1. Introduction

There are three primary routes of immigration to the UK: work, study and family reasons. This paper examines some of the available data sources for measuring different aspects of family-related international immigration. The paper explores the definitional and coverage differences of each data source and provides users with advice on the most appropriate data source to meet their needs.

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2. Data sources

This article covers four distinct sources of information, two of which are only available for those subject to immigration control. All are used to help understand immigration of individuals for family reasons.

The International Passenger Survey (IPS), published by Office for National Statistics (ONS), provides estimates for long-term (where a person’s residence changes for 1 year or more) immigration into the UK that are published quarterly in the Migration Statistics Quarterly Report (MSQR). Estimates are available for main citizenship groupings and reason for migration (family immigration is measured by those who give “accompany or join” as their main reason for migration and includes those who accompany or join an employer).

Entry clearance visa (ECV) data, published by the Home Office, provides numbers of visas (indicating intention to visit the UK) by nationality (includes ECVs issued for family reasons, as well as dependants of those issued ECVs for non-family related reasons, and European Economic Area (EEA) family permits that allow entry of non-EEA nationals as family members of EEA or Swiss nationals).

Admissions data, published by the Home Office, provides numbers for admissions of non-EEA nationals into the UK, by nationality and route (including family admissions and other dependants).

ECVs and admissions cover those individuals subject to immigration control. For further details of the coverage, see Annex A and the User Guide to Home Office Immigration Statistics.

The Annual Population Survey (APS) and Labour Force Survey (LFS), published by ONS, estimate the UK migrant stock by nationality and country of birth and original reason for migration. The “WHYUK” variable reported from the surveys allows identification of individuals accompanying a migrating partner and individuals joining UK citizens. It should be noted that of those whose original reason for migration was not work, some do participate in the labour market (see The reason for migration and labour market characteristics of UK residents born abroad). However, given this is a measure of stock of the UK household resident population, it is not appropriate to use it to derive a measure of international migration flow. The dataset has been included for completeness but from here onwards no comparisons are made.

Further detail on these data sources are presented in Annex A.

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4. Differences between data sources

Although the three sources of flows show similar trends in non-EU family immigration over time, they cover different definitions of “family”, meaning that there are absolute differences in the levels of immigration.

Short-term migration (less than 1 year) is included within the routinely published entry clearance visa (ECV) and admissions data but is excluded from the standard definition of a long-term migrant used by the International Passenger Survey (IPS); visa length are available but may not provide a reliable measure of stay within specific sub-categories. For example, some individuals extend their stay to 1 year or more after arrival in the UK or may obtain immediate settlement (permission to stay permanently).

IPS estimates, based on the “accompany or join” reason, will not include individuals who report that their main purpose is another immigration route (for example, those family members whose main reason for migration is to work or study), as some individuals may also be migrating for family-related reasons.

IPS estimates are based on intentions collected from a sample survey and are subject to sampling error, whereas administrative data provides detailed data on administrative decisions used to manage case working process.

ECVs may over-estimate family long-term immigration, as issued visas may not actually be used or may be used for short-term migration. Admissions data is not available to separately identify some categories such as European Economic Area (EEA) family permits, or the “family re-unification” category for family members of refugees who have been given settlement (“family reunion” cases are likely to be recorded under “other”).

Differences between the sources are summarised in the table in Annex B.

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5. Guidance for users analysing family data

International Passenger Survey (IPS) data provide non-biased and easily-accessible estimates of changes in long-term family immigration for all nationalities and is the best source of information for change in total long-term family immigration through time. Given the estimates are based on a survey, caution should be taken when interpreting results due to the inherent sampling variability associated with a survey.

Users should be aware of the confidence intervals around these estimates, which will reflect the relatively small sample size for this main reason of visit. The IPS may also categorise individuals differently to the category within the administrative data source, for example, some family members who migrate may state they do so for other reasons than that shown on the visa used to enter the UK, such as for work or to study, and therefore do not necessarily state that “accompany or join” is their main reason for migration.

Entry clearance visas (ECVs) indicate intentions rather than actual immigration, but are the most complete source of information of non-European Economic Area (EAA) nationals who are coming to the UK for family-related reasons. The data are also able to provide a higher resolution analysis of family sub-categories and an indication of those visas issued for 1 year or more. Visas by length are not routinely published.

For the ECV sub-category “family”, determining long-term immigration is more complex than taking visa lengths of 1 year or more, as short-term “family” ECVs and some other ECVs can be extended when in the UK. Statistics on changes in migrants visa and leave status: 2015 (previously the “Migrant journey”) indicated that the vast majority of individuals arriving under the ECV sub-category “family” (short- and long-term) still had valid leave at the end of 1 year (from 2010 cohort, 3% of family visas had expired at end of the year (Table MJ01).

Admissions are a useful comparator with ECVs for non-EEA family arrivals and the additional sub-categories “work dependant” and “study dependant”. Users should be aware that admissions measure journeys, not individuals, and will include both short-term and long-term arrivals. However, a person will count against their visa category for the first arrival and subsequent arrivals on the same visa will be recorded as “returning resident” separate from the “family” totals.

The Annual Population Survey (APS) and Labour Force Survey (LFS) are a measure of stock and as such are not used as a primary estimate of immigration flows for family and dependant routes. The APS and LFS data may be used separately to study the resident household population of the UK and those who migrated with others or to join residents.

We are collaborating and data sharing across government to improve the information that is currently available to understand migration as described in our future work programme: International migration data and analysis: Improving the evidence.

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6. Annex A: Data source descriptions

International Passenger Survey (IPS)

The IPS collects data from individuals via face-to-face interviews with passengers at ports and on routes into and out of the UK. The IPS is carried out 362 days a year and approximately 90% of passengers entering and leaving the UK are covered within the survey’s sampling frame. Around 700,000 IPS respondents are screened by the IPS each year. Of these, around 4,000 interviewees are identified as long-term migrants – people who intend to change their normal place of residence for a year or more.

The IPS also has additional uses in estimating numbers of visitors and short-term migrants. Individuals identified as long-term migrants complete the Migrant Trailer, which collects information on reason for migration, including accompanying or joining another individual (that is, family-related migration). Details of ONS methodology for long-term migration and on IPS Quality Information in Relation to Migration Flows are published.

Entry clearance visas (ECVs)

Different nationalities have different entry clearance visa requirements for entering and staying in the UK: European Economic Area (EEA) and Swiss nationals do not require a visa to come to the UK. For over 100 other nationalities, covering three-quarters of the world population, a visa is required for entry to the UK for any purpose or for any length of stay (that is, “visa nationals”).

For the remaining nationalities (often referred to as “non-visa nationals”) a visa is required for those wanting to come to the UK for over 6 months, or for most purposes except as a visitor or as an individual in the short-term study category formerly known as “student visitors” (for which dependants are not allowed nor are extensions of stay). All those non-EEA nationals entering the UK in the “family” or “accompany or join” categories or as dependants of those with work or study entry clearance visas would require a visa.

EEA family permits are documents that facilitate the movement of nationals of countries outside the EEA who are family members of EEA nationals.

Entry clearance visas must be obtained prior to entry from a British diplomatic post abroad. Visa data (name, date of birth, nationality, visa type, visa length etc.) are recorded and centrally collated on the Central Reference System (CRS), from which data are extracted and provided to Migration Statistics to collate the data for publication. Full details are available in the Home Office Migration Statistics User Guide.

The Home Office report, Entry clearance visas by length, presents analysis on the length of entry clearance visas issued outside the UK.


Admissions data relate to the number of journeys made by people entering the UK. Where an individual enters the country more than once, each arrival is counted. However, a person will count against their visa category for the first arrival. Subsequent arrivals on the same visa will be recorded as “returning resident” (so are not included in the “family” total).

The total number of UK arrivals is derived from monthly returns made by Border Force staff based at 40 border control points (ports). Data from smaller ports are collated and included in the returns made by these ports. In the small number of cases where data are not provided by a port, data are sourced from other organisations (such as the Civil Aviation Authority, Department for Transport and Eurotunnel).

Statistical information on non-European Economic Area (EEA) nationals is sourced from landing cards after a passenger has been allowed entry to the country. The cards are separated into two main arrival types: non-controlled and controlled.

Non-controlled relates to those passengers entering the UK on standard conditions of entry (for example, non-visa visitors; passengers in transit; and passengers returning after a temporary absence abroad) and are not relevant to family immigration estimates.

Controlled cards are completed by visa nationals, along with non-visa nationals arriving to the UK via non-standard conditions of entry (that is, not as a visitor or in transit). Information from controlled cards is sent to a central point within the Home Office, where relevant information is extracted.

EEA family permits and family re-union cases are excluded from the admissions estimates as they are captured within a separate non-family category. There is not currently a means of accurately calculating admissions of these family-related cases.

Full details are available in the Home Office Migration Statistics User Guide.

Annual Population Survey and Labour Force Survey

The Labour Force Survey (LFS) is a survey of households living at private addresses (most communal establishments are excluded) in the UK. Its purpose is to provide information on the UK labour market, which can then be used to develop, manage, evaluate and report on labour market policies. Each quarter’s LFS sample is made up of approximately 12,000 households.

The Annual Population Survey (APS) combines data from four successive quarters of the Labour Force Survey (LFS) with rolling-year data from the English, Welsh and Scottish Local Labour Force Survey (LLFS), with a total sample size of approximately 122,000 households. More information about the LFS methodology is available.

These surveys provide UK stock estimates of the resident population of the UK by nationality and country of birth. The authoritative stock measures for the UK come from the decennial Census, but APS and LFS allow trends to be measured over shorter time scales.

The Home Office report, The reason for migration and labour market characteristics of UK residents born abroad, describes adults born abroad main reason for originally coming to the UK (WHYUK variable), this includes “family reasons”.

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7. Annex B: Summary of differences between sources

Notes for Table 1:

  1. Migration Statistics Quarterly Report Statistical bulletins.

  2. International Migration - table of contents.

  3. Home Office: Migration statistics (see Immigration Statistics Data Tables, Entry Clearance Visas Table vi_01_q).

  4. Home Office: Migration statistics (see Immigration Statistics Data Tables, Admissions Table ad_02_q).

  5. Home Office: The reason for migration and labour market characteristics of UK residents born abroad.

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