Accredited official statistics

How many people are detained or returned?

Updated 13 June 2024

Back to ‘Immigration system statistics, year ending March 2024’ contents page.

This is not the latest release. View latest release.

Data on detention and returns relates to the year ending March 2024 and all comparisons are with the year ending March 2023 (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

16,031 people entered immigration detention in the year ending March 2024. This is 23% fewer than in the year ending March 2023 and continues the long-term downward trend since 2015.

Figure 1: People entering immigration detention in the UK, year ending March 2015 to the year ending March 2024

Source: Immigration detention - Det_D01

Figure 1 shows the number of people entering detention reducing from a peak of around 32,700 people in the year ending September 2015 to around 24,500 in 2019. The decrease over that period could 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, only returning to pre-pandemic levels at the end of 2021 but has fallen since by more than one third (35%) to around 16,000 in the year ending March 2024.

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 for small boat arrivals, who are instead 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, just over one-third of the total in the year ending March 2024.

Albanians were the largest nationality entering detention, accounting for just over one-third (5,708 or 36%) of entries. This probably reflects the large numbers of Albanians with no right to remain who are being removed via detention. The next largest nationality are Indians comprising 9% (1,445).

1.2 People in immigration detention

As at 31 March 2024, there were 1,913 people held in immigration detention.

The number of people in immigration detention was 20% higher on 31 March 2024 than on 31 March 2023.

Figure 2: People detained under immigration powers in the UK, by place of detention, as at the last day of the quarter, 30 June 2019 to 31 March 2024^1,2

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 (1,808 out of 1,913 people at the end of March 2024), rather than prisons. The number of people detained in prisons under immigration powers fell between the end of 2021 and 30 September 2023 since when it has remained around 100. At 31 March 2024 there were 105 people detained in prisons under immigration powers, compared with 621 at 31 March 2022. Since the start of June 2023, some foreign national offenders (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

Less than one-fifth (17%) of people who left detention in the year ending March 2024 had been detained for 7 days or less, the lowest proportion since the time series began in 2010.

Figure 3 shows that the proportion staying in detention for 7 days or less was much lower in the year ending March 2024 than it was 3 years earlier in the year ending March 2021 (64%). This was likely due to high numbers of small boat arrivals that year, which were at that time still being detained initially for short periods on arrival within the detention estate.

The proportion leaving within 7 days is also lower than the years before small boat arrivals began happening frequently, when detention was more commonly used to prepare people for return.

Figure 3: People leaving immigration detention, by length of detention^1,2, year ending March 2020 to the year ending March 2024

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 March 2024 was bail (60%).

Figure 4 shows that bail was the most common reason for leaving detention for most of the top 10 nationalities, with the exception of Lithuania and Romania. 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 60% in the year ending March 2024. 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 the year ending March 2024.

Figure 4: Top 10 nationalities leaving detention by reason for leaving^1,2,3,4, year ending March 2024

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.
4. The numbers above each column refer to the numbers of people of that nationality leaving detention during the period.

The proportion of people leaving detention due to being returned has increased from 20% in the year ending March 2023 to 34% in the year ending March 2024.

In spite of this recent uplift, there has been a longer-term downward trend in detention leavers being returned. The proportion of people leaving detention due to being returned averaged 44% from 2015 to 2019, while the number of returns has fallen from an average of around 12,000 during these years to around 5,000 in the most recent 2 years.

The 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. More recent analysis shows that 41% of people detained for administrative removal in January to September 2022 were referred as potential victims of modern slavery while in detention, with the percentage rising every year since at least 2017.

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)

As shown in figure 5, the majority of returns are voluntary or port returns.

Figure 5: Returns from the UK, by type of return, year ending March 2015 to year ending March 2024

Source: Returns - Ret_D01

2.1 Enforced returns

In the year ending March 2024 there were 7,016 enforced returns, an increase of 70% on the previous year (4,127).

Enforced returns have been increasing steadily over the last 2 years, as shown in figure 5, with the total for the year ending March 2024 being more than double that in 2021 (2,788), when pandemic travel restrictions made returns difficult. Enforced returns are now at a similar level to where they were in 2019 (7,198), just prior to the COVID-19 pandemic.

As shown in figure 6, the increase in enforced returns this year was largely driven by Albanian returns which increased from 1,068 in the year ending March 2023 to 2,842 in the year ending March 2024 (accounting for 41% of returns in that period). 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.

Total enforced returns tend to include substantial numbers of enforced returns of foreign national offenders (FNOs) and asylum-related enforced returns. During the year ending March 2024, asylum-related enforced returns more than tripled compared with the previous year, following measures taken to tackle the asylum backlog in 2023. Numbers of enforced FNO returns also increased by around a third. For more information about FNO returns and asylum-related returns, which may include non-enforced returns, please see sections 2.4 and 2.5 in this chapter.

Figure 6: Enforced returns from the UK, by nationality¹; for the year ending March 2022 to the year ending March 2024

Source: Returns - Ret_D01

Notes:

1. Nationalities shown are the top 5 nationalities for enforced returns over the past 3 rolling years.

2.2 Voluntary returns

Voluntary returns increased by 65% in the year ending March 2024 compared to the previous year.

In the year ending March 2024 there were 21,171 voluntary returns. As shown in figure 5, this continues the upward trend following the COVID-19 pandemic and is above pre-pandemic levels. However, voluntary returns are still 31% lower than the recent high in the year ending March 2016.

Demand for voluntary returns of all types has increased during the last 2 years. This has been the case across voluntary returns made with assistance from the Home Office’s Voluntary Returns Service (‘assisted returns’) and returns made independently, in the form of self-funded (‘controlled’) returns and those discovered through matching our database against passenger departures data (‘other verified returns’).

Brazilians have been the most common nationality returning via the assisted route since 2019, and the most common nationality arriving via assisted and controlled returns during the last 2 years. Brazil is classified as a developing country by the OECD and as such Brazilian nationals may be eligible for reintegration assistance to assist them to settle back in their home country. The maximum value available through the Voluntary Returns Service (who issues reintegration assistance) is £3,000. General reintegration support for people returning to a developing country, including Brazil, has been available since April 2021. Prior to 2021, a variety of individual reintegration packages were available up to a maximum value of £2,000.

2.3 Port returns

There were 23,957 passengers who were refused entry at port and subsequently departed (‘port returns’) in the year ending March 2024, similar to last year. Although the overall total has remained stable, certain nationalities have seen substantial increases in port returns (for example, Colombia up 167%, India up 77% and China up 352%) and decreases (for example, East Timor down 69% and Albania down 38%).

The nationality make-up of port returns has changed in the last few years. 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 2024 they accounted for 59%. Half (48%) of EU port returns in the latest year 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)

There were 4,150 FNO returns made in the year ending March 2024, an increase of one-third (34%) compared to the previous year.

The increase in returns of FNOs over the last year is linked to new measures to facilitate FNO removals.

Figure 7 shows that the number of returns of Albanian FNOs, following the agreement reached with the Government of Albania in December 2022, accounted for a large proportion (39%) of FNO returns during the latest year. Among other things, this agreement strengthened data sharing between the UK and Albania to identify Albanian FNOs living in the UK.

The Early Removal Scheme (ERS) enables the removal or deportation of FNOs at an earlier point in their sentence than would otherwise be possible. This scheme was extended in January 2024 to include FNOs who had up to 18 months remaining on their sentence, rather than those with just 12 months or less, increasing the pool of FNOs eligible for return. For more information please see the policy timeline document accompanying this release.

Figure 7: Returns of FNOs¹ from the UK, by nationality²; for the year ending March 2022 to the year ending March 2024

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.
2. Nationalities shown are the top 5 nationalities for enforced returns over the past 3 rolling years.

Returns of FNOs decreased between 2016 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 37% 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 the year ending March 2024, there were 6,956 asylum-related returns, more than double from the year ending March 2023 (3,476).

This is mainly due to an increase (from 1,336 to 3,898) in Albanian asylum-related returns, following higher volumes of refused and withdrawn Albanian asylum claims in the year ending March 2024.

The increase in asylum refusals and withdrawals follows improvements to asylum decision making capacity at the Home Office. This led to greater numbers of failed asylum cases who were eligible for removal.

For further information on the asylum system, see the ‘How many people do we grant protection to?’ chapter.

In the year ending March 2024, 24% of enforced and voluntary returns were asylum-related.

2.6 Small boat returns

Between 2018 and March 2024, there have been 3,168 returns of people who arrived by small boat, or 3% of all small boat arrivals during this time.

In the year ending March 2024, there were 2,178 returns of people who arrived by small boat, representing 8% of all enforced and voluntary returns during the year.

Numbers of returns are low relative to numbers of people arriving by small boat, because most of these irregular migrants claim asylum on arrival. Those claims that are unsuccessful must still undergo substantive consideration, or consideration under inadmissibility rules, before any steps can be taken to arrange a return. Since the beginning of 2023 88% of small boat returns have been Albanian nationals.

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

3. About the statistics

3.1 Immigration detention

The statistics in this section relate to detention solely under immigration powers. Statistics on foreign nationals held in prison for criminal offences are published by the Ministry of Justice in ‘Offender management statistics quarterly’.

One individual may enter or leave detention multiple times in a given period and will therefore have been counted multiple times in the statistics.

3.2 Returns

We 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 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.

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.