National statistics

How many people are detained or returned?

Published 29 February 2024

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

Data on detention and returns relates to 2023 and all comparisons are with 2022 (unless indicated otherwise).

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

15,864 people entered immigration detention in 2023, 24% fewer than in 2022. This continues a long-term downward trend since 2015.

Figure 1: People entering immigration detention in the UK, 2014 to 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 2019. The decrease over that period will be linked to the Government’s response to the 2016 Stephen Shaw review of detention, wherein the use of immigration detention was reduced and alternatives to detention were sought. The number detained fell further during the COVID-19 pandemic, returning to pre-pandemic levels at the end of 2021 but has fallen since.

Between 2021 and 2023, the number of people entering detention fell by around a third (36%) to 15,864. 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, one-third of the total in 2023.

Albanians were by far the largest nationality entering detention accounting for over a third (5,324 or 34%) of entries with the next largest nationality being Indians comprising 10% (1,542).

1.2 People in immigration detention

As at 31 December 2023, there were 1,782 people held in immigration detention.

The number of people in Immigration detention was 54% higher on 31 December 2023 than it was on 31 December 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 2019 to 31 December 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 has since returned to levels seen just prior to the pandemic.

The vast majority of people are detained in the Immigration detention estate, rather than prisons (1,676 out of 1,782 people at the end of December 2023). The number of people detained in prisons under immigration powers has been falling since 31 December 2021, and there were 106 people detained in prisons under immigration powers on 31 December 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 reporting 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

One fifth (19%) of people who left detention in 2023 had been detained for 7 days or less, the lowest proportion since the time series began in 2010. 42% of people were detained between 8 and 28 days.

Figure 3 shows that the proportion staying in detention for 7 days or less was much lower in 2023 than it was in 2021 (76%). This was likely due to high numbers of small boat arrivals that year, which were still being initially detained for short periods on arrival within the detention estate.

The proportion leaving within 7 days is also low compared to years before small boat arrivals started being recorded, when detention was more commonly used to prepare people for return.

Figure 3: People leaving immigration detention, by length of detention^1,2, 2019 to 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 2023 was bail (61%).

Bail is often granted for cases considered at low risk of absconding or criminality, who are awaiting the outcome of an asylum application or are waiting for arrangements to be made for their removal.

The proportion of detainees leaving detention due to being bailed has fallen from 77% in 2022 to 61% in 2023. 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). It may also reflect greater numbers of returns from detention in 2023 – see the Returns section for more information.

The number of people leaving detention due to being returned has increased by 19% in the last year, from 4,206 to 5,021. This increase was mostly driven by returns of Albanian nationals.

Albanians were mostly behind the increase in returns from detention in 2022. Further information on the wider increase in Albanian returns can be found in the Returns section. The proportion of people being returned upon leaving detention has increased from 20% in 2022 to 33% of departures in the latest year. However, this proportion was higher historically – averaging 44% from 2015 to 2019. This longer term fall in the proportion of detainees leaving due to being removed may have been linked to increasing numbers of detainees raising issues that prevented their return, as reported in the Home Office research ‘Issues raised by people facing return in immigration detention’ (2021). This research showed that 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 4: Top 10 nationalities leaving detention by reason for leaving^1,2,3, 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 2023, in most cases the individual was bailed. However, for Romanians and Lithuanians, the majority leaving detention were returned. Being returned is the more common outcome for individuals detained for criminality (that is, foreign national offenders) which is also why we see a higher proportion for Polish nationals. There were also a substantial number of Albanians being returned on leaving detention (1,574), though this represented less than a third (31%) of total Albanians leaving detention as most were bailed.

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 December 2014 to year ending December 2023

Source: Returns - Ret_D01

2.1 Enforced returns

In 2023 there were 6,393 enforced returns, an increase of 66% on the previous year (3,855).

The increase in enforced returns this year was largely driven by Albanian returns which increased substantially from 958 in 2022 to 2,501 in 2023. This follows the signing of the agreement in December 2022 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 2023 being more than double that in 2021 (2,788), when pandemic travel restrictions made returns difficult. Despite these large increases, enforced returns were 11% below what they were in 2019 (7,198), just prior to the COVID-19 pandemic.

Over half (58%) of enforced returns in 2023 were FNOs, a similar proportion to before the COVID-19 pandemic. See section 2.4 of this chapter for more detail on FNO returns.

Albanian and Romanian nationals accounted for over half of all enforced returns in 2023, accounting for 39% and 17% respectively.

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 one-third (36%) of enforced returns were EU nationals in 2023.

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

Source: Returns - Ret_D01

2.2 Voluntary returns

Voluntary returns increased by 76% in 2023 compared to the previous year.

In 2023 there were 19,253 voluntary returns. This continues the recent increasing trend following the COVID-19 pandemic and is above pre-pandemic levels. However, voluntary returns are still 37% lower than the recent high in the year ending March 2016.

2.3 Port returns

There were 24,587 passengers who were refused entry at port and subsequently departed (‘port returns’) in 2023. This represents the highest number of port returns since 2009, when there were 29,336.

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 2023 they accounted for 61%. Half (48%) of EU port returns in 2023 were Romanians, while the next most common nationality was Bulgarian (12%). Non-visa nationals such as those from EU countries can be refused entry because they do not have the necessary immigration permission to carry out the activities they intend to undertake while they are here. Border Force take decisions to stop arriving passengers based on the information that they provide, and not on the basis of their nationality.

2.4 Returns of foreign national offenders (FNOs)

In 2023, there were 3,926 foreign national offenders (FNOs) returned from the UK, of which around half (49%, or 1,934) were EU nationals. This is the first time since 2013 that annual returns of non-EU FNOs have exceeded numbers of returns of EU FNOs, which has been due to the large numbers of returns of Albanians following the agreement reached with the Government of Albania in December 2022. Albanian nationals constituted over one-third (37%) of all FNO returns over the year.

Figure 7: Returns of FNOs¹ from the UK, for EU and non-EU nationals, 2014 to 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 41% lower than the recent peak of 6,628 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 2023, there were 6,014 asylum-related returns, twice as many as in 2022 (2,931). This is mainly due to a substantial increase (from 988 to 3,369) in Albanian asylum-related returns, following higher volumes of refused and withdrawn Albanian asylum claims in 2023.

In 2023, 23% of enforced and voluntary returns were asylum-related.

2.6 Small boat returns

1,889 returns in 2023 related to individuals who arrived via small boat.

There were 1,889 returns of small boat arrivals in 2023, representing 7% of all enforced and voluntary returns during the year. This was almost 5 times higher than the number of small boat arrivals returned in 2022 (379).

Further information about returns of small boat arrivals can be found in the ‘Irregular migration to the UK’ publication.

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 through to 31 December 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 through to 31 December 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 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.

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. 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.

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

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