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International migration estimates cover the flows and characteristics of long-term migrants between the UK and the rest of the world. These are people who intend to migrate for a period of at least one year. Statistics are available for short-term migrants (who migrate for less than one year).

Publications

Flag 4 GP Registrations by local authority
Department: Office for National Statistics
Flag 4 records indicate international in-migrants who register with an NHS GP. This dataset indicates, for each local authority in England and Wales, the number of new Flag 4 records added to the Patient Register during the mid-year to mid-year period.
Immigration Statistics
Department: Home Office
Quarterly and annual statistics relating to those: coming to the UK; extending their stay (temporarily or permanently); gaining citizenship; applying for asylum; and being detained or removed, as well as immigration for work, study and family reasons.
International Migration
Department: Office for National Statistics
The MN Series present statistics on flows of international migrants to and from the UK and England and Wales.
Long-Term International Migration
Department: Office for National Statistics
Estimates of Long-Term International Migration to and from the United Kingdom (UK) and England and Wales, annual statistics.
Long-term International Migration Estimates for Northern Ireland
Department: Northern Ireland Statistics and Research Agency
Summary report of sources which can be used to estimate long-term international migration in Northern Ireland.
Migration Indicators Suite
Department: Office for National Statistics
Comparison tool for indicators of migration at local authority level.
Migration Statistics
Department: Office for National Statistics
Annual report presenting and analysing UK migration data for the calendar year. This is a cross-government product.
Migration Statistics Quarterly Report
Department: Office for National Statistics
Collated migration data from the Office for National Statistics, Department for Work and Pensions and the Home Office, quarterly bulletin.
Migration Statistics, Wales
Department: Welsh Government
This statistical bulletin details migration estimates that measure the movement of people in and out of Wales.
National Insurance Numbers allocated to Adult Overseas Nationals
Department: Work and Pensions
Statistics on non-UK nationals registering for a National Insurance number for the purposes of work, benefits or tax credits. Release includes an update to Official Statistics on Nationality at point of National Insurance number registration of DWP benefit claimants
Short Term Migration Estimates for England and Wales
Department: Office for National Statistics
Short-Term international Migration statistics to and from England and Wales. Annual table and Bulletin.
Short-term migration estimates for local authorities in England & Wales
Department: Office for National Statistics
Estimates of short-term international in-migration at local authority level. This is a new product being published for consultation with users.

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Overview

Long-Term International Migration

The most comprehensive estimate of long-term migration into and out of the UK is Long-Term International Migration (LTIM). It is based primarily on migrants interviewed in the International Passenger Survey (IPS), but this survey does not include all types of migrants so the data are combined with other administrative sources.

LTIM is a combination of:

  • IPS flows

  • international migration to and from Northern Ireland

  • adjustments for people who change their intentions (switchers), and

  • adjustments for asylum seekers and their dependents

Some detailed analyses are only possible when based upon IPS data alone, therefore the published tables are grouped according to whether they are based on LTIM or IPS only. LTIM estimates are available for 1991 onwards, whereas IPS estimates are available from 1975 onwards.

Short-Term International Migration

Estimates of Short-Term International Migration (STIM) flows and stocks are based on the IPS, using data collected from people who have already completed their migration away from their country of usual residence for a period of less than a year. STIM estimates are available on three definitions; those migrating for 1-12 months, those migrating for 3-12 months and those migrating for 3-12 months for the purpose of work or study (based on the UN definition). Estimates of short-term inflows and outflows and instocks and outstocks are available at the national level for England and Wales. Estimates of short-term inflows only are also available at the subnational level of regions, counties, London Boroughs, unitary authorities and districts in England and Wales. All estimates are published annually on a mid-year basis. National level flows are available for the mid-years since 2004, whilst subnational inflows are available since mid-2008.

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Technical Data

Long-Term International Migration

In line with the UN definition, an international long-term migrant is defined by the Office for National Statistics as someone who moves to a country other than that of his or usual residence for a period of at least a year.

International migration is a key component of population change and is used in the production of population estimates and projections.

Long-Term International Migration (LTIM) is the most comprehensive estimate of long-term migration into and out of the UK. It is based primarily on a subset of the International Passenger Survey (IPS), namely those international passengers sampled by the IPS who are migrants entering or leaving the UK by principal air, sea and tunnel routes. The IPS component is supplemented with:

  • Data on international migration to and from Northern Ireland from the Northern Ireland Statistics and Research Agency (NISRA);

  • Home Office administrative data, which is used to calculate an adjustment for asylum seekers and their dependants not counted by the IPS; and

  • an adjustment for visitor switchers (those who intend to enter or leave the UK for less than 12 months but will actually stay, or stay away, for longer) and migrant switchers (those who intend to enter or leave the UK for at least 12 months without those intentions being realised).

Long-Term International Migration = IPS flows + Northern Irish flows + asylum seeker flows + visitor switcher flows - migrant switcher flows.

The estimates are published by citizenship; country of last or next residence; country of birth; main reason for migration; usual occupation; area of destination or origin within the UK; age and sex; sex and marital status; intended length of stay, actual length of stay; and route.

These flows do not indicate whether someone stays or leaves permanently. Therefore, they may not be added up on an annual basis to produce estimates of the population by country of birth or nationality.

The full methodology to estimate Long-Term International Migration can be viewed on the Office for National Statistics website.

Short-Term International Migration

Short-term international migration estimates are based on IPS data. However, unlike long-term international migration estimates, the IPS data used are based on interviews taking place at the end of each visit and so are not based on intentions. It is possible to use this different type of IPS data as, by definition, all short-term migration moves are completed 12 months after the move began, unlike long-term migrants who may never return to their country of origin. Estimates of short-term international migration are based on a range of definitions developed in consultation with users:

  • UN definition of short-term international migration (visits for between 3 and 12 months for employment or study)

  • Estimates of visits for all reasons lasting 3 to 12 months

  • Estimates of visits for all reasons lasting 1 to 12 months

Estimates are published as flows and also as stocks. The stock estimate refers to the average population present during the period and is supplemented by average length of stay. Both stock and flow estimates are accompanied by 95% confidence intervals. A 95% confidence interval shows the range within which, 19 times out of 20, the true value of the estimate would be expected to lie had all short-term migrants been surveyed.

 

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Glossary

  • Annual Population Survey

    The Annual Population Survey (APS) is a continuous household survey, covering the UK, with the aim of providing estimates between censuses of key social and labour market variables at a local area level. The APS is not a stand-alone survey, but uses data combined from two waves from the main Labour Force Survey (LFS) with data collected on a local sample boost. Apart from employment and unemployment, the topics covered in the survey include housing, ethnicity, religion, health and education.

  • APS

    Annual Population Survey. This is the Labour Force Survey plus various sample boosts.

  • Calibration

    An estimation procedure that constrains sample-based estimates of auxiliary variables to known totals (or accurate estimates). Calibration is used to improve the regional distribution of immigrants.

  • Citizenship

    The nationality of the passport that the traveller is carrying.

  • Citizenship

     This is the term used in the International Passenger Survey (IPS) to define the country for which a migrant is a passport holder. This refers specifically to the passport being used to enter / leave the UK at the time of interview. It does not refer to any other passport(s) which migrants of multiple nationality may hold. More generally a British citizen as described in IPS statistics includes those with UK nationality usually through a connection with the UK: birth, adoption, descent, registration, or naturalisation. British nationals have the right of abode in the UK.

  • Coherent reporting

    Under this initiative, key information on migration and migration-related statistics collected across government are now jointly released. This allows for a principal point of access to these statistics and added value to the outputs in terms of insight, expert analysis and commentary to describe the similarities or differences between the data and why these occur.

  • Commonwealth (ONS Statistical Grouping)

    The Commonwealth statistical grouping consists of countries of the Old Commonwealth and the New Commonwealth

  • Confidence interval

    A range within which the true value of a population parameter lies with known probability. For example the 95 per cent confidence interval represents the range into which there are 19 chances out of 20 that the true figure would fall (had all migrants been surveyed). This is obtained as +/- 1.96 times the standard error.

  • Country of usual residence

    The country in which a person has a place to live, where he or she normally spends the daily period of rest. Temporary travel abroad for purposes of recreation, holiday, visits to friends and relatives, business, medical treatment or religious pilgrimages does not change a person’s country of usual residence (UN-based definition).

  • EEA

    European Economic Area consists of the EU Member States plus Iceland, Liechtenstein and Norway.

  • Emigrant (Outflow)

    A person who leaves their country of usual residence to take up residence in another country for a period of at least 12 months.

  • Estimate

    An indication of the value of an unknown quantity based on observed data.

  • EU15

    European Union as constituted between 1 January 1995 and 1 May 2004. The following 15 member states were included: Austria, Belgium, Denmark, Finland, France, Germany, Greece, the Irish Republic, Italy, Luxembourg, Netherlands, Portugal, Spain, Sweden and the UK. For the purpose of producing international migration estimates between the UK and the rest of the EU15, the UK is excluded from this grouping. However, by convention, this grouping is still referred to as the EU15.

  • EU2

    The EU2 (formerly known as the A2) are the two countries that joined the EU on 1 January 2007: Bulgaria and Romania. EU2 nationals currently have certain restrictions placed on them; in the first 12 months of stay, working Bulgarian and Romanian nationals are generally required to hold an accession worker card or apply for one of two lower-skilled quota schemes. Other Bulgarian and Romanian nationals can apply for a registration certificate, giving proof of a right to live in the UK. These restrictions are due to be lifted on 1 January 2014.

  • EU25

    European Union as constituted between 1 May 2004 and 1 January 2007. The following 25 member states are included: Austria, Belgium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, the Irish Republic, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden and the UK. For the purpose of producing international migration statistics between the UK and the rest of the EU25, the UK is excluded from this grouping. However, by convention, this grouping is still referred to as the EU25.

  • EU27

    European Union as constituted on 1 January 2007. The following twenty seven member states are included: Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, the Irish Republic, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden and the United Kingdom. For the purpose of producing international migration statistics between the UK and the rest of the EU27, the UK is excluded from this grouping. However, by convention, this grouping is still referred to as the EU27.

  • EU8

    The EU8 (formerly known as the A8) are the eight central and eastern European countries that joined the EU on 1 May 2004: Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia and Slovenia. The EU8 does not include the two other countries that joined on that date: Cyprus and Malta. EU8 nationals previously had restrictions on their rights to work and were required to register under the Worker Registration Scheme, but these restrictions were lifted from 1 May 2011.

  • EU accession countries

    The 12 countries that have joined the EU15 since 1 May 2004. These are Bulgaria, Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Romania, Slovakia and Slovenia.

  • European Union (EU)

    The EU consists of 28 countries: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Republic of Ireland, Romania, Slovakia, Slovenia, Spain, Sweden and the United Kingdom. Croatia joined the EU in July 2013 - data with a reference period after that date will include Croatia within the EU grouping.

  • IMPS

    Improving Migration and Population Statistics. The IMPS project aims to improve the accuracy of the Office for National Statistics population estimates and to establish where it is possible to introduce changes to data sources and methods that will improve the quality of the statistics. Further information on this project can be found on the National Statistics website.

  • In-country asylum seekers

    Those asylum seekers who enter the UK and do not apply on arrival at port but apply for asylum while in the UK.

  • IPS

    International Passenger Survey.

  • LFS

    Labour Force Survey - a quarterly household survey run by the Office for National Statistics.

  • Long-term international migrant

    Someone who moves to a country other than that of his or her usual residence for a period of at least a year so that the country of destination effectively becomes his or her new country of usual residence. From the perspective of the country of departure the person will be a long-term emigrant and from that country of arrival the person will be a long-term immigrant (based on UN definition). 

  • Long-Term International Migration (LTIM)

    Long-Term International Migration is produced by combining migration data from the IPS, international migration to and from Northern Ireland, Home Office data on asylum seekers and adjustments for visitor switchers and migrant switchers.

  • Mid-year population estimate

    The estimated resident population on 30 June of the reference year. Estimates are based on the previous mid-year estimate aged on and adjusted for births, deaths, migration and changes in mobile sub-groups in the year to 30 June.

  • Migrant switchers

    Travellers who stated the intention in the IPS to stay in the destination country for more than a year, therefore, counted as migrants but who actually left sooner.

  • National Population Projections

    These are prepared by the Office for National Statistics who, in consultation with the devolved administrations, produce projections for the UK and its four constituent countries. A new set of projections is normally made every second year, based on a full-scale review of the trends affecting the underlying assumptions about fertility, mortality and migration.

  • Non-contacts

    A person counted by the IPS but not interviewed. For example, during peak periods an interviewer may not finish an interview before their next assigned contact has crossed the IPS counting line.

  • Non-response

    Failure to obtain any survey information due to respondent refusal, non-contact or inability to reply.

  • Non-sampling error

    Error attributable to all other sources other than sampling. Non-sampling errors may arise from many different sources. These may include misunderstanding or misreporting by respondents, variations between the way interviewers administer the survey, non-coverage of the population due to an inadequate sampling frame or sample design and errors made when processing the data. 

  • Port asylum seekers

    Those asylum seekers who apply for asylum at UK ports.

  • Response rate

    A measure of the proportion of people contacted who respond to the survey.

  • Sampling error

    The difference between an estimate derived from a random sample and the true population value; the difference being attributable to the fact that only a sample of values was used. That is, sampling error results because not every migrant who enters or leaves the UK is interviewed.

  • Standard error (SE)

    An indication of the accuracy of an estimate and how much a sample estimate is likely to differ from the true value because of random effects.

  • Visitor switchers

    Visitors who enter or leave the UK intending to stay in the destination country for less than a year but who actually stay for a year or longer.

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Contact Details

For statistical enquiries about this topic, please contact:

Migration Statistics Unit

Email: migstatsunit@ons.gsi.gov.uk

Telephone: +44 (0) 13 2944 4097

Office for National Statistics Segensworth Road Fareham PO15 5RR

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