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The UK’s asylum backlog

03 May 2024

The UK has accumulated a large backlog of asylum cases. This briefing examines what we know about the asylum backlog, its causes, and its consequences.

  1. Key Points
    • Between 2018 and 2022 the UK’s asylum backlog increased sharply from 27,000 to 132,000 applications. It fell by 28% in 2023 following several government measures to process applications faster.
    • The number of asylum caseworkers increased sharply in 2023, and productivity recovered after a long period of decline.
    • The Prime Minister pledged to clear the ‘legacy’ backlog of older asylum claims by the end of 2023. The government processed 96% of these claims that year, but 3,900 applications remained.
    • Just over half of applicants awaiting decisions at the end of 2023 faced new rules that make it much harder for them to receive legal status in the UK. This is due to the Illegal Migration Act of 2023.
    • One reason the backlog fell in 2023 was that a larger number of claims were withdrawn (around 24,000 that year, over four times more than the year before). This includes claims withdrawn by the government. However, many of these people later re-entered the asylum system.
    • Slow asylum decision-making is financially costly and hampers refugee integration.
    • Some other high-income countries have also struggled with asylum backlogs. At the end of 2023, the UK had the fifth-largest asylum backlog in Europe.
  1. Understanding the Evidence

    The asylum backlog is the number of asylum claims awaiting a decision – typically, an initial decision from the Home Office. ... Click to read more.

    The best data on the asylum backlog is found in the Home Office’s Immigration System Statistics quarterly release (Tables Asy_D03 and Asy_10).

    In any given period, the change in the size of the asylum backlog is driven by the number of new asylum applications, minus the number of “substantive decisions” and withdrawn applications. The backlog grows when more people apply than receive decisions (or are withdrawn). Conversely, the backlog shrinks when there are more decided and withdrawn applications than new applications.

    Substantive decisions on asylum claims are either grants of protection or refusals. Withdrawals are counted as non-substantive initial decisions and can be either explicit or implicit. Explicit withdrawals occur if the claimant notifies the Home Office that they no longer wish to pursue their asylum claim. Implicit withdrawals are made by the Home Office if the claimant fails to maintain contact or provide up-to-date details, leaves the UK prior to the conclusion of the application, fails to complete an asylum questionnaire within the provided deadline, or fails to attend reporting events or personal interviews. Withdrawals may thus be viewed as non-substantive decisions, but they nonetheless remove a case from the asylum backlog. In August 2023, new immigration rules allowed officials to classify a broader range of asylum claims as withdrawn.

    Depending on what is included, there are different counts of the asylum backlog.

    The most commonly used count is applications awaiting an initial decision from the Home Office (an administrative decision) and therefore excludes those awaiting the outcome of an appeal to an immigration tribunal (a judicial decision). Other counts include asylum applications at any stage of the administrative or judicial process and hence include applications awaiting an initial government decision, as well as those awaiting the outcome of an appeal. Some figures cited in public debates include people who have been refused and have exhausted all rights of appeal but have yet to be removed from the country. In this briefing, we focus on applications awaiting an initial decision from the Home Office, because this makes up the large majority of pending cases and accounts for most of the growth in the asylum backlog over time.

    The asylum backlog figure is larger if family members are included. Each asylum application requests protection for a ‘main applicant’, and some include requests for protection for the main applicant’s close family members, known as ‘dependants’. These dependants include a partner and any children under 18, but not parents, siblings, extended family, or adult children. The dependants on an application receive the same outcome as the main applicant.

    Because only one asylum decision is taken per application, this briefing generally refers to applications rather than people (main applicants only). There are, however, some circumstances where it makes more sense to speak of the number of people in the backlog, such as in discussions around the number of asylum seekers in need of accommodation.

    Finally, the Home Office publishes data on the asylum ‘work in progress’, known as the ‘WIP’. This is the widest measure of the backlog and refers to the total number of people in the asylum system: (1) applicants awaiting an initial decision; (2) those awaiting an appeal outcome; (3) individuals who have been recorded as having absconded; (4) those whose claims have been treated as implicitly withdrawn due to their failure to complete an asylum questionnaire or attend a substantive asylum interview; and (5) unsuccessful asylum applicants awaiting removal from the UK. As of 30 June 2023, the asylum WIP stood at 215,308.

  1. Understanding the Policy

    The ‘legacy’ and ‘flow’ backlogs. ... Click to read more.

    In a speech to the House of Commons on 13 December 2022, Prime Minister Rishi Sunak pledged to clear the asylum backlog by the end of 2023. This pledge was later clarified to refer not to the total backlog but only to the roughly 92,000 applications lodged before 28 June 2022, when the Nationality and Borders Act came into effect. These applications are the ‘legacy’ backlog.

    Applications submitted on or after 28 June 2022 constitute the ‘flow’ backlog. Added together, these backlogs make up the total backlog of asylum claims awaiting an initial government decision.

    In the Home Office’s ad-hoc statistics related to irregular migration, the ‘flow’ backlog is further broken down into three categories – the Nationalities and Borders Act (NABA) backlog comprising applications made between 28 June 2022 and 6 March 2023, the Illegal Migration Bill (IMB) backlog comprising applications made between 7 March 2023 and 19 July 2023, and the Illegal Migration Act (IMA) backlog comprising applications made on or after 20 July 2023. Unlike the ‘legacy’ backlog, people in all three ‘flow’ backlogs can be considered ‘inadmissible’ if the applicant is found to have a “connection” to a “safe third country”.

    However, applicants in the IMB and IMA backlogs who entered the UK without permission and have travelled through a safe third country cannot receive legal status in the UK unless the Home Secretary considers that their human rights are at risk or there are other exceptional circumstances. At the time of writing, most people in either the IMB or IMA backlogs can be refused asylum but cannot be granted it. At some point (when the legislation is brought fully into force), it will also no longer be possible for most IMA asylum seekers to receive a decision at all, even a refusal.

    Backlog reduction measures

    Approaches to dealing with asylum backlogs typically fall into one of the following categories:

    • Increasing the resources dedicated to processing cases, such as increasing staff numbers;
    • Increasing the efficiency of the asylum process, such as by simplifying guidance or introducing caseworker specialisation;
    • Prioritising applications from groups with particularly high or low success rates to make faster decisions on those cases;
    • Granting status to people with longstanding, unprocessed claims without completing the full asylum casework process.

    The Home Office strategy to reduce the backlog has focused on the first three of these categories.

    First, the government sharply increased the number of asylum caseworkers it employed—staff numbers nearly doubled to 2,500 between December 2022 and September 2023.

    Second, the Home Office introduced simplified procedures for certain types of asylum casework. In May 2023, a PACE (Prioritising Asylum Customer Experience) programme was rolled out across all asylum teams. During a pilot in Leeds in 2022, the programme experienced relative success, the rate of asylum decision-making from an average of 1.3 to 2.7 weekly decisions per caseworker.

    Third, in February 2023, the Home Office introduced Streamlined Asylum Processing (SAP) to deal with manifestly well-founded applications more rapidly. Under the process, citizens of six countries—Afghanistan, Eritrea, Libya, Sudan, Syria, and Yemen—would typically have their asylum claim determined on the basis of a completed questionnaire rather than a face-to-face interview. The Home Office selected these six nationalities because they had a high success rate at their initial decision.

    The Home Office also has a dedicated unit to process Albanian asylum claims, which had increased sharply in 2022. For more details, see the Migration Observatory commentary, Albanian asylum seekers in the UK and EU. 

    A 2020 review of asylum practices in Europe found that fast-tracking the least and best-founded cases can be an effective way to reduce the total number of people in an asylum backlog, although it can negatively impact applicants who are not fast-tracked if resources are diverted to more straightforward cases. The UNHCR has also argued that where cases are fast-tracked because they are considered less likely to succeed, governments need safeguards that remove certain applicants from the ‘fast track’ if their cases are more complex.

    In addition to the measures already implemented, some proposals to reduce the backlog involve granting status to people without full consideration of their asylum claims. This would typically be restricted to those who have been waiting a long time for a decision. For example, in 2022, Ireland granted status to all applicants who had been waiting for an asylum decision for at least two years as part of a wider regularisation programme. A UK example concerns the ‘backlog clearance’ programme, initiated in 2006 and continued under the Coalition government after 2010, which granted status to some people with long-standing asylum claims.

    The Prime Minister indicated in a parliamentary debate in December 2022 that he would not support “blanket amnesties, as happened in the past”. Previous Conservative and Labour governments offered status to people who had waited for long periods without a decision.

The UK’s total asylum backlog fell by 28% in 2023 after twelve years of growth

The UK’s asylum backlog – defined here as the total number of asylum applications awaiting an initial decision – stood at around 95,000 on 31 December 2023. That was 28% lower than a year before, showing that the backlog had started shrinking after a long period of sustained growth. Of all the applicants awaiting an initial decision, around 61% (or 58,000) had waited for more than six months (Figure 1).

Most of the increase in the backlog happened between 2019 and 2022. On 31 December 2018, the backlog stood at around 27,000 applications. It had increased almost five times by the end of 2022, to 132,000, exceeding the previous record highest level reached in 1999.

Figure 1

Before 2023, the backlog grew because Home Office decision-making did not keep pace with the number of applications. This was initially mostly due to fewer decisions being made per caseworker, as discussed further below. In 2021 and 2022, an increase in asylum claims was also an important factor.

The key reason the backlog shrank in 2023 was that the government made many more decisions on asylum claims (and withdrew more claims, as discussed below). It is not because the number of applications fell (Figure 2). In 2023, there were around initial decisions and withdrawals, compared to about 67,000 new asylum applications.

Figure 2

Several factors contributed to faster decision-making in 2023. The Home Office sharply increased the number of caseworkers making decisions. It also introduced new processes designed to streamline processing, including deciding certain asylum cases based on a written questionnaire rather than an interview and grouping together applications by nationality. See the ‘Understanding the Policy’ section above for more details.

By the end of 2023, the top nationality of applicants awaiting an asylum decision was Iranian, followed by Afghan and Albanian (Figure 3).

Figure 3

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Just over half of applicants awaiting decisions at the end of 2023 face new rules that make it much harder for them to receive legal status in the UK

Not all people waiting for asylum decisions will face the same rules. The backlog can be broken down into four groups (Figure 4). Two of the groups can receive asylum decisions as normal:

  • The ‘legacy’ backlog includes applications made before 28 June 2022, when the Nationality and Borders Act (NABA) came into force (dark blue in Figure 4, below); this is part of the backlog the Prime Minister pledged to address by the end of 2023.
  • The NABA backlog of applications submitted between late June 2022 and early March 2023.

Together, there were 43,000 applicants in these two groups as of 28 December 2023. They made up around 44% of the total backlog, and this share will decline over time.

Figure 4

The situation for people in the IMB and IMA backlogs (around 56,000 combined, as of late December 2023) is uncertain and the government’s plans for them remain unclear. At the time of writing, these applicants can be refused asylum, but they cannot be granted legal status in the UK if they entered the UK without permission, unless the Home Secretary considers that their human rights are at risk or there are other exceptional circumstances (for more detail, see Understanding the Policy).

The government came close to meeting its pledge to clear the ‘legacy’ backlog of older asylum decisions by the end of 2023 but did not succeed.

At the beginning of 2024, the government announced that “The Prime Minister’s commitment of clearing the legacy asylum backlog has been delivered”. The available evidence suggests this is incorrect. According to official government statistics, there remained around 3,900 cases at the end of 2023 – equivalent to 4% of the original 92,000 cases. The government announcement, based on data up to 28 December 2023, said that

“While all cases have been reviewed […], 4,500 complex cases have been highlighted that require additional checks or investigation for a final decision to be made.”

On 14 January 2024, the UK Statistics Authority, which monitors the use of official statistics in the UK, published a confirmation that the claim to have cleared the legacy backlog was misleading. It noted that:

“The average member of the public is likely to interpret a claim to have ‘cleared a backlog’ […] as meaning that it has been eliminated entirely, so it is not surprising that the Government’s claim has been greeted with scepticism and that some people may feel misled…”

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Around 24,000 asylum applications were withdrawn in 2023, over four times more than the year before

The number of withdrawn asylum applications rose sharply in 2023, which contributed to the decline in the backlog (Figure 5). Just over 24,000 applications were withdrawn during the year, up from around 5,300 in 2022. Withdrawals made up a similar percentage of all decisions in 2022 (22%) and 2023 (24%).

Charities and immigration lawyers have concerns about the Home Office’s approach to withdrawing applications, particularly given the government’s goal of clearing the legacy backlog by the end of 2023. Withdrawals can happen automatically if certain conditions are met, such as the application lacking an address, or the applicant failing to respond to letters within a five-day deadline

However, there is evidence that many people whose asylum applications were initially withdrawn later re-entered the asylum system. A January 2024 letter from the Home Office showed that half of all asylum cases withdrawn in the year ending 30 September 2023 had subsequently re-entered the asylum process and had either resulted in a grant of legal status (15%) or were pending an initial decision (35%). Another 32% remained in the UK, and the Home Office was trying to re-establish contact with them

Figure 5

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The number of asylum caseworkers increased sharply in 2023, and productivity recovered after a long period of decline

In response to the growing backlog, the Home Office significantly increased the number of staff processing asylum claims, known as asylum caseworkers or asylum decision-makers. At the end of 2023, there were around 2,400 caseworkers. This was close to the government’s goal of 2,500 caseworkers by September 2023. Numbers had been rising since a low of 260 caseworkers in 2016, but most of the increase happened in 2023 (Figure 6).

The productivity of caseworkers also recovered in the second half of 2023. In the last quarter of the year, there were an average of 16 initial decisions per caseworker, up from around 5 decisions per caseworker in the second quarter. This marked a reversal of previous trends of long-term decline – between the first quarters of 2016 and 2023, the number of average decisions per caseworker fell from 25 to 4 (Figure 6).

The amount of time caseworkers take to make decisions does not necessarily reflect their performance. Decisions that are made more quickly could be less accurate.

Figure 6

Declining caseworker productivity was a key reason behind the UK’s growing asylum backlog between 2016 and 2022. There is no definitive explanation for that decline, though several explanations are available:

  • Administrative problems and high staff turnover. A 2021 inspection of the UK’s asylum casework highlighted a number of key administrative problems, including inadequate training for caseworkers, a reliance on Excel spreadsheets, low morale, and high staff turnover. Few caseworkers spent more than 24 months in the role, although it took 12-18 months for them to achieve full proficiency. Annual turnover reached 46% in the 2021/22 fiscal year, up from an average of 33% in the previous three years. This fell to 25% in 2022/23, after the Home Office introduced measures to increase retention, including bonus payments for caseworkers who stay in their jobs for more than a year.
  • The end of the six-month ‘customer service standard’. Until early 2019, the Home Office had an internal target (or ‘customer service standard’) to process 98% of straightforward cases within six months. While the lack of a service standard may have exacerbated delays, caseworker productivity started declining three years before it was abandoned. It’s possible that abandoning the service standard was partly a consequence of slower decision-making rather than one of its main causes.
  • New rules on inadmissibility. In 2021, the UK government implemented new rules on ‘inadmissibility’, aiming to remove asylum seekers if the Home Office believes they could and should have claimed asylum in another country. These rules added two more steps to the asylum process, which may have increased processing times. The Home Office first assesses individuals for inadmissibility, then tries to find a safe country to accept an individual it deems to be inadmissible. If a person cannot be removed within six months, their asylum claim would normally be considered in the UK. In theory, one could argue that removing people to have their claims considered elsewhere would reduce the backlog. In practice, however, less than 0.01% of those assessed for inadmissibility had been removed from the UK as of the end of 2023 (for more detail, see the Migration Observatory’s commentary, UK policies to deter people from claiming asylum).
  • The suspension of the Detained Fast Track process. In 2015, a series of legal challenges forced the government to suspend an accelerated process of dealing with asylum claims called the Detained Fast Track (DFT). This allowed the Home Office to detain any adult applicant if it believed a decision on their claim was possible within 14 days. The vast majority of claims processed under the DFT were refused – around 99% between 2008 and 2010. These rapid decisions brought down average processing times. While the suspension of the DFT may have contributed to the slowdown in decision-making, it is unlikely to be its primary cause. From 2005 to 2014, fast-tracked applications only made up 5-18% of yearly asylum applications.

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Slow asylum decision-making is financially costly and hampers refugee integration

The asylum backlog has led to long waiting times for applicants. By the second quarter of 2023, only  12% of applicants received an initial decision within 6 months, down from 87% in early 2014 (Figure 7).

Figure 7

Of the roughly 19,700 applications that received an initial decision in the year ending 30 March 2023 (excluding withdrawals), 8% received their initial decision within 6 months, 21% within a year, and 56% took at least a year and a half (Figure 8).

Figure 8

Having a large backlog of individuals who must wait long periods for their asylum claim to be decided has important consequences.

For those who will be successful in their asylum claims, there is a mental health and integration cost of long waiting times. The government does not generally permit asylum seekers to work during this period and provides those who are destitute with £49.18 per week in asylum support costs to cover food and other living costs except accommodation. Asylum seekers in hotels that provide meals are instead given £8.86 per week to cover clothes, non-prescription medication, and travel.

A 2021 review of the research literature found that a shorter asylum waiting time had a large positive impact on long-term employment outcomes for asylum seekers who go on to be successful. A study in Germany similarly found that longer bans on work for asylum applicants were associated with lower employment rates in the future. Asylum seekers interviewed for a report by Refugee Action reported that waiting for an asylum decision causes stress and anxiety. A report by the House of Commons Library on asylum processing delays points to two additional academic studies that highlight the possible negative health consequences on asylum seekers of slow processing. The first is a 2018 paper published in the British Medical Journal on the health of ‘forced migrants’, including asylum seekers, which said that “Unemployment exacerbates social exclusion. Long periods of inactivity provide time to ruminate on past experiences and worries about the future.” The second study, published in 2022, examined the experiences of asylum seekers in Sweden. It found that “overwhelming uncertainty about the future and the indefinite waiting time for a decision” on asylum claims” caused “intense feelings of psychological distress” in participants.

For those asylum applicants who will be unsuccessful, longer waiting times increase the chance for them to form families or other ties that could hinder their removal.

In addition to the mental health and integration cost to asylum seekers, there is a financial cost to the government of slower decision-making. Many who claim asylum in the UK are destitute and require accommodation and support (see our briefing on Asylum and refugee resettlement in the UK). The larger the backlog, the greater the cost of providing this support.

In 2023, the government also struggled to source private rental accommodation in communities, which is its preferred way of accommodating asylum applicants. This has led to the widespread use of other kinds of accommodation, including hotels, B&Bs, detention centres, military sites, such as Napier Barracks and Penally Camp, and the Bibby Stockholm barge. According to data released by the Home Office in September 2023, the cost of housing asylum seekers in hotels stood at around £8 million per day. These costs would fall considerably if the backlog declined.

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At the end of 2023, the UK had the fifth-largest asylum backlog in Europe

Other European countries have large asylum backlogs. As of 31 December 2023, Eurostat data showed that Germany had the largest initial decision asylum backlog in Europe (referring to people rather than applications and so comprising both main applicants and dependants), followed by Spain, Italy, and France. With almost 129,000 people awaiting an initial decision, the UK had the fifth-largest backlog in Europe.

The UK’s asylum backlog is smaller than that of other European states if we consider its population. In large part, though, this is because the UK receives fewer applications per person than some of its peers – compared to the number of applications received in the previous three years, the UK’s backlog remains relatively large (Figure 9).

Figure 9

In the past, the UK took significantly longer to process asylum applications than its European counterparts. According to the most recent data from 2022, asylum applications took an average of around 21 months to receive an initial decision in the UK. Other countries with large numbers of asylum applications, such as Germany, Spain, and France, processed claims much faster (Figure 10). However, this comparison may have changed in 2023 because UK processing sped up significantly.

Figure 10


This research was made possible thanks to the support of Oak Foundation. Special thanks go to CJ McKinney for detailed comments on a previous draft of this briefing.


Mihnea V. Cuibus
Peter William Walsh
Madeleine Sumption

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