Official Statistics

Irregular migration to the UK, year ending September 2023

Published 23 November 2023

This is not the latest release. View latest release.

1. Introduction

This statistical release from the Home Office provides an overview of Irregular migrants who come to the UK. 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 become 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. Additionally, other migrants may enter irregularly but gain ‘regular’ status (for example, following an application for asylum).

The statistics presented here relate to the number of people recorded being detected on, or shortly after, arrival to the UK on various irregular routes. They do not provide an indication of the total number of people currently in the UK who have entered the UK via irregular routes, or the number of irregular migrants present in the UK. It is not possible to know the exact size of the irregular population currently resident in the UK, nor the total number of people who enter the UK irregularly.

Other migrants may seek to enter the UK without valid permission but are then 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 counted in this release. Any counts of attempted entries will relate to a number of recorded detections, which may include multiple attempts by the same individual, and therefore will not relate to numbers of persons.

Additional information is provided in the ‘About the statistics’ section, including notes on data quality.

2. Irregular arrivals

These statistics do not provide a full picture of how many people entered the UK without permission. Not all arrivals will be recorded under each of the presented methods of entry and coverage 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 September 2023, there were 45,081 detected irregular arrivals to the UK, down 16% from the year ending September 2022, 83% of these arrived via small boats. In July to September 2023, detected irregular arrivals were 33% lower than in July to September 2022.

As shown in Figure 1, small boats have been the predominant recorded method of entry for irregular arrivals since 2020, when entries via this route increased rapidly and detections on other routes declined (likely in part due to the COVID-19 pandemic making other methods of entry such as air or ferry less viable). Small boats continue to be the predominant recorded method, despite the other entry methods having become more viable again as global COVID-19 restrictions have eased. Small boat arrivals are also the most visible of the irregular routes, so the most likely to be detected.

Small boat arrival numbers are subject to seasonal fluctuations during the year due to weather effects, with typical peaks in the warmer summer months (Q3, July to September), as can be seen in Figure 1. Comparisons of arrivals between the same months in different years may likewise be affected by differences in weather conditions.

Figure 1: Detections at the UK border, by method of entry, January 2018 to September 2023

Source: Irregular migration to the UK - Irr_D01

3. How many migrants were detected arriving in the UK via 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 persons 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 ‘About the statistics’ section for more details).

In the year ending September 2023 there were 37,556 people detected arriving by small boats, 16% fewer than in the year ending September 2022 when there were 44,490. There were fewer arrivals in 8 of the 12 months in the year ending September 2023 compared with the year ending September 2022, as shown in Figure 2. October 2023 (as published in the latest Statistics relating to the Illegal Migration Act) also had fewer small boat arrivals than October 2022.

Small boat arrivals from July to September 2023 were 34% lower than in the same 3 months of 2022. This decrease is largely due to a reduction in Albanians arriving in the year ending September 2023 (further detail in Section 3.3 below). The number of small boat arrivals from other nationalities increased 9% over the year as a whole (from 32,466 arrivals in the year ending September 2022 to 35,508 arrivals in year ending September 2023).

Figure 2: Number of people detected arriving in the UK via small boats per month, January 2021 to September 2023

Source: Irregular migration to the UK summary tables - Irr_02a

3.2. Number of boats and people per boat

In the year ending September 2023 there were 787 boats detected arriving to the UK, just over a third (34%) fewer than the 1,189 in the year ending September 2022. Although the number of people and boats arriving have dropped, the number of people per boat continues to increase.

Figure 3: Number of small boats and average number of people per boat detected arriving to the UK, January 2018 to September 2023

Source: Irregular migration to the UK summary tables - Irr_02a

In the year ending September 2023, there was an average of 48 people per small boat. This was higher than the year ending September 2022, when there was an average of 37 people per small boat and as Figure 3 shows it is much higher than earlier years - in 2020 (13 people per small boat), 2019 (11 people) and 2018 (7 people).

In the year ending September 2023, there was at least one small boat recorded arriving on 2 out of every 5 days (an arrival on 152 of the 365 days). This was a slightly lower rate compared with the year ending September 2022 (167 of the 365 days) but higher than the rate of just over a third of days in 2020 (130 of the 366 days).

3.3 Nationalities and demographics of arrivals

Overall, males represented 88% of small boat arrivals in the year ending September 2023. This is a similar proportion as each year from 2018 to 2021. Since January 2018, 75% of small boat arrivals have been adult males aged 18 and over. Around one-sixth (17%) of small boat arrivals have been children aged 17 and under (see table Irr_02c).

In the year ending September 2023, a quarter of small boat arrivals were Afghans (8,994) and over the last 2 years (October 2021 to September 2023) Afghans were the most common nationality amongst small boat arrivals, as shown in Figure 4.

Albanians made up a substantial proportion of small boat arrivals in July to September (Q3) 2022. However, since then the number of Albanian small boat arrivals has declined, with 2,048 arrivals in the year ending September 2023, compared to 12,024 arrivals in the year ending September 2022 (an 83% decrease).

Iranians have been the most commonly detected nationality over the last 5 years, since January 2018, making up 19% of all small boat arrivals. Whilst they were no longer the top nationality in the year ending September 2023, as they were in 2018 to 2021, they were the second highest detected nationality. Iraqi and Syrian nationals have also regularly been detected arriving by small boat and they ranked third and sixth respectively for the year ending September 2023.

Other notable nationalities arriving by small boat in the year ending September 2023 are Turkish (2,909) and Eritrean (2,890) nationals, who ranked fourth and fifth respectively for the year and accounted for 8% of small boat arrivals each. However, they were the second and third most common nationalities in the latest 6 months (April to September 2023). Arrivals of Turkish nationals were almost 4 times higher compared to the year ending September 2022 (749).

The nationalities mentioned above (with the exception of Albanians), remain in the top 6 nationalities arriving via small boat in October 2023 (see the latest Statistics relating to the Illegal Migration Act for October 2023 figures).

Figure 4: Top nationalities arriving via small boats, October 2021 to September 2023^1,2,3

Source: Irregular migration to the UK - Irr_D01

Notes:

1. The top nationalities are those with the highest number of small boat arrivals since October 2021.
2. Excludes arrivals where information on nationality was not recorded in the dataset.
3. The legend follows the same order and orientation as the stacks within the bars.

4. Asylum claims from small boat arrivals

Due to the transition to a new data system, data for asylum claims from small boat arrivals for June to September 2023 was unavailable at the time of publication. Further updates will be included in future editions of this publication once available.

Data for asylum claims from small boat arrivals in June 2023 was not available. Therefore, data for the ‘year ending June 2023’ covers July 2022 to May 2023.

The majority of small boat arrivals claim asylum. In the year ending June 2023, 90% (36,169 of 40,386 arrivals) had an asylum claim recorded either as a main applicant or dependant, at the time of data extraction. Small boat arrivals accounted for over one-third (37%) of the total number of people claiming asylum in the UK in the year ending June 2023.

Seventy four per cent of all small boat asylum applications since 2018 were still awaiting a decision as of June 2023. 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. Of those small boat arrivals who had received an initial decision (12,979) since 2018, 65% (8,399) were granted refugee status or another type of leave.

More detail on asylum claims from small boat arrivals is available in section 4 of the ‘Irregular migration to the UK, year ending June 2023’ release.

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

Due to the transition to a new data system, data for small boat arrivals with National Referral Mechanism (NRM) referrals from June to September 2023 was unavailable at the time of publication. Further updates will be included in future editions of this publication once available.

Data for small boat arrivals with NRM referrals in June 2023 was not available. Therefore, data for the ‘year ending June 2023’ covers July 2022 to May 2023.

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 has been increasing. For more information on NRM referrals, see the ‘About the statistics’ section.

5.1 Small boat arrivals with modern slavery referrals

A small proportion of small boat arrivals are referred to the NRM as potential victims of modern slavery. Of the 91,918 people that arrived in the UK on small boats between 1 January 2018 and 30 June 2023, fewer than one in 10 (9% or 7,923 people) had been referred to the NRM. Most of these individuals (7,466 or 94%) also had an asylum claim lodged.

The number of small boat arrivals in each year with NRM referrals is likely to increase over time, particularly for more recent years, as people have more time to be identified (or identify) as a potential victim and be referred into the NRM.

5.2 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 objective factors but falling short of conclusive proof, that a person may be a victim of modern slavery (human trafficking or slavery, servitude, or forced or compulsory labour).

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.

Most small boat arrivals with NRM referrals have received a reasonable grounds decision, but not yet received a conclusive grounds decision. 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.

The majority (78%) of reasonable grounds decisions for small boat arrivals since 2018 have been positive. Of the 780 conclusive grounds decisions issued, 78% were positive.

More detail on small boat arrivals with NRM referrals is available in section 5 of the ‘Irregular migration to the UK, year ending June 2023’ release.

6. 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 irregular migrants will successfully evade border controls and remain in the UK undetected
• some migrants who enter the UK regularly may subsequently become ‘irregular’ migrants – for example, if they overstay a visa (it should be noted that there are a number of ways in which a migrant’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 on the same route or across different routes (such individuals will be counted multiple times in the statistics)
• some migrants who enter the UK irregularly may subsequently become ‘regular’ migrants – 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 includes the number of people recorded as attempting to enter the UK, having been detected on, or within 72 hours of arrival to the UK. It 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).

6.1 Small boats

A ‘small boat’ is one of a number of vessels used by individuals who cross the English Channel, with the aim of gaining entry to the UK without a visa or permission to enter – either directly by landing in the UK or having been intercepted at sea by the authorities and brought ashore. The most common small vessels detected making these types of crossings are rigid-hulled inflatable boats (RHIBs), dinghies and kayaks.

The statistics in this release include individuals who:

• are detected on arrival to the UK
• are detected in the Channel by UK authorities and subsequently brought to the UK

These statistics do not include individuals who:

• arrive on larger vessels, such as go-fast craft, yachts, motor cruisers, tugs and fishing vessels – although these are rarely used by irregular migrants at present
• arrive in the UK irregularly on larger vessels not referenced above, including where hidden in a vehicle on a ferry
• are prevented from departing France, or those intercepted by French authorities and returned to France
• arrive in the UK undetected, or where there have been reports of people making the crossing, but no actual encounters

In some instances, particularly during periods of high numbers of arrivals, it can take some time for the full information from an asylum claim to be checked and recorded on case working systems. Data on the total number of small boat arrivals (from 2021 onwards) is derived from manual records collated by Border Force officers. More detailed breakdowns (for example, nationality, sex and age) are derived from case working systems, including the asylum application, which take longer to complete. As a result, data for some periods, particularly more recent periods, may have a number of cases where a full breakdown is not yet available.

The Home Office publishes provisional daily and weekly numbers since 1 January 2018 on ‘Migrants detected crossing the English Channel in small boats’. Figures in this release may differ from the provisional daily figures due to more time available for additional information to be recorded and additional quality assurance to be undertaken.

6.2 Modern slavery referrals – National Referral Mechanism (NRM)

When referred to the NRM, the Home Office makes a ‘reasonable grounds’ decision on whether an individual could be a victim of modern slavery.

Reasonable grounds decisions are those taken by the competent authorities to determine if there are reasonable grounds to believe, based on objective factors but falling short of conclusive proof, that a person is a victim of modern slavery (human trafficking or slavery, servitude, or forced or compulsory labour).

Adults given a positive reasonable grounds decision can have access to support if they need it. In England and Wales this support includes accommodation, financial support and other material assistance, legal aid and medical treatment while pending a conclusive grounds decision on their case. Local authorities support children.

Conclusive grounds decisions are those taken following a positive reasonable grounds decision by the competent authorities as to whether, on the balance of probabilities, there are sufficient grounds to decide that the individual being considered is a victim of modern slavery.

Adults in NRM support in England and Wales who receive a positive conclusive grounds decision receive a minimum of 45 days of ‘move-on’ support. After this they can continue to receive support on a needs-basis until they exit through the Recovery Needs Assessment process. Those with a negative decision receive 9 days of ‘move on’ support as the individual exits NRM support.

The Devolved Administrations in Scotland and Northern Ireland provide support to victims. In Northern Ireland individuals will receive support for at least 45 days while their case is considered. In Scotland, individuals will receive support for 90 days or until a conclusive grounds decision is made, whichever comes sooner. However, in some cases support may be offered beyond the 90 days if a conclusive grounds decision has not yet been made.

For further information, see the National Referral Mechanism statistics collection.

The number of small boat arrivals in each year with NRM referrals is likely to increase over time, particularly for more recent years, as people have more time to be identified (or identify) as a potential victim and be referred into the NRM.

The time periods between National Referral Mechanism statistics collection and these statistics do not align. These statistics relate to the date of arrival into the UK whereas the NRM statistics are based on date of referral into the NRM or date of decision.

6.3 Other entry methods

This report also refers to some other modes of irregular entry: in country detections; UK port detections; and inadequately documented air arrivals. Data in these sections is derived from Home Office Management Information. The data is not designed for statistical purposes and should therefore be interpreted with caution.

Each dataset will be subject to a number of unknowns, for example, an unknown number of people will evade detection altogether. Additionally, there will be instances where a detection may not be recorded on the system. The extent of these will vary between datasets and as such, it is not advisable to compare different datasets, or possible to infer the total number of people attempting to enter irregularly on each route.

Data on inadequately documented air arrivals relates to individuals who intentionally attempt to arrive in the UK via air routes either without adequate documentation or using fraudulent documentation. It does not include passengers who have genuinely made a mistake, lost their documents, or have arrived inadequately documented for reasons outside of their control. It does not include those who were prevented from boarding at their port of embarkation.

Data on recorded detections in the UK relates to detections of individuals outside of the controlled environment of a port, who when encountered are believed by authorities to have evaded border controls to enter the UK irregularly, up to 72 hours before being detected. It includes detections at the ports serviced by the juxtaposed controls (Dover, Cheriton/Longport and St Pancras).

Data on recorded detections at UK ports includes individuals attempting to enter the UK irregularly at ports. It includes, for example, those detected at ports in lorries, and shipping containers. It does not include detections at ports that are serviced by the juxtaposed controls or those prevented from leaving their port of embarkation en route to the UK, such as those detected at the juxtaposed controls.

7. Data tables

Data referred to here can be found in the following tables:

• Irregular migration summary tables
• Detailed irregular migration datasets