Guidance

Home Office statistics on exit checks: user guide

Updated 27 August 2020

1. Introduction

The ‘Fifth report on statistics relating to exit checks’ is an experimental statistics report that provides evidence on the behaviour of migrants, based on UK Visas and Immigration (UKVI) administrative data sources. The statistical release includes updated results on the proportion of non-EEA nationals who departed before their visa expired, as well as updated data quality metrics.

The findings presented are based on administrative data derived from the data matching system and analytical capability built by the Exit Checks Programme, the Initial Status Analysis (ISA). While the Exit Checks Programme closed in May 2016 having delivered its objectives, the ISA remains in place and is delivering results.

The purpose of this report is to inform users (including government, Parliament, the media and the wider public) of data on migrants’ compliance with visa expiry dates.

The current system of immigration control is based on the Immigration Act 1971, which came into force on 1 January 1973, and subsequent amendments to the law. Policy and operational changes, as well as overall factors which influence the levels of immigration, such as the economic climate, can affect the figures.

The latest publication, including data tables and commentary, can be found on the Fifth report on statistics relating to exit checks page on GOV.UK.

Previous reports in the series can be found at Migration Statistics.

1.1 Statistical or public enquiries

If you would like to make an enquiry about this release or have any general feedback about this release, please contact the Migration Statistics team by emailing MigrationStatsEnquiries@homeoffice.gov.uk

1.2 Media enquiries via Home Office news desk

Journalists with enquiries can call the Home Office news desk on 020 7035 3535. The desk operates from 7am to 8pm, Monday to Friday.

2. Conventions

2.1 Rounding

Data are provided unrounded. This is to promote transparency and allow users to exploit the data further. However, caution should be taken when comparing small differences between time periods.

While care is taken in collecting and collating all the information obtained, figures are subject to the inaccuracies inherent in any large administrative recording system and are not necessarily accurate to the last digit. There are a range of different types of errors possible, such as those resulting from recording errors or misclassifications.

Percentages are rounded to the nearest per 0.1 cent using the round-half-away-from-zero method. The round-half-away-from-zero method has been used so that in the borderline case where the fraction of the percentage is exactly 0.5, the rounded figure is equal to y + 0.5 if y is positive, and y - 0.5 if y is negative. For example, 23.5% is rounded to 24%, and -23.5% is rounded to -24%.

Where percentages are rounded, they may not total 100% because they have been rounded independently.

2.2 Use of symbols

The following symbols have been used in the tables:

z			Not applicable
:			Not available
0			Nil

2.3 Revisions to data

The data contained in the report are subject to revision every year. It is not possible to evaluate whether any future revisions will be upward or downward, however the reasons for revisions are likely to include:

• Late reporting of cases – a small proportion is not included when the statistics are produced. Similarly it is anticipated that further data on the travel of those using the ADS route will improve the compliance rate for this group, but the additional information has yet to be fully incorporated in the results shown due to data lags
• The results of data-cleansing exercises, such as data identified that cannot be included when the statistics are calculated because of missing or invalid values, or the identification of duplicates in the data.
• Additional information on individuals allowing better identification of identities and/or better matching.
• Development of improved methods, data quality improvements or better coverage.

3. Methodology and data quality

3.1 Overview of the Initial Status Analysis (ISA) system

The ISA system, developed by the exit checks programme, is a linked database that combines data from Home Office systems to build travel histories that consist of an individual’s travel in or out of the country, together with data relating to their immigration status, such as periods of leave granted. The exit checks programme put in place outbound data collection on scheduled commercial international air, sea and rail routes, providing an ability to identify those who have left and those who may have failed to leave the UK when they should have done so.

The following data is included within the ISA system:

• Advance Passenger Information (API) and Travel Document Information (TDI). API is passenger data submitted in advance of travel for most scheduled aviation journeys, while TDI is passenger data collected at the point of departure for other modes of transport.
• Data from case working systems relating to (out-of-country) entry clearance visa application casework and (in-country) casework e.g. on extensions of leave to remain.
• Biometric details submitted prior to visa applications.
• Passport examinations data collected upon entry into the UK. This data helps mitigate any gaps in inbound API coverage.

These data are matched in order to produce an ‘identity’ and to determine the current compliance status of an individual. Each individual within the ISA system is allocated a unique identifier which consists of biographic details (such as name, passport or travel document number, date of birth, nationality and gender) and associated events (such as travel in or out of the country or periods of leave granted). The resultant dataset is termed the ‘Initial Status Analysis’.

As with all large complex data collections based on administrative data, the data received may not always be complete and fully accurate. There are also a number of ways in which a traveller’s departure may legitimately not be recorded by the system, for example where outward travel is by the Common Travel Area (CTA), or when a traveller unfortunately dies in the UK.

3.2 Compliance analysis

Statistics on non-EEA nationals’ compliance with visa expiry dates excludes:

• The majority of visitors to the UK who do not need a visa for any reason, such as UK and EU nationals living overseas;
• Non-visa nationals, such as US citizens, who do not normally need a visa to visit the UK;
• Nationals of Gulf states visiting under the electronic visa waiver scheme;
• The minority of visit visa holders who have long-term visit visas, allowing multiple visits each of up to six months;
• Those whose entry clearance visa expired but who obtained settlement or other leave allowing them to continue to stay in the UK, who were therefore compliant. Consequently, the results presented understate true compliance levels, particularly for routes where a significant proportion obtain settlement or other leave allowing them to stay in the UK;
• Individuals who were not matched to a visa or leave to remain at the point of their last entry into the UK; and,
• Crew.

3.3 Coverage analysis

Coverage is a measure of the proportion of routes which are covered by the system for collecting API/TDI data on border crossings; all carriers on a specified route are required to provide data for their flights, voyages or rail journeys. A calculation is made of the estimated number of passengers who would have travelled on these routes but these are not estimates of the fraction of passengers for whom API/TDI data was received. They are a measure of the proportion of routes which have systems in place to collect API or TDI data

3.4 ‘Leave Instance’ Methodology

An important development to the statistical system, introduced from the third report onwards, has been the implementation of the ‘leave instance’ methodology. Previously, individuals were assigned a single compliance status relating to their latest period of leave. This approach meant that we did not have information about an individual’s past compliance at the point they applied for new leave. In contrast, under ‘leave instance’, an individual’s compliance is assessed at the end of each period of leave they have. For example:

• a student given a three-year visa will be assessed once at the end of that visa (irrespective of the number of times they enter or leave the country over the three years) so they will only have a single status in the ISA data system, in the same way as they would have had previously.

• an individual who is first granted a visit visa and is later granted a (non-overlapping) investor visa, will be assessed first at the end of the visit visa and then at the end of the investor visa, so will have a status in the ISA system at two different points.

• a visitor, who is granted five non-overlapping visit visas will be assessed at the end of each of these visas, giving them five statuses in the ISA system, at successive points, rather than the one they had previously only for the latest visit visa grant.

This means that we now have a richer source of information about the whole compliance history of an individual, can answer a wider range of questions about the pathway groups take through the immigration system, and can compare compliance more robustly over time.

3.5 Data matching and the ‘unmatched pot’

The ISA system combines data into identities that link an individual’s travel in or out of the country with their immigration history, to create, as far as possible, a person-centric dataset. Linking various immigration systems’ data combines events that have common indexes, while additional data-matching combines events that have common biographic details. The data matching uses deterministic, probabilistic and event-based matching methods. It is relatively easy to appreciate how each individual linking method operates in isolation; however, the combined effect of different methods working together is more complex. The ISA system has to cater for all (non-EEA nationals) and so matching needs to be intuitive enough to make best use of records with poor data quality but cautious enough to ensure that incorrect initial estimates are kept to a minimum. In doing this, work is done to also include records with limited data quality by employing multiple techniques and business logic.

The ISA system contains data on both visa nationals and non-visa nationals. Visa nationals are nationals of countries, such as India, China and Russia, for whom a visa is normally required to enter the UK. Non-visa nationals are nationals of countries, such as the United States, Canada and Japan, who are currently allowed to enter the UK without a visa as visitors for a period of up to six months. There is more confidence in data on visa nationals, because more information is held on them through their visa. Therefore, the quality of data matching is believed to be higher for visa nationals and so only data relating to visa nationals is included in this statistical report.

However, in some cases, we are unable to match records belonging to visa nationals to a visa or leave to remain at the point of their entry into the UK.

There are many reasons why automatic systems such as ISA might be unable to match an individual’s travel record to leave they have. Some of these reasons are:

• An individual could be a dual national who provided their visa national passport details as part of their API but subsequently entered the UK on a non-visa national, EEA national or British passport.
• An individual might travel on different documents to those held on immigration records (for example those who obtain a replacement to a lost passport).
• An individual could have a right to entry for which the Home Office does not have an electronic record, such as historical settlement rights documented on a vignette in a previous passport, or entry rights as the family member of an EEA national.
• Incorrectly entered biographic details (e.g. passport number, nationality or date of birth) may mean that the ISA system is unable to match the travel record to the rest of the information we hold about an individual, creating an ‘orphan’ identity that only contains the API record.

A range of further specific reasons for non-matching were identified via discussions with staff at the border:

• Right of Abode linked to indefinite leave to remain – Indians in particular presenting a BRP or old passport with this information that is not recorded on the immigration system.
• Dual nationality – a high rate of South Africans, for example, have dual documentation.
• Citizens of one nation carrying papers of another – e.g. Algerians carrying French identity cards, Moldovans with Romanian papers, Palestinians with documentation from other nations.
• Emergency papers – those granted asylum are issued with blue emergency travel documents that look like a passport. If those granted asylum subsequently travel abroad, they will record their nationality, e.g. on API records, whereas immigration records will record them as XXB. This code is used when it is not possible to independently verify the nationality of an individual, such as a refugee.
• Overseas British Territories – Overseas Nationals often record their nationality on API as GBR but on immigration records they are recorded as GBO not GBR.
• Electronic visa waivers (EVW) – entering on an EVW and then switching to a visa to extend their stay – particular to citizens of Gulf states.
• Passports of convenience – wealthy individuals (specifically Russians), buy an additional citizenship for a large fee enabling them to travel visa-free – this may account for data discrepancies.

Match rates can vary between nationalities which may, in part, be due to differences in the degree to which travellers use online application systems (electronic data being easier to match), consistency in presenting biographical information in different databases, or other reasons. For example, some nationalities may be more or less likely to be dual nationals with UK citizenship.

3.6 Other data quality issues

Below are some further examples of issues that have been investigated to improve the quality of data in the ISA system.

a) Correcting data errors through improved User Interfaces

Reviews of data submitted by several carriers have highlighted the potential for data entry errors resulting from the design of the User Interface (UI) used by passengers to enter their Advance Passenger Information (API) Data – relating to the use of drop-down menus to enter data. This has contributed to ongoing discussions, including with some carriers, on improving data quality.

b) Chinese ADS visa compliance and ISA

Chinese Visit Approved Destination Status (ADS) visa holders are a cohort for whom the results reported from ISA initially had an unexpectedly high rate of no ISA-matched departure recorded. Investigations reported in the ‘Second report on statistics being collected under the exit checks programme’ (August 2017), and subsequently, indicated that that the vast majority of these were likely to have departed the UK through routes not covered by the ISA system.

Subsequently, a feedback process was set up in collaboration with Home Office Beijing staff, and with assistance of the ADS travel agents, in order to improve the accuracy of ISA’s assessment of the compliance status of Chinese ADS visitors.

It is anticipated that further data on travel of those using the ADS route whose visa expired in 2018/19 and 2019/20 will improve the compliance rate for this group for later years’ data, but the additional information has yet to be fully incorporated in the results for these years due to data lags.

c) Data sharing with ONS to improve data quality of migration statistics

There is a cross-government programme of work to transform UK’s population and migration statistics, including the use of ISA data. The ongoing results of the work were reported by the Office for National Statistics in their article Population and Migration Statistics System Transformation Overview.

On 14 February 2020, the ONS also published Alternative Definitions for International Migration using Home Office Exit Checks data.

4. Operational and policy context

Since 2010, a range of measures have been implemented to improve compliance with the UK’s immigration system. These policy changes have, for example, contributed to an increase in visa grant rates, from 73% in the year ending March 2010 to 97% in the year ending March 2020 for non-EEA sponsored students, and from 87% in the year ending March 2010 to 97% in the year ending March 2020 for visas granted to non-EEA nationals on work routes. These changes suggest that more recent cohorts of visa holders (whose compliance rates are presented in this report) may be more compliant than those whose visas expired in earlier years.

See Chapter 1 in the Second Report on Statistics being Collected Under the Exit Checks Programme for a detailed explanation of policy and operational changes from 2010 to 2016, in particular for the work and study categories.

4.1 Factors affecting the statistics

Immigration Rules, which are laid before Parliament by the Home Secretary, govern the entry and refusal of entry of passengers into the UK, the conditions of stay in the UK, the variation of such conditions following entry, settlement, and the deportation or removal of individuals.

Immigration Rules are stated in ‘Statement of changes to the Immigration Rules’ HC395, which took effect from 1 October 1994. This consolidated previous rule changes, although there have been changes to the rules since 1994.

4.2 Background and changes in legislation and policy affecting the statistics

Tier 1 (High value)

Tier 1 of the PBS was phased in between February and June 2008 as a general route. However, from 2010, Tier 1 has focused on providing visas for ‘High value’ migrants only, including the exceptional talent route, investors and entrepreneurs.

The Tier 1 Entrepreneur route was closed to most new applicants in March 2019 and replaced by the non-PBS Innovator route. The Tier 1 Graduate Entrepreneur route was closed to new applicants in July 2019 and replaced by the non-PBS Start-up route. The Tier 1 Exceptional Talent route was closed to new applicants in February 2020 and replaced by the Tier 1 Global Talent route.

Tier 2 (Skilled)

Tier 2 of the PBS is the primary route for economic migration to the UK. Broadly, the route is for skilled workers from outside the EEA who have an offer of employment in the UK in an occupation classed as skilled to NQF6 or above.

Tier 2 was implemented in November 2008. There are four routes within Tier 2: General, Intra-company transfer, Minister of religion and Sportsperson.

Tier 4 (Sponsored study)

Tier 4 (Sponsored study) provides a route for students to study with an approved education provider. It was implemented from 31 March 2009, replacing previous entry routes for study.

Tier 5 (Youth mobility and temporary workers)

Tier 5 (Youth mobility and temporary workers) was implemented in November 2008 to provide a route for those coming to the UK for primarily non-economic reasons.

The Tier 5 Seasonal workers route was open to new applicants from January 2019.

5. Other sources of information on immigration and migration

Delivering statistical benefits from e-Borders ONS research report, 2012

An inspection of exit checks (2018) The Chief Inspector’s report on the Home Office’s Exit Check Programme

Response to an inspection report on exit checks (2018) Home Office response to the Independent Chief Inspector of Border and Immigration’s report on an inspection of exit checks

Research Reports on immigration control are published by Home Office Analysis and Insight as reports and occasional papers

Immigration Statistics releases, including data tables and commentary, can be found at

The dates of future editions of Home Office statistical outputs can be found via the UK National Statistics Release Calendar