National statistics

How many people are detained or returned?

Updated 14 November 2023

Back to ‘Immigration system statistics, year ending June 2023’ content page.

This is not the latest release. View latest release.

Data on detention relates to the year ending June 2023 and all comparisons are with the year ending June 2022 (unless indicated otherwise).

Data on returns relates to the year ending March 2023, which is 3 months before the reporting on detention and other immigration system data. This is to allow more time for returns to be recorded on the system and ensure the published figures are an accurate representation of the number of returns. We are currently reviewing this approach for future releases. See the user guide for more details.

The Illegal Migration Bill received Royal Assent and became the Illegal Migration Act on 20 July 2023, so any effect from the new legislation will not apply to the period covered in this release.

1. Immigration detention

An individual may be detained under immigration powers under certain circumstances. This includes whilst their identity is being established, where there is a risk of absconding, or in support of the return of an individual with no legal right to be in the UK. Where an individual is being detained in support of a return, detention may continue lawfully only for as long as there is a realistic prospect of removal.

1.1 People entering immigration detention

20,354 people entered immigration detention in the year ending June 2023, 16% fewer than in the year ending June 2022.

During 2021 and 2022, a high proportion of those entering detention were small boat arrivals, detained to confirm their identity and register their asylum claim. However, in 2023, immigration removal centres have rarely been used to process small boat arrivals. This is in part due to the establishment of Manston to enable quicker routing and triage of small boat arrivals. This has allowed more individuals to move directly to community-based accommodation rather than be held in immigration detention, following initial examination and checks. The majority of Manston is a non-residential holding room where the majority of arrivals will stay for up to 24 hours. The site also has residential holding rooms in which individuals may be detained for up to 96 hours.

See the user guide for more information on the detention of small boat arrivals.

Figure 1: People entering immigration detention in the UK, year ending June 2013 to year ending June 2023

Source: Immigration detention - Det_D01

Figure 1 shows there was a general downward trend in the number of people entering detention from the peak of around 32,400 people in 2015 to around 24,500 in 2019. Since 2019, the total entering detention reached a low of around 13,000 in the year ending March 2021 following the COVID-19 pandemic, before increasing again to a recent high of around 25,500 in the year ending March 2022.

The top nationalities entering immigration detention since 2021 are similar to the top nationalities of irregular arrivals to the UK via small boats. This emphasises the role immigration detention has played in managing these new arrivals. Other notable nationalities entering detention are Indians, Romanians, Brazilians, and Poles, who are more likely to have entered immigration detention for other reasons, such as overstaying a visa or following a criminal conviction.

Albanians were the most common nationality entering detention in the year ending June 2023. They accounted for 35% of the total entering detention, or 7,064 entrants, 31% more than in the year ending June 2022. Albanians entering detention in the year ending June 2023 will have included small boat arrivals, particularly from July to September 2022, and Foreign National Offenders, as mentioned in section 2.2 below.

Afghans entering detention increased by 17% in the year ending June 2023 compared with the year ending June 2022, from 958 to 1,125. This will have been influenced by the increase in Afghans arriving via small boat in July to December 2022.

1.2 People in immigration detention

At the end of June 2023, there were 1,924 people held in immigration detention (including those detained under immigration powers in prison), as shown in Figure 2. This was 6% lower than at the end of June 2022.

Figure 2: People detained under immigration powers in the UK, by place of detention, as at the last day of the quarter, 31 March 2018 to 30 June 2023^1,2

Source: Immigration detention - Det_D02

Notes:

1. The ‘detention estate’ comprises Immigration Removal Centres (IRC), Short-Term Holding Facilities (STHF) and Pre-departure Accommodation (PDA). It is separate to those who are detained under Immigration powers in prisons – these are shown separately on the chart.
2. Data for 31 December 2022, 31 March 2023, and 30 June 2023 for the detention estate is sourced from each detention centre. Data for 31 December 2022, 31 March 2023 and 30 June 2023 for prisons is sourced from His Majesty’s Probation and Prisons Service (HMPPS). See the user guide for more information.

The number of people in detention decreased immediately during the COVID-19 pandemic. At 31 December 2019 there were 1,637 people in detention, which decreased to a low of 698 at 30 June 2020.

The number of people detained in the detention estate followed a similar trend to the total in detention, with 1,670 people detained in the detention estate at 30 June 2023.

The number of people detained in prisons under immigration powers increased, from 359 before the COVID-19 pandemic (at 31 December 2019) to 665 at 31 December 2021. This increase over the pandemic is likely to have been due to difficulties in securing returns due to the global travel restrictions and challenges around releasing some foreign national offenders (FNOs) into the community. Numbers have since decreased, with 254 people detained in prisons under immigration powers at 30 June 2023.

The number of people in detention relates to a specific point in time and is subject to daily fluctuations. For example, if a large number of people entered detention just before the end of the period, the number of people in detention would be higher than if the same people entered a few days later.

1.3 People leaving immigration detention

Figure 3 shows that more than one-third (38%) of people who left detention in the year ending June 2023 had been detained for 7 days or less, similar to the proportion prior to the COVID-19 pandemic. The years ending June 2021 and June 2022 had seen higher proportions leaving detention within 7 days, 69% and 66% respectively. This was partly due to small boat arrivals being detained for short periods on arrival, but as initial processing of small boat arrivals now mostly happens at Manston, this is no longer the case.

Figure 3: People leaving immigration detention, by length of detention^1,2, year ending June 2019 to year ending June 2023

Source: Immigration detention - Det_D03

Notes:

1. < means ‘less than’.
2. The legend follows the same order and orientation as the stacks within the bars.

People’s length of detention is often partly related to their reason for leaving detention.

The proportion of people who left detention because they were bailed has remained high (75% of those leaving detention in the year ending June 2023). Bail was mostly granted due to an asylum (or other) application being raised. However, people leaving detention were detained for longer periods in the year ending June 2023 than in the year ending June 2022. 40% of people bailed in the year ending June 2023 spent 7 days or less in detention and 31% spent 8 to 28 days in detention, compared to 71% and 13% respectively in the year ending June 2022.

More than one-fifth (22%, 4,502) of detainees leaving detention were returned overseas in the year ending June 2023, compared to less than one in six (15%, 3,470) in the year ending June 2022. However, this figure was lower compared to earlier in the preceding decade, for example in 2010 the equivalent statistic was 64% (16,577).

Figure 4: Top 10 nationalities leaving detention by reason for leaving^1,2,3, year ending June 2023

Source: Immigration detention - Det_D03

Notes:

1. Bailed Secretary of State (SoS) and Immigration Judge (IJ).
2. Other reasons for leaving detention include being sectioned under the Mental Health Act, entering criminal detention, being granted leave to enter or remain in the UK, being detained in error and people whose reason for leaving was not available at the time of publication. See the user guide for more details.
3. The legend follows the same order and orientation as the stacks within the bars.

Figure 4 shows that among the top 10 nationalities leaving detention in the year ending June 2023, in most cases the individual was bailed. However, for Brazilians (fourth) and Romanians (fifth) the majority were returned, with a notable number of Albanians (1,061) and percentage of Poles (45%) also returned. Being returned is the more common outcome for individuals detained for criminality or overstaying.

Further information on Returns is contained in the next section below.

2. Returns

The Home Office seeks to return people who do not have a legal right to stay in the UK. The different types of returns are grouped into 3 broad categories:

• enforced returns (people subject to administrative removal or deportation action which is carried out by the Home Office)
• voluntary returns (people who were liable to removal action or subject to immigration control but have left of their own accord, sometimes with support from the Home Office)
• port returns (people who are refused entry to the UK and have subsequently departed)

Figure 5: Returns from the UK, by type of return, year ending March 2014 to year ending March 2023

Source: Returns - Ret_D01

2.1 Returns by return type

2.1.1 Enforced returns

In the year ending March 2023, there were 4,193 enforced returns, an increase of 29% on the year ending March 2022 (3,257). The majority (72%) of enforced returns in the year ending March 2023 were Foreign National Offenders (FNOs) and around half (46%) of enforced returns were EU nationals.

The proportion of enforced returns that are FNOs has been decreasing steadily since 2020 during the COVID-19 pandemic, when the vast majority (99%) of enforced returns were of FNOs. In the year ending March 2023, FNO’s accounted for 72% of enforced returns and is similar to the proportion seen before the COVID-19 pandemic.

Enforced returns have been increasing steadily over the last 2 years, with the total for the year ending March 2023 being 71% higher than for the year ending March 2021. Enforced return numbers were one-third higher in January to March of 2023 than the same period in 2022. Despite these large increases, enforced returns are low by historic standards, being less than two-thirds of what they were in the year ending March 2020, just prior to the COVID-19 pandemic.

More recent provisional data has been published in the ad hoc report of Statistics relating to the Illegal Migration Act. This provisional data shows that enforced returns in 2023 have continued to increase.

The top 3 nationalities accounted for over half of all enforced returns in the year ending March 2023. These were Albania (25%), Romania (18%) and Brazil (11%). Enforced returns have increased for most nationalities compared with the previous year, with Albania and Brazil leading the recent increase in non-EU enforced returns which are now slightly higher than EU enforced returns, as shown in Figure 6 below.

The vast majority of enforced returns occurred from detention. As reported in the Home Office research ‘Issues raised by people facing return in immigration detention’ (2021), 73% of people detained within the UK following immigration offences in 2019 were recorded as having raised one or more ‘issues’ that may have prevented their return. These issues included raising an asylum claim, legal challenge, or a claim to be a potential victim of modern slavery or human trafficking.

Figure 6: Enforced returns from the UK, for EU and non-EU nationals, year ending March 2014 to year ending March 2023

Source: Returns - Ret_D01

2.1.2 Voluntary returns

In the year ending March 2023 there were 12,557 voluntary returns. This continues the recent increasing trend following the COVID-19 pandemic and represents an increase of 42% compared with the year ending March 2022. However, set against the longer-term trend, voluntary returns have decreased by 58% from the recent high in 2015 when there were over 30,000 voluntary returns.

All voluntary return types – assisted, controlled and other verified returns (further information can be found in the Returns section of the user guide) have increased in the year ending March 2023 compared with the previous year. The nationalities leading the upward trend over the year ending March 2023 were Indians, Albanians, Chinese and Brazilians.

2.1.3 Port returns

There were 24,070 passengers who were refused entry at port and subsequently departed (‘port returns’) in the year ending March 2023. This represents the highest number of port returns in over 10 years.

The nationality make-up of port returns has changed. Prior to leaving the EU, port returns of EU nationals in 2020 accounted for only 17% of all port returns. However, in the year ending March 2023 they accounted for 60%.

2.2 Returns of foreign national offenders (FNOs)

In the year ending March 2023, there were 3,141 Foreign National Offenders (FNOs) returned from the UK, of which a majority (58%, or 1,815) were EU nationals. This proportion is lower than the 69% in 2019, reflecting the increase in returns of non-EU FNOs, including Albanians, while FNO returns of EU nationals have remained low following the pandemic.

Figure 7: Returns of FNOs¹ from the UK, for EU and non-EU nationals, year ending March 2014 to year ending March 2023

Source: Returns - Ret_D03

Notes:

1. An FNO is someone who is not a British citizen and is, or was, convicted in the UK of any criminal offence, or convicted abroad for a serious criminal offence.

The vast majority (96%) of FNO returns are enforced returns, and this proportion has been fairly stationary for the last 5 years.

Figure 7 shows returns of FNOs decreased between 2017 and 2020, with the onset of the COVID-19 pandemic intensifying this trend. Since then, returns of FNOs have been gradually increasing, though are fewer by 51% compared with the recent high of around 6,400 in 2016.

In the year ending March 2023, Europeans comprised 9 out of the top 10 nationalities for returns of FNOs.

2.3 Asylum related returns

The method for classifying asylum-related returns has changed due to the automation of certain clerical processes, which has resulted in more returns being classified as asylum-related. For example, the change means asylum-related returns in the year ending June 2022 increased from 811 to 2,207 – an increase of 172%. Data back to 1 October 2020 has been revised using the new methodology. Asylum-related returns that occurred before this period have not been revised so comparisons should not be made between the numbers of asylum-related returns that occurred before and after 1 October 2020. Please see section 3.2 for more information.

Asylum related returns accounted for 8% of total returns in the year ending March 2023, up from 6% in the year ending March 2022.

In the year ending March 2023, there were 3,354 asylum related returns. This is a 68% increase compared with the year ending March 2022 (2,000), in part due to a 122% increase (from 573 to 1,272) in returns of Albanians who had claimed asylum.

3. 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. Ongoing data quality checks do not at present suggest any large effects from these changes will be apparent. For more information on this please see the user guide.

3.1 Immigration detention

The statistics in this section show the number of entries into, and departures from, detention for those held solely under immigration powers. One individual may enter or leave detention multiple times in a given period and will therefore have been counted multiple times in the statistics. Statistics on foreign nationals held in prison for criminal offences are published by the Ministry of Justice in ‘Offender management statistics quarterly’.

The detention estate comprises immigration removal centres (IRC), short-term holding facilities (STHF) and pre-departure accommodation (PDA).

The data excludes those held under immigration powers in HM prisons (prior to July 2017), police cells, short-term holding rooms at ports and airports (including Manston immigration processing centre), and those recorded as detained under both criminal and immigration powers and their dependants.

‘In detention’ data for the number of people in the detention estate as at 31 December 2022, 31 March 2023, and 30 June 2023 has been sourced from each detention centre’s daily population lists. ‘In detention’ data for the number of people in prisons for 31 December 2022, 31 March 2023, and 30 June 2023 has been sourced from His Majesty’s Probation and Prisons Service (HMPPS) list of immigration detainees. For more information, please see the user guide.

Data on those entering detention, by place of detention, relates to the place of initial detention. An individual who moves from one part of the detention estate or HM prisons to another will not have been counted as entering any subsequent place of detention. The data, therefore, does not show the total number of people who entered each part of the detention estate or HM prisons.

Data on those in detention relates to those in detention on the last day of the quarter and are therefore subject to daily fluctuations and can depend on how many people entered detention just before the end of the period.

Data on those leaving detention, by place of detention, relates to the place of detention immediately prior to being released. An individual who moves from one part of the detention estate or HM prisons to another has not been counted as leaving each part of the detention estate or HM prisons. The data, therefore, does not show the total number of people who left each part of the detention estate or HM prisons.

From July 2017, data on detention of immigration detainees in prisons is included in the immigration detention figures upon entering immigration detention within prison. Therefore, data from July 2017 onwards is not directly comparable with earlier data. Further details of these changes can be found in the user guide.

Data on the number of children entering detention is subject to change. This will be as a result of further evidence of an individual’s age coming to light, such as an age assessment. Further details can be found in the user guide.

Data on deaths in detention includes any death of an individual while detained under immigration powers in an IRC, STHF, PDA, under escort, or after leaving detention if the death was as a result of an incident occurring while detained or where there is some credible information that the death might have resulted from their period of detention and the Home Office has been informed. The annual data for 2022 is included in table Det_05b in the Detention summary tables. Further details can be found in the user guide.

3.2 Returns

Data on returns is published a quarter behind other immigration system statistics to allow more time for returns (particularly ‘other verified returns’) to be entered on the system prior to publication, ensuring that the published data is an accurate representation of the number of returns. We routinely revise the latest 8 quarters of data as part of each quarterly release. Therefore, data for the most recent 8 quarters should be considered provisional. Further details on the revisions can be found in the returns section of the user guide.

The statistics in this section show the number of returns from the UK. One individual may have been returned more than once in a given period and, if that was the case, would be counted more than once in the statistics.

The Home Office seeks to return people who do not have a legal right to stay in the UK. This includes people who:

• enter, or attempt to enter, the UK illegally (including people entering irregularly and by means of deception on entry)
• are subject to deportation action; for example, due to a serious criminal conviction
• overstay their period of legal right to remain in the UK
• breach their conditions of leave
• have been refused asylum

The term ‘deportations’ refers to a legally defined subset of returns, which are enforced either following a criminal conviction, or when it is judged that a person’s removal from the UK is beneficial to the public good. The published statistics refer to enforced returns which include deportations, as well as cases where a person has breached UK immigration laws, and those removed under other administrative and illegal entry powers that have declined to leave voluntarily. Figures on deportations, which are a subset of enforced returns, are not separately available.

Data on voluntary returns is subject to upward revision, so comparisons over time should be made with caution. In some cases, individuals who have been told to leave the UK will not notify the Home Office of their departure from the UK. In such cases, it can take some time for the Home Office to become aware of such a departure and update the system. As a result, data for more recent periods will initially undercount the total number of returns. ‘Other verified returns’ are particularly affected by this.

Improved linking between return and asylum case working systems means asylum-related returns are recorded more accurately. Changes to the way asylum-related returns are classified have been made from 23 February 2023 with data from 1 October 2020 onwards having been revised. Data before 1 October 2020 has not been revised so comparisons cannot be made for returns before and after this period. More information on this change is given in the user guide.

Asylum-related returns relate to cases where there has been an asylum claim or further submission at some stage prior to the return. This will include asylum seekers whose asylum claims have been withdrawn, refused and who have exhausted any rights of appeal, those returned under third-country provisions, as well as those granted asylum/protection but removed for other reasons (such as criminality).

Information on harm assessment categories (previously published in table Ret_06 in the accompanying Returns summary data tables) have been discontinued from the May 2023 publication onwards due to changes in the availability of this data. The latest data is available up to the year ending September 2022.

In the Immigration detention tables, the number of people ‘returned’ under ‘reason for leaving detention’ includes people who were refused entry at port in the UK who were subsequently detained and then departed the UK. However, in the ‘Returns’ tables, the number of returns from detention do not include those people, and so will be lower.

Prior to the UK leaving the EU, certain individuals applying for international protection (asylum) could be returned from the UK to the relevant EU member state that was deemed responsible for examining the application, under the Dublin Regulation. Data on returns, and requests for transfer out of the UK under the Dublin Regulation, by article and country of transfer, is available from the Asylum data tables. Strengthened inadmissibility rules came into effect on 1 January 2021, following the UK’s departure from the EU. Data on cases dealt with under the inadmissibility rules, since January 2021, can be found in the ‘How many people do we grant protection to?’ section. Further details on the Dublin Regulation and inadmissibility rules are set out in the user guide.

Prior to the UK leaving the EU, nationals from the EU could be returned for abusing or not exercising Treaty rights or deported on public policy grounds (such as criminality).

Eurostat publishes a range of enforcement data from EU member states. This data can be used to make international comparisons.

3.3 Windrush Scheme

The Windrush generation refers to people from Caribbean countries who were invited by the British government between 1948 and 1971 to migrate to the UK as it faced a labour shortage due to the destruction caused by World War 2. Not all of these migrants have documentation confirming their immigration status and, therefore, some may have been dealt with under immigration powers.

Data relating to the Windrush compensation scheme is published as part of the Home Office Transparency data.

4. Data tables

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

• Immigration detention summary tables
• Detailed immigration detention datasets
• Returns summary tables
• Detailed returns datasets

We welcome your feedback

If you have any comments or suggestions for the development of this report, please provide feedback by emailing MigrationStatsEnquiries@homeoffice.gov.uk. Please include the words ‘PUBLICATION FEEDBACK’ in the subject of your email.

We’re always looking to improve the accessibility of our documents. If you find any problems or have any feedback relating to accessibility, please email us.

See section 6 of the ‘About this release’ section for more details.