Immigration Detention in the UK

6th February 2015
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This briefing provides an overview of immigration detention in the UK. It discusses the size of the UK’s detention facilities, the number of detainees, the average duration of detention, and the detention of children.

Key points

  • The UK immigration detention estate is one of the largest in Europe. From 2009 until the end of 2013, between 2,000 and 3,500 migrants have been in detention at any given time.
  • Around 30,000 persons entered detention in 2013 compared to approximately 29,000 persons in 2012.
  • The majority of immigration detainees are held for less than two months.
  • The single most common category of immigration detainees is people who have sought asylum in the UK at some point.
  • Over 1,000 children were detained for the purpose of immigration control in 2009, and this number was reduced to just under 130 in 2011. It rose to 240 in 2012, before falling to 228 in 2013 with the majority detained at the Cedars pre-departure accommodation facility, opened in September 2011.
  • In late 2014 the estimated average cost of detention was £97 per day.

Understanding the evidence

Immigration detention refers to the government practice of detaining asylum seekers and other migrants for administrative purposes, typically to establish their identities, or to facilitate their immigration claims resolution and/or their removals.
The reasons for which a migrant may be held in detention include: to effect removal; to establish a person's identity or basis of claim; where there is reason to believe that the person will fail to comply with any conditions attached to the grant of temporary admission or release, i.e. a risk of absconding; where there is a risk of harm to the migrant or the public; and as part of the detained fast-track (DFT) system (whereby asylum seekers could be detained if their claims appeared straightforward and capable of being decided quickly). There are also occasions when` the reasons for a migrant’s detention change while he or she is already being held in detention.
Border officials in the UK may detain migrants: on arrival; upon presentation to an immigration office within the country; during a check-in with immigration officials; once a decision to remove has been issued; and after a prison sentence or following arrest by a police officer.
The publicly available data on immigration detention chiefly originate in publications released by the Home Office and Her Majesty’s Inspectorate of Prisons (HMIP). Data and information from non-governmental organisations’ reports, Hansard texts of Parliamentary debates and formal questions and scholarly articles supplement this information.

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The UK’s immigration detention facilities are among the largest in Europe: between 2,000 and 3,500 migrants are detained at any given time

The UK has one of the largest networks of immigration detention facilities in Europe. After the re-purposing of the Morton Hall prison as an immigration removal centre (IRC) in June 2011 and the opening of a short term holding facility at Larne House in North Ireland in July 2011, UK detention capacity expanded to approximately 3,500 places. As shown in Figure 1, over the past five years there have been between 2,000 and 3,500 migrants detained at any given time. As a snapshot example, just under 3,400 non-citizens were detained in UK facilities as of 30 September 2014.

Figure 1

Approximately 30,400 migrants entered detention in the UK in 2013

Approximately 30,400 migrants entered detention under Immigration Act powers in 2013, compared to 29,000 in 2012 and 27,000 in 2011 (UK Home Office 2014a). These statistics do not include persons detained in police cells, Prison Service establishments, short term holding rooms at ports and airports (for less than 24 hours), and those detained under both criminal and immigration powers and their dependents. Immigration detainees are held in Immigration Removal Centres (IRCs), Residential and Non Residential Short Term Holding Facilities (STHFs), and Holding Rooms either based at or near ports of entry and reporting centres.

As of January 2015, there were 11 IRCs, 4 RSTHFs, 1 NRSTHF, 1 pre-departure accommodation (for families), 19 Holding rooms at ports and 11 at reporting centres. Except for 4 IRCs that are managed by the Prison Service, the Home Office has outsourced the management of its detention facilities to private firms – Mitie, GEO, G4S and Serco. The contract for managing the Holding rooms, the NRSTHF and two of the four RSTHFs passed to Reliance (now Tascor) in 2011. Immigration detainees may also be detained in prisons and there is currently capacity for 600 detainees under a service level agreement with the National Offender Management Service.

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Over half of immigration detainees are held for less than two months

In 2013, about 81% of total immigration detainees leaving detention had been held for less than two months (Figure 2). It is also not uncommon for detention to span two to four months. A small but consistent minority of detainees – about 6% – are held for more than six months, including 1% held for more than a year.

Figure 2

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The most common category of immigration detention is people who have sought asylum in the UK at some point in their immigration adjudication processes

There are numerous categories of people who are detained under Immigration Act powers, and these categories can overlap. For example, new arrivals may be detained awaiting examination by an immigration officer to determine their right to entry; new arrivals who have been refused permission to enter the UK and are awaiting removal may also be detained; those who have either failed to leave the UK on expiry of their visas (so-called overstayers), have not complied with the terms of their visas, or have attained their visas by deception, may be detained; and undocumented persons found in the UK can be detained pending a decision on whether they are to be removed or pending arrangements for their removal.

The largest category of immigration detainees is persons who have sought asylum at some stage during their immigration processes. In 2013, asylum detainees accounted for about 60% of the total immigration detainee population (UK Home Office 2014a). The Government’s announcement in 2005 that it would process 30% of new asylum applicants through the detained fast track (DFT) system has contributed to the high numbers of asylum seekers in detention.

The immigration detainee population also includes foreign national offenders (FNOs), some of whom apply for asylum while in prison. Since April 2006, the UK Government has prioritised the removal of FNOs. As of 1 August 2008, with the introduction of the UK Borders Act 2007, all FNOs who have been sentenced to a period of imprisonment of 12 months or more are subject to automatic deportation from the UK unless they fall within one of the Act’s six exceptions. Prior to removal, FNOs who do not qualify for an exception remain in prison under immigration powers and are not counted in official detention estate statistics. Since 2009, more than 4,000 FNOs have been deported annually. (See our briefing on 'Deportations, Removals and Voluntary Departures from the UK'.) In February 2010, foreign national offenders were detained for an average of 143 days; by January 2011 this had increased to 190 days, an increase of 33% (Vine, 2011). As at 30 September 2012, there were 828 FNOs in detention (UK Home Office 2013). Automatic deportation, however, does not preclude appeal rights.

The policy primer on ‘Immigration Detention: Policy Challenges’ provides more context, explanation and analysis of Foreign national offenders and asylum seekers in UK immigration detention.

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Detention of children in 2013 was much lower than the 2009 levels

Throughout the 1990s, the Home Office rarely detained families with children. However, non-governmental organisations and other groups estimate the number of children detained with their families to have been up to 2,000 per annum between 2005 and 2009 (Crawley and Lester 2005, Sankey et al. 2010). Home Office statistics suggest that more than 1,100 children entered detention in 2009. This number fell to 436 in 2010 and to 127 in 2011. (Home Office 2014a). In 2012 and 2013 the numbers increased to over 200 annually, including 228 children entering immigration detention in 2013. The majority were detained at the Cedars pre-departure accommodation facility (Home Office 2014).

To deal with family cases without detaining children, on 1 March 2011 the government announced a new family returns process, having closed the family unit at Yarl’s Wood IRC in December 2010. The new process includes: a Family Returns Panel to consider child welfare issues in families who refuse to leave; a family conference to discuss future options and the specific option of assisted return; the opening of Cedars in September 2011; and the expansion and refurbishment of Tinsley House IRC at London Gatwick airport. Both Cedars and Tinsley House hold families for up to 72 hours and require a ministerial declaration for extending a family’s stay up to a week in exceptional cases.

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The financial costs of immigration detention

In answer to a 2007 request made under the Freedom of Information Act, the Home Office revealed that in 2005/6 the weekly cost per detainee ranged from £511 (Lindholme IRC) to £1,344 (Colnbrook IRC).

On 29 June 2011, the UK Government reported in Parliament that the average overall daily cost of detaining an individual at an immigration centre was £102 (Hansard 2011). Government data indicate that in the third quarter of 2014 the average cost per day of holding an individual in immigration detention was £97 (Home Office 2014b).

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Evidence gaps and limitations

It is important to recognise that any one source can be misleading in the presentation of data on immigration detention in the UK. For some time now, academics, journalists and activists have been requesting further information and clarification on the nature of the statistics on immigration detention released from the Home Office and the Office of National Statistics. The Home Office took steps to improve its dissemination of statistics in 2011. However, some gaps and limitations in the data remain. For example, information on the ethnic origins of the detainees is often difficult to determine. It is also difficult to track individual trajectories of detention, release and re-detention through the statistics because they are presented as separate numbers of occurrences. Such evidence gaps and limitations are important in discussions about how to access immigration detainees and provide them with services such as translation and visits.

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Related Material

With thanks to Mary Bosworth, Emma Kaufman, and officials at the Home Office.

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