How many people come to the UK irregularly?
Published 27 February 2025
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This publication is available at https://www.gov.uk/government/statistics/immigration-system-statistics-year-ending-december-2024/how-many-people-come-to-the-uk-irregularly
Back to ‘Immigration system statistics, year ending December 2024’ content page.
Data relates to 2024 and all comparisons are with 2023 (unless indicated otherwise).
Additional information is provided in the ‘About the statistics’ section and in the user guide.
1. Irregular arrivals
Not all irregular 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 2024, there were 43,630 detected irregular arrivals, 19% more than in 2023, and 84% of these arrived on small boats.
Small boats have been the predominant recorded entry method for irregular arrivals since 2020, when detections on this method increased rapidly and detections on 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, and have remained high even as other routes have become more viable again.
Small boat arrival numbers are subject to seasonal fluctuations due to changes in the weather, typically with peaks in warmer summer months when crossing conditions are more favourable. Comparisons of arrivals between the same months in different years may also be affected by differences in weather conditions. As a result, we do not advise making comparisons between shorter periods where arrival numbers may fluctuate considerably.
Other irregular arrivals comprised: inadequately documented air arrivals (8%), recorded detections in the UK within 72 hours of arrival (7%), and recorded detections at UK ports (1%).
The number of inadequately documented air arrivals has been between 3,300 and 5,300 each year since 2018, except for 2020 and 2021 when numbers were lower due to COVID-19 travel restrictions.
There were 3,138 recorded detections in the UK in 2024, around two-thirds (62%) lower than the recent peak of 8,239 in 2019. Similarly, the number of recorded detections at UK ports in 2024 (326) has decreased 69% since 2018 (1,052).
Figure 1: Detections of irregular arrivals to the UK, by method of entry, January 2018 to December 2024
Source: Irregular migration to the UK detailed dataset, year ending December 2024 - Irr_D01
1.1. Nationalities and demographics of arrivals
Since January 2018, 70% of people detected arriving irregularly have been adult males aged 18 and over.
Since 2018, just under one-fifth (18%) of detected irregular arrivals have been children aged 17 and under.
Just under one-sixth (15%) of detected irregular arrivals in 2024 were Afghans, the nationality in the top 5 for all 4 entry methods.
Of the 6,339 Afghan irregular arrivals, 93% arrived on small boats (see section 2.3 for more detail on small boat arrivals by nationality).
Iranian, Eritrean, and Sudanese nationals were in the top 5 for multiple irregular methods of entry, with Iranians the most common nationality arriving inadequately documented by air (799 arrivals) and Sudanese nationals the most common nationality detected in the UK (719 detections). Albanians were the most common nationality detected at UK ports (64 detections); however, numbers were substantially lower than those arriving on small boats in 2022 (12,658 arrivals).
For most of the nationalities in Table 1, their most common irregular method of entry was on small boats, reflecting the size of that route (see section 2.3). However, for Sri Lankan and Georgian nationals, their most common irregular method of entry was by air.
Financial, social, physical and geographical factors may influence the method of entry individuals use and the types of individuals detected arriving. These factors may also change over time.
Table 1: Top 5 nationalities detected arriving for each irregular method of entry, in 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, 17% |
Iran, 24% |
Sudan, 23% |
Albania, 20% |
| 2 | Syria, 13% |
Sri Lanka, 11% |
Eritrea, 16% |
Sudan, 12% |
| 3 | Iran, 12% |
Georgia, 10% |
Iran, 13% |
India, 12% |
| 4 | Vietnam, 10% |
Stateless, 7% |
Iraq, 11% |
Afghanistan, 7% |
| 5 | Eritrea, 10% |
Afghanistan, 7% |
Afghanistan, 6% |
Eritrea / Pakistan / Turkey, 6% (each) |
| Total | 35,359 | 3,350 | 3,138 | 326 |
Source: Irregular migration to the UK detailed dataset, year ending December 2024 - Irr_D01
Notes:
- The top nationalities are those with the highest number of detected irregular arrivals for each separate method of entry in 2024.
- Excludes small boat arrivals labelled as ‘Not currently recorded’, for whom information on nationality is not yet available.
2. Small boat arrivals
2.1. Number of small boat arrivals
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 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’).
In 2024, 36,816 people arrived in the UK on small boats, 25% more than in 2023 (29,437).
Small boat arrivals were relatively low from 2018 to 2020, with 10,608 small boat arrivals across these 3 years. However, since 2021 there have been between 28,000 and 46,000 small boat arrivals each year, with the highest number of arrivals in 2022 (45,774).
Figure 2: Cumulative number of people arriving by small boats each month, January 2020 to December 2024
Source: Irregular migration to the UK summary tables, year ending December 2024 - Irr_02a
2.2. Number of boats and people per boat
The average number of people per boat has increased in each year, rising to 53 people per boat in 2024 compared with 49 people per boat in 2023.
Figure 3: Number of small boats arriving and average number of people per boat, January 2018 to December 2024
Source: Irregular migration to the UK summary tables, year ending December 2024 - Irr_02a
In 2024, 695 small boats arrived in the UK without permission, one third (33%) fewer than in 2021. However, as the average number of people per boat has increased to 53, compared to 28 in 2021, the number of people arriving by small boat was 29% higher in 2024 compared to 2021.
2.3. Nationalities of small boat arrivals
The top 5 nationalities arriving on small boats in 2024 accounted for 61% of all small boat arrivals. These nationalities were Afghan, Syrian, Iranian, Vietnamese, and Eritrean nationals.
Afghans were the top nationality arriving by small boat in 2024, with Afghan arrivals 7% higher in 2024 (5,919) compared to 2023. However, numbers remained lower than the peak of 9,088 Afghan arrivals in 2022 (Figure 4).
Albanians were the top nationality detected arriving by small boat in 2022, with 12,658 arrivals, but have declined to only 616 small boat arrivals in 2024. The substantial decrease in Albanian small boat arrivals since 2022 has in part been influenced by the collaboration between the UK and Albania and the signing of the agreement in December 2022 to deter and disrupt irregular migration and criminal networks.
Vietnamese nationals were the most common nationality detected arriving by small boat in the first half (January to June) of 2024, accounting for 17% of small boat arrivals in this period (2,248 arrivals). However, their numbers decreased in the second half of the year, only accounting for 6% of small boat arrivals in July to December 2024 (1,354 arrivals). In April 2024, the UK signed an agreement with Vietnam to increase cooperation on dealing with irregular migration and the government are continuing to work with Vietnam.
In contrast, Syrian nationals accounted for a higher proportion of small boat arrivals in the second half of the year, accounting for 14% of small boat arrivals from July to December 2024 (3,195 arrivals), compared to 11% of small boat arrivals from January to June 2024 (1,435 arrivals).
Figure 4: Top nationalities arriving on small boats, 2018 to 20241,2
Source: Irregular migration to the UK detailed dataset, year ending December 2024 - Irr_D01
Notes:
- The top 5 nationalities of small boat arrivals 2024 plus Albania. Albania has been presented to reflect that it was a nationality with a large number of small boat arrivals over recent years but is no longer a top 5 nationality.
- Excludes arrivals where information on nationality was not recorded in the dataset.
3. Asylum claims from small boat arrivals
The vast majority of small boat arrivals claim asylum, but small boat arrivals only accounted for about one-third (32%) of the total number of people claiming asylum in the UK in 2024.
Since 2018, 95% of the people arriving on a small boat have claimed asylum. Of the 139,843 small boat arrivals claiming asylum since 2018, just over half (55% or 77,191) had received a substantive decision (as of 24 January 2025, when the data used in this release was taken). Of these, 51,600 had been granted asylum or some other protection status, and 25,591 were refused.
A further 18,962 people had their claims withdrawn before an initial decision (either by the claimant, or by the Home Office). Such claims are not included in grant rate calculations as they are not substantive decisions on the claim itself.
The number of small boat arrivals with an initial decision on their asylum claim will change as more individuals have their claims processed. Cases where the person claiming asylum arrived irregularly since 7 March 2023 previously fell under the criteria set out in the Illegal Migration Act, which meant they could not have their asylum claims considered. However, on 22 July 2024, the Home Secretary changed the law to remove the retrospective application of the Illegal Migration Act. Consequently, decision making on claims from individuals who arrived in the UK after 7 March 2023 has resumed.
Table 2: Small boat arrivals claiming asylum and initial decision outcomes on their claims, by arrival date, January 2018 to December 20241,2,3,4,5
| January 2018 to December 2024 (people) | January 2018 to December 2024 (cases) | |
|---|---|---|
| Small boat arrivals | 147,849 | Not applicable |
| Asylum claims | 139,843 | 126,332 |
| Awaiting a decision | 34,310 | 30,532 |
| Received an initial decision (% of claims) | 77,191 (55%) |
68,777 (54%) |
| of which: | ||
| granted refugee status or other leave (grant rate) |
51,600 | 46,764 (68%) |
| refused | 25,591 | 22,013 |
| Withdrawn | 18,962 | 18,246 |
| Received an administrative outcome | 9,380 | 8,777 |
Source: Irregular migration to the UK detailed dataset, year ending December 2024 - Irr_D02 and Irr_D03
Notes:
- People includes main applicants and dependants, whereas cases include main applicants only.
- The time periods relate to the date of the small boat arrival, not the date of the asylum claim or outcome.
- Claims granted include grants of refugee status, humanitarian protection and other forms of leave.
- Grant rate is the percentage of claims that resulted in a grant of protection or some form of leave at initial decision, excluding withdrawn claims and claims which received an administrative outcome.
- 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.
More detail on all asylum claims is available in the ‘How many people claim asylum in the UK?’ chapter and more detail on the outcomes of asylum claims is available in the ‘How many people are granted asylum in the UK?’ chapter of the Immigration system statistics quarterly release, including definitions on asylum case outcome types in the asylum and resettlement detailed datasets.
4. 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). For more information on NRM referrals, see the ‘user guide’. For statistics on all modern slavery referrals (not just those relating to people arriving on small boats), see the ‘National Referral Mechanism statistics’.
4.1 Small boat arrivals with modern slavery referrals
Eleven per cent of small boat arrivals have been referred as potential victims of modern slavery.
Of the 147,849 small boat arrivals since 2018, 16,491 people were referred to the NRM.
The number of small boat arrivals in each year with NRM referrals may increase, as time will allow more people to identify as potential victims and be referred into the NRM.
4.2 Outcomes of small boat modern slavery referrals
Individuals referred to the NRM receive decisions on 2 grounds: reasonable grounds, and conclusive grounds.
A positive reasonable grounds decision means the decision-maker believes, based on all available general and specific evidence but falling short of conclusive proof, that a person may be a victim of modern slavery.
Following a positive reasonable grounds decision, a conclusive grounds decision will be made. A positive conclusive grounds decision indicates that, on the balance of probabilities, there is sufficient information to consider the individual is a victim of modern slavery.
In 2024, 70% of reasonable grounds decisions issued were negative.
This follows amendments made to the reasonable grounds test in January 2023. For more information see the ‘National Referral Mechanism statistics’.
Of the 4,480 conclusive grounds decisions issued since 2018, just over half (53%) were negative, meaning they were not deemed to be a victim of modern slavery.
Most small boat arrivals with NRM referrals have received a reasonable grounds decision. However, just under half of those who have received a positive reasonable grounds decision have not yet received a conclusive grounds decision, as conclusive grounds decisions take considerably longer (Table 3). More recent periods naturally have a higher proportion awaiting a conclusive grounds decision, as less time has passed for a decision to be made.
Table 3: Outcomes of small boat modern slavery referrals, by arrival date, January 2018 to December 20241,2,3,4,5
| January 2018 to December 2023 | 2024 | |
|---|---|---|
| Small boat arrivals | 112,460 | 35,389 |
| Arrivals with NRM referrals | 12,869 | 3,622 |
| Reasonable grounds (RG) decisions | 11,779 | 3,443 |
| Positive (%) | 7,068 (60%) | 1,045 (30%) |
| Negative (%) | 4,711 (40%) | 2,398 (70%) |
| Awaiting RG decision | 69 | 100 |
| Conclusive grounds (CG) decisions | 4,234 | 246 |
| Positive (%) | 1,975 (47%) | 120 (49%) |
| Negative (%) | 2,259 (53%) | 126 (51%) |
| Awaiting CG decision | 2,789 | 797 |
| Referrals withdrawn / closed | 1,050 | 79 |
| Awaiting reconsideration | 16 | 2 |
Source: Irregular migration to the UK detailed dataset, year ending December 2024 - 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 claims where contact with the individual has been lost. These may be reopened if the individual makes contact in future.
- Claims 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 NRM referrals 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.
5. Returns of small boat arrivals
Between 2018 and 2024, there have been 4,995 returns of people who arrived by small boat, 3% of all small boat arrivals during this time.
For further information on returns of small boat arrivals (and all returns from the UK), see the ‘How many people are returned from the UK?’ chapter of the Immigration system statistics quarterly release.
6. About the statistics
The Irregular Migration statistics were designated as ‘Official Statistics’ from February 2022. For more information, please see section 11.5 of the Immigration system statistics user guide.
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.
All statistics in this chapter relate to 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.
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, 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 claim
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.
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 chapter. Any counts of arrivals and attempted entries may relate to multiple arrivals or attempts by the same individual, and therefore will not relate to numbers of people.
For more information on the data in this chapter, please see the ‘user guide’.
7. Data tables
Data referred to here can be found in the following tables:
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