How many people are detained under immigration powers in the UK?
Published 27 November 2025
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Data on detentions relates to the year ending September 2025 and all comparisons are with the year ending September 2024 (unless indicated otherwise).
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. People entering immigration detention
The number of people entering detention increased in the year ending September 2025, continuing the recent upward trend since 2023.
A total of 22,661 people entered immigration detention in the year ending September 2025, 17% more than the previous year. This increase continues an upward trend since 2023.
Figure 1: People entering immigration detention in the UK, from 2015 to the year ending September 2025
Source: Immigration detention - Det_D01
Figure 1 shows a reduced use of immigration detention compared to a decade earlier, with a sustained fall in numbers of people entering detention from 32,447 people in 2015 to 24,480 in 2019 that has not been fully reversed since. This fall can in part be linked to the Government’s response to the 2016 Stephen Shaw review of detention, which proposed a range of changes in the use of detention and greater use of alternatives.
Although the COVID-19 pandemic impacted detentions in 2020 and 2021, the general downward trend in the number of people entering detention continued up to the year ending September 2023. This decline occurred against the backdrop of detained individuals more commonly raising issues while in detention (such as asylum or modern slavery claims), combined with ongoing efforts to minimise the use of detention following the Shaw review, which contributed to decisions to manage such individuals in the community rather than within the detention estate.
Although detention is typically used to facilitate a return from the UK, in 2021 many entrants were small boat arrivals detained for initial processing on arrival. From 2022, the Manston immigration centre opened to process small boat arrivals, which meant that such people were no longer being held within the detention estate for initial processing, leading to a further decline in numbers entering. The Manston facility allowed more individuals to move directly to community-based accommodation following the initial examination and checks.
The recent increase in numbers entering detention may in part reflect the use of detention to facilitate returns from the UK. This is evidenced by a 17% increase in detention intake in the latest year, coinciding with a 19% rise in numbers of returns from detention (see ‘How many people are returned from the UK?’ for more information). A sustained increase in the number of people being returned from detention, despite no additional centres opening over the period, is partly a result of measures to improve how current estate capacity is used.
Albanians represented nearly a quarter (23%) of people entering detention in the year ending September 2025.
Despite Albanians remaining the most common nationality entering detention (5,116 entries), this is 35% below the peak in the year ending September 2022 (7,861) when a record number of Albanians arrived by small boat and many were either detained on arrival, or returned from the UK. The lower numbers entering detention in recent years may reflect a declining population of Albanians eligible for removal, given the shrinking asylum-seeker caseload, and declining prison populations of these nationals.
The next most common nationalities were India (14%) and Brazil (13%), which have seen entries approximately double in the latest year to 3,242 and 2,931 respectively.
2. People in immigration detention
The number of people in detention on 30 September 2025 was 12% higher than a year prior.
There were 1,962 people being held in detention (at an immigration detention facility or in prisons under immigration powers) at the end of September 2025, 12% more than a year earlier.
Figure 2 shows that while there has been relative stability in numbers held in detention over the last 2 years, numbers decreased sharply at the start of the COVID-19 pandemic, and fluctuated greatly during 2021 and 2022. They have since stabilised at levels similar to those seen in 2019 prior to the pandemic.
The vast majority of people detained under immigration powers are detained in the detention estate rather than prisons. On 30 September 2025 there were 101 foreign national offenders (FNOs) detained in prisons and this number has been around 100 since the second half of 2023 when some FNOs who had served their custodial sentence in prison were transferred into the detention estate if assessed as suitable. Prior to this, the number of people detained in the prison estate had been much higher, ranging between 300 and 700.
While many FNOs subject to deportation action are detained in the detention estate and prisons, many are managed in the community. For data on those managed in the community, see the Immigration Enforcement Transparency statistics.
The total number of foreign nationals held in prison for criminal offences can be found in the latest prison population statistics, published by the Ministry of Justice and HM Prison and Probation Service.
Figure 2: People detained under immigration powers in the UK, on the last day of the quarter, 31 December 2017 to 30 September 20251,2
Source: Immigration detention - Det_D02
Notes:
- 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.
- Prisons data for dates from 31 December 2022 includes prisons in England and Wales only.
The number of people in detention is a snapshot relating to a single point in time, therefore, numbers fluctuate daily. If a large number of people entered detention just before the end of a reporting period, the number of people in detention would be higher than if the same people entered a few days later.
3. People leaving immigration detention
The most common reason for leaving detention in the year ending September 2025 was bail.
Figure 3 shows that over half of those leaving detention (11,646 or 52% of leavers) left on immigration bail in the latest year. Despite proportions fluctuating over the last few years, bail has been the most common reason for leaving detention since 2015; prior to 2015 the most common reason for leaving detention was to be returned.
People are bailed for a variety of reasons, including where there is no immediate prospect for their removal from the UK, or while their asylum claim is being considered, if they have made one.
Detained individuals who claim asylum, or raise other claims (for example, modern slavery or human trafficking) or further submissions (for example, appeals) which affect the progress of their removal, are usually bailed into the community. From there they will be monitored until their claims are concluded. If a claim is refused, the individual may depart the country voluntarily or re-enter detention if required to facilitate enforced removal.
Figure 3: People leaving detention by reason for leaving1,2 from 2010 to the year ending September 2025
Source: Immigration detention - Det_D03
Notes:
- Other reasons for leaving detention include being sectioned under the Mental Health Act, entering criminal detention, 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.
- The legend follows the same order and orientation as the stacks within the chart.
Just under half (43%) of people leaving detention were returned from the UK in the year ending September 2025: a similar proportion to prior to 2018.
There were 9,653 cases of people leaving detention to be returned from the UK in the latest year, constituting 43% of total leavers. The number of returns from detention has increased by nearly 2.5 times over the last 3 years. Enforced returns from detention are the most common type of enforced return and has been rising steadily since the pandemic in 2020 and 2021. For more information about this trend, and the reasons behind it, see the ‘How many people are returned from the UK?’ topic.
Numbers of people being returned from Family accommodation units in PDAs are published in the quarterly Immigration Enforcement Transparency statistics.
For the top 3 nationalities leaving detention in the year ending September 2025 (Albania, India, Brazil), the majority of individuals were bailed.
Reasons for leaving detention varied across nationalities. Nationalities featuring prominently in FNO returns, such as Romanian and Polish nationals, were generally more likely to be returned from the UK than to leave on bail in the latest year. Some nationalities who featured commonly in asylum claims statistics in the latest year, including Indians and Brazilians, were more likely to leave detention on bail whilst their claims are being considered.
Albanians were the most common nationality leaving detention in the year ending September 2025 (5,278 or 24% of total leavers). Albanians are prominent across both the FNO and asylum claiming cohorts with a similar number returned from detention and leaving on bail. For more information about asylum claim statistics, see the ‘How many people claim asylum in the UK?’ topic.
Figure 4: People leaving immigration detention, by length of detention1, proportions of rolling annual totals, from 2010 to the year ending September 2025
Source: Immigration detention - Det_D03
Notes:
- Month duration refers to a period of 30 days.
Two-thirds of individuals leaving immigration detention in the year ending September 2025 had been detained for less than a month, of which one-quarter were detained for less than a week.
Figure 4 shows that from 2010 to 2019, prior to the rise in small boat arrivals, the most common length of detention was one week or less (averaging 37% of leavers annually). More recently the most common length of detention has been over one week to less than one month (40% of leavers in the latest year). In contrast, the proportion of people detained for one month and over has remained largely similar throughout the period, and since the pandemic has returned to around this level, at 33% of people detained in the latest year.
Individuals being returned from detention during the year ending September 2025 were more likely to be held for shorter periods of under a month in detention compared to those being bailed (72% compared to 62% respectively). Of the cohort of leavers being returned, 34% spent under a week in detention, compared to 20% of leavers being bailed.
Longer stays in detention (3 months and over) have ranged between 7% and 10% of numbers leaving over the last 4 years. In the year ending September 2025, 8% of people leaving stayed over 3 months.
4. About the statistics
The statistics in this section relate to detention 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.
As outlined in the intention to publish statement released by the Home Office in April, there are changes to FNO data collection and infrastructure currently underway, and once complete the Home Office expects to publish further statistics on FNOs in the immigration system.
5. Data tables
Data referred to here can be found in the following tables:
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