Accredited official statistics

How many people are detained or returned?

Updated 7 December 2023

Back to ‘Immigration system statistics, year ending September 2023’ contents page.

This is not the latest release. View latest release.

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

Data on returns also relates to the year ending September 2023 following the cessation of a 3-month reporting lag which was applied in earlier releases. Improvements to the production process has enabled us to report the data more quickly. See the user guide for more details.

1. Immigration detention

An individual may be detained under immigration powers under certain circumstances. This includes detention in support of the return of the individual with no legal right to be in the UK. In some cases individuals may be detained whilst their identity is being established or where there is a risk of absconding.

1.1 People entering immigration detention

16,363 people entered immigration detention in the year ending September 2023, 31% fewer than in the year ending September 2022. This decrease is due in part to small boat arrivals no longer being processed initially in the detention estate.

Figure 1: People entering immigration detention in the UK, year ending September 2014 to year ending September 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 32,700 people in the year ending September 2015 to around 24,500 in the year ending September 2019. The number fell during the COVID-19 pandemic, returning to pre-pandemic levels at the end of 2021. Since then, numbers entering detention have fallen sharply, down a third to 16,363, in the latest year.

During 2021 and 2022, a high proportion of those entering detention were small boat arrivals, detained for short periods in order to confirm their identity and register their asylum claim. However, immigration detention facilities are now rarely used to process small boat arrivals, who are now processed on arrival at the Manston facility. This has allowed more individuals to move directly to community-based accommodation rather than be held in immigration detention, following the initial examination and checks.

Albanians were the most common nationality entering detention, almost one-third of the total in the year ending September 2023.

Albanians were by far the largest nationality entering detention accounting for 31% of entries (5,147) with the next largest nationality being Indians comprising 9% (1,449). However, numbers of Albanians entering detention decreased by 35% in the last year. This is due in part to high numbers of Albanian small boat arrivals last year being processed in the detention estate, compared to this year where small boat arrivals are now being processed outside of the detention estate.

1.2 People in immigration detention

As at 30 September 2023, there were 1,841 people held in immigration detention. This was 11% fewer than a year earlier.

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 September 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 onwards for the detention estate is sourced from each detention centre. Data for 31 December 2022 onwards 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 sharply at the start of the COVID-19 pandemic, but have since returned to levels seen just prior to the pandemic.

The majority of people detained are held in the detention estate, rather than prisons (1,754 out of 1,841 people at the end of September 2023). The number of people detained in prisons under immigration powers has been falling since 31 December 2021, with 87 people detained in prisons under immigration powers on 30 September 2023. Since the start of June 2023, some FNOs who have served their sentence in prison have been transferred into the detention estate if assessed as suitable and low risk.

The number of people in detention relates to a point in time but numbers will fluctuate daily. If a large number of people entered detention just before the end of the period, the number of people in detention reported in these statistics would be higher than if the same people entered a few days later.

1.3 People leaving immigration detention

Less than one quarter (23%) of people who left detention in the year ending September 2023 had been detained for 7 days or less, the lowest proportion in our time series going back to 2010. Most commonly, people were detained for 8 to 28 days (41%).

Figure 3 shows that the years ending September 2021 and September 2022 had seen higher proportions of people leaving detention within 7 days at 72% and 58% 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. It is worth noting that the proportion leaving within 7 days is also low compared to periods before small boat arrivals started being recorded, when detention was more commonly used to prepare people for return. The chart shows that the segment of detainees being held for 8 to 28 days became the largest in the latest year.

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

The most common reason for leaving detention in the year ending September 2023 was bail (68%), while 27% were returned.

Over two-thirds of people leaving detention have been bailed with most of these bailed due to an asylum application.

The number of detainees bailed represents a decrease of 39% on the previous year from 18,601 to 11,409. This drop reflects a reduction in the use of detention to process new irregular arrivals (many of whom claim asylum and would therefore leave detention on bail).

The proportion (and number) of people leaving due to being returned has increased from 18% of people leaving detention in the year ending September 2022 to 27% of departures in the latest year. This increase was mostly driven by returns of Albanian nationals. However, the proportion was substantially higher historically – averaging 44% from 2015 to 2019.

Figure 4: Top 10 nationalities leaving detention by reason for leaving^1,2,3, year ending September 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 September 2023, in most cases the individual was bailed. However, for Brazilians (third), Romanians (fourth) and Polish nationals (sixth), over one third of their number were returned, with a notable number of Albanians (1,221) also returned. Being returned is the more common outcome for individuals detained for criminality (that is, foreign national offenders).

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 September 2014 to year ending September 2023

Source: Returns - Ret_D01

2.1 Enforced returns

In the year ending September there were 5,506 enforced returns, an increase of 54% on the previous year (3,569).

Enforced return numbers were 57% higher in January to September of 2023 than the same period in 2022. Albanian returns comprise over half (58%) of this increase. This follows greater cooperation over the last year between the UK and Albanian governments to deter and disrupt illegal migration and criminal networks.

Enforced returns have been increasing steadily over the last 2 years, with the total for the year ending September 2023 being more than double that for the year ending March 2021, the recent low as seen in figure 5. Despite these large increases, enforced returns were 24% below what they were in 2019, just prior to the COVID-19 pandemic.

The majority (62%) of enforced returns in the year ending September 2023 were FNOs, a similar proportion to before the COVID-19 pandemic.

Two nationalities accounted for over half of all enforced returns in the year ending September 2023: Albania (35%) and Romania (17%).

Enforced returns have increased for most nationalities compared with the previous year. The recent increase in non-EU enforced returns was mainly due to more Albanians being returned. Around two-fifths (39%) of enforced returns were EU nationals in the year ending September 2023.

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

Source: Returns - Ret_D01

The vast majority of enforced returns occurred directly 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.

2.2 Voluntary returns

Voluntary returns increased by 74% in the year ending September 2023 compared to the previous year.

In the year ending September 2023 there were 17,301 voluntary returns. This continues the recent increasing trend following the COVID-19 pandemic and the number is now above pre-pandemic levels. However, voluntary returns are 44% lower than the recent high in the year ending March 2016.

All voluntary return types – controlled, assisted and other verified returns have increased in the latest year. While controlled and assisted returns are tracked by the Home Office as they happen, other verified returns are recorded only where it has been established immigration offenders have left or have been identified leaving the UK without formally notifying the Home Office and so their number may be incomplete. Two thirds (64%) of voluntary returns are other verified returns and were primarily Albanian, Indian and Chinese nationals.

2.3 Port returns

There were 24,620 passengers who were refused entry at port and subsequently departed (‘port returns’) in the year ending September 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 September 2023 they accounted for 60%.

2.4 Returns of foreign national offenders (FNOs)

In the year ending September 2023, there were 3,577 foreign national offenders (FNOs) returned from the UK, of which a majority (53%, or 1,886) were EU nationals. This proportion is lower than the 69% in 2019, reflecting an increase in returns of non-EU FNOs, most prominently Albanians following the agreement reached with the Government of Albania, while FNO returns of EU nationals have remained low following the pandemic. Albanian nationals constituted one-third (33%) of all FNO returns over the period.

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

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 in the latest year they are still around half the level than at the recent peak of around 6,600 FNO returns in the year ending March 2017.

2.5 Asylum-related returns

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).

In the year ending September 2023, there were 5,284 asylum-related returns. This is twice as many as in the year ending September 2022 (2,537). The year-on-year increase is mainly due to a substantial increase (from 746 to 2,749) in Albanian asylum-related returns. A large proportion of Albanian asylum claims have been withdrawn in 2022 and 2023, resulting in a large number of Albanians that would then need to be returned.

In the year ending September 2023, 22% of enforced and voluntary returns were asylum-related.

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, 30 June 2023 and 30 September 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, 30 June 2023 and 30 September 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 is 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 no longer published a quarter behind other immigration system statistics, as of the 23 November 2023 release. Improvements to the speed at which data can be extracted and collated for publication has enabled us to report the data in a more timely way, without the lag. Please see the user guide for more information.

We will continue to 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.

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.

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.