modern slavery includes any form of human trafficking, slavery, servitude or forced labour. Potential victims of modern slavery in the UK are referred to the National Referral Mechanism (NRM). Statistics on modern slavery referrals show the overall number of NRM referrals in January to March 2024 (4,524) increased 9% compared to October to December 2023 (4,134). The number of NRM referrals has increased steadily since April 2023. For more information on NRM referrals, see the ‘user guide’.
5.1 Small boat arrivals with modern slavery referrals
A small proportion of small boat arrivals have been identified as potential victims of modern slavery.
Of the 117,697 small boat arrivals since 2018, fewer than one in 10 (9% or 11,110 people) had been referred to the NRM.
The number of small boat arrivals in each year with NRM referrals is likely to increase, as people have more time to identify as a potential victim and be referred into the NRM.
5.2 Outcomes of small boat modern slavery referrals
Of the 2,630 conclusive grounds decisions issued since 2018, 52% were negative, meaning they are not deemed to be a victim of modern slavery.
Most small boat arrivals with NRM referrals have received a reasonable grounds decision, but not yet received a conclusive grounds decision (table 4). This is because most reasonable grounds decisions are issued within 5 days of the referral, but conclusive grounds decisions can take considerably longer. More recent periods will naturally have a higher proportion awaiting a conclusive grounds decision, as less time has passed to allow for a decision to be made.
Table 4: Outcomes of small boat modern slavery referrals, 2018 to March 20241,2,3,4,5
| January 2018 to March 2023 | Year ending March 2024 | |
|---|---|---|
| Small boat arrivals | 87,788 | 29,909 |
| Arrivals with NRM referrals | 9,342 | 1,768 |
| Reasonable grounds (RG) decisions | 8,455 | 1,590 |
| Positive (%) | 5,790 (68%) | 624 (39%) |
| Negative (%) | 2,665 (32%) | 966 (61%) |
| Awaiting RG decision | 132 | 124 |
| Conclusive grounds (CG) decisions | 2,437 | 193 |
| Positive (%) | 1,178 (48%) | 79 (41%) |
| Negative (%) | 1,259 (52%) | 114 (59%) |
| Awaiting CG decision | 3,328 | 431 |
| Referrals withdrawn / closed | 758 | 49 |
| Awaiting reconsideration | 22 | 5 |
Source: Irregular migration to the UK - Irr_D04 and Irr_D05
Notes:
- The time periods relate to the date of the small boat arrival, not the date of NRM referral or decision. NRM referrals can be made at any stage after arrival into the UK.
- Individuals referred to the NRM receive decisions on 2 grounds: reasonable grounds and conclusive grounds. Therefore, individuals will be counted in multiple groups shown in the table. For example, those who are awaiting, or have received, a conclusive grounds decision will have previously received a positive reasonable grounds decision. Some individuals who are awaiting reconsideration and some of those whose referrals have since been withdrawn / closed will also have previously received a positive reasonable grounds decision.
- Referrals withdrawn / closed includes some cases where contact with the individual has been lost. These may be reopened if the individual makes contact in future.
- Cases awaiting reconsideration includes both those awaiting a new reasonable grounds decision and those awaiting a new conclusive grounds decision.
- Total small boat arrivals in this section on asylum claims will differ slightly from the total small boat arrivals cited elsewhere in this publication due to differences in the dates on which data was extracted.
6. Returns of small boat arrivals
The data presented below shows the number of enforced and voluntary returns of small boat arrivals. Returns figures, especially voluntary returns, may be revised upwards as it can take time for the Home Office to become aware of such departures and for them to be recorded on the system.
Between 2018 and March 2024, there have been 3,168 returns of small boat arrivals, or 3% of all small boat arrivals, 2,178 of these returns occurred in the year to March 2024.
Numbers of returns are low relative to numbers of people arriving irregularly by small boat, because most of these irregular migrants claim asylum on arrival. Those claims that are unsuccessful must still undergo substantive consideration, or consideration under inadmissibility rules, before any steps can be taken to arrange a return.
In year ending March 2024, 89% of small boat returns have been Albanian nationals. This follows the UK-Albania joint communique, signed on 13 December 2022 in an effort to deal with illegal migration and increase the number of people returned to Albania.
Figure 5: Returns of small boat arrivals, January 2018 to March 2024
Source: Irregular migration to the UK summary tables - Irr_02e
For more information on returns, see the ‘How many people are detained or returned?’ chapter of the Immigration system statistics quarterly release.
7. About the statistics
The underlying casework systems on which this data is based are undergoing a process of change and therefore the published numbers may change in future quarters.
These statistics should not be used to infer the size of the irregular population in the UK, nor the total number of people entering the UK irregularly. For a number of reasons, it is not possible to know the exact size of the irregular population, or the number entering irregularly, and so we have not produced any official estimates for this number.
This is because:
- some people will successfully evade border controls and remain in the UK undetected
- some people may enter the UK on regular routes and their status subsequently becomes ‘irregular’ – for example, if they overstay a visa (it should be noted that there are a number of ways in which a person’s departure from the UK may legitimately not be recorded on the system)
- the data sources available count the number of recorded detections - in some instances the same person may be detected multiple times, either for the same method of entry or across different methods of entry (such individuals will be counted multiple times in the statistics)
- some people may enter the UK irregularly but obtain ‘regular’ status – for example, following a successful asylum application
Figures on detections may be affected by the levels of operational activity at the border and overseas, so should not be used to infer levels of irregular migration. Changes in detection could be a result of changes in operational activity as well as changes in the number of people attempting to enter the UK irregularly and recording practices.
Data on detections does not include those prevented from reaching the UK border (for example, those prevented from boarding transportation at their port of embarkation or where their concealment in a vehicle has been detected prior to arrival in the UK).
For more information on the data in this release, please see the ‘user guide’.
8. Data tables
Data referred to here can be found in the following tables: