Local area migration indicators QMI

This quality and methodology report contains information on the quality characteristics of the data (including the five European Statistical System dimensions of quality) as well as the methods used to create it.

The information in this report will help you to:

• understand the strengths and limitations of the data

• learn about existing uses and users of the data

• reduce the risk of misusing data

• help you to decide suitable uses for the data

• understand the methods used to create the data

Caution should be taken with all figures when making comparisons between 2020 and previous years' data.

The statistics in this spreadsheet include the period of time before the coronavirus (COVID-19) pandemic in the UK, specifically 2010 to 2019. The latest data is from pre-COVID time (up to March 2020) and from during the pandemic (April to December 2020). The restrictions in place during the 2020 lockdown directly impacted population change at the national and subnational level, affected the volume of international migration to and from the UK, as well as disturbing the collection and processing of demographic data from surveys, registration and administrative sources. More information is given below for each data source used in Local area migration indicators (LAMIS):

• The International Passenger Survey (IPS) was suspended in mid-March 2020. To overcome the lack of data from March to June 2020, measures of long-term international migration (LTIM) were modelled to estimate UK international migration. Further information on this change and its impact can be found in the Migration Statistics Quarterly Report August 2020 and in Using statistical modelling to estimate UK international migration.

• Operational changes were made to the Labour Force Survey (LFS) in 2020. These changes resulted in higher non-response from those who rent their accommodation and those with a non-UK country of birth or non-British nationality, leaving them less well represented in the achieved sample. The LFS weighting methodology was also using population projections that predated the pandemic and were therefore not able to reflect the demographic and structural impact the UK has faced. In July 2021 the LFS was reweighted for estimates from January 2020 onwards, as detailed in Coronavirus and its impact on the Labour Force Survey. This process has made the estimates for UK, EU and non-EU more robust, but there remains a high level of uncertainty for data below this level. Therefore the more detailed numbers should not be compared against previous years. Further information on the method used to reweight the LFS is available in the Labour Force Survey weighting methodology.

• National Insurance Number (NINo) operations were paused for most applicants from mid-March 2020, with EU nationals particularly affected by the closure of face-to face-services. Postal services, used by non-EU nationals, were reinstated in June 2020.

• The completeness of figures for GP registrations for mid-2019 to mid-2020 may have been affected by the pandemic, if people were unable to register with a GP during the period of lockdown. Internal migration estimates may also have been affected as GP registrations are the main data source for this indicator. Further details on this and the impact of the pandemic on the mid-year population estimates are available in the mid-year population estimates QMI.

• Each indicator in the Local area migration indicators provide different measures; together these can provide a more complete picture of migration in local areas.

• The indicators used are from various data sources, which use different definitions and count different types of migration; this should be taken into consideration when comparing the data.

• The majority of the latest indicator tables contain complete information for the years 2011 to 2020.

• Short-Term International Migration statistics have not been updated since the 2019 release of the Local area migration indicators (so data from mid-2016 to mid-2017 remain provisional). Further information can be found in Short-term international migration annual report: year ending June 2019

• Births to Non-UK Born Mothers have not been updated, as data for England and Wales is not yet available. The latest release can be found on the ONS website page Parents' Country of Birth.

• The migration data, migrant General Practitioner (GP) registrations and National Insurance number (NINo) allocations to overseas nationals can be used for indications of the "flows" of migrants into and out of geographical areas.

• The non-UK born population, the non-British national population and the live births to non-UK born mothers data give an indication of the "stock" of migrants living in the UK. Figures are shown for 374 local and unitary authorities (331 in England and Wales, 32 in Scotland and 11 (known as LGD2014) in Northern Ireland), 30 counties (not including inner and outer London), 9 regions and the 4 countries of the UK.

Overview

The Local area migration indicators are an annual publication and contain:

• Long-Term International and internal Migration statistics

• Short-Term International Migration statistics

• non-UK born population statistics

• non-British nationality population statistics

• migrant General Practitioner (GP) registration counts

• migrant National Insurance number (NINo) allocations

• live births to non-UK born mothers statistics

The Local area migration indicators are an Excel spreadsheet, which allows access for the user's own analysis to the underlying data containing all indicators for all available geographies. Most of the data included are published elsewhere; this product adds value by bringing migration-related statistics together in one place to enable comparisons to be made more easily.

Uses and users

The Office for National Statistics (ONS) is transforming the way we produce population and migration statistics to better meet the needs of our users. In June 2021 ONS published its latest update on our population and migration statistics transformation journey. This followed a research engagement report published in January 2019 that also sought feedback on our future plans. The feedback showed that users:

• welcome the move to put administrative data at the core of our statistics

• would like the option to compare different sources of data

• have a desire for more detailed local-level data

• would like the ability to manipulate the data to a greater extent and the option to use a data explorer to run their own cross-tabulations

Previous consultations

• 11 November 2016 to 23 December 2016: Consultation on international migration statistical outputs

• 1 November 2010 to 24 December 2010:ONS work programme consultation

This report provides a range of information that describes the quality of the output and details any points that should be noted when using the output.

We have developed Guidelines for Measuring Statistical Quality; these are based upon the five European Statistical System (ESS) quality dimensions. This report addresses these quality dimensions and other important quality characteristics, which are:

• relevance

• timeliness and punctuality

• coherence and comparability

• accuracy

• output quality trade-offs

• assessment of user needs and perceptions

• accessibility and clarity

More information is provided about these quality dimensions in the following sections.

Relevance

(The degree to which the statistical outputs meet users' needs.)

The Local area migration indicators provide migration-related information for local areas. All of the data included are also published elsewhere - the added value of this product is that migration-related statistics are brought together in one place, enabling comparisons to be made more easily. Each indicator provides different measures, which together can provide a more complete picture of migration in local areas.

The indicators include migrant stock estimates of non-UK born and non-British nationals. These are not estimates of recent migration into an area, but they are associated with migration flows. For example, areas with high proportions of the population born outside of the UK are likely to also have high levels of migration. For more information on the difference between migration flows and a migrant stock, see the international migration first time user guide.

The indicators are in an Excel spreadsheet, which allows users to compare different indicators for all available geographies. It should be noted that not all indicators are directly comparable (for example, some are flows (movement into and out of an area) and some are stocks (the resident population of an area)). The geographic coverage also varies.

The following data are included.

Migration flows

Long-Term International and internal Migration estimates at local authority level for England, Wales, Scotland and Northern Ireland are produced by the Office for National Statistics (ONS), National Records of Scotland (NRS) and Northern Ireland Statistics and Research Agency (NISRA) for the purpose of producing population estimates. The data are presented as follows:

• long-term international immigration and emigration - representing the number of people arriving in the UK or leaving the UK for a period of at least 12 months

• internal in-migration and out-migration - an estimate of migration within the UK (cross-border flows between each of the constituent countries, as well as migration between local authorities)

Short-Term International Migration estimates at local authority level for England and Wales are produced by the ONS. The data are presented as follows:

• short-term international immigration - an estimate of the number of short-term visits to England and Wales, satisfying the United Nations (UN) definition (3 to 12 months for work or study)

The International Passenger Survey (IPS) carried out by the ONS is the primary source of Short-Term International Migration data. It is used to create a single estimate of the short-term migration inflow to England and Wales, which is then distributed to local authority level using the following administrative data sources:

• grants of extensions of Leave to Remain from Home Office

• Certificates of Sponsorship (CoS) from Home Office

• Confirmation of Acceptance for Studies (CAS) from Home Office

• Migrant Workers Scan (MWS) from Department for Work and Pensions (DWP)

• Student Record from Higher Education Statistics Agency (HESA)

• Individualised Learner Record from the former Department for Business Innovation and Skills (BIS)

• Lifelong Learning Wales Record from Welsh Government (WG)

Non-UK born population and non-British nationality population

Estimates of the non-UK born and non-British nationality populations covering the UK are estimated by the ONS using the Annual Population Survey (APS). The APS is the Labour Force Survey (LFS) plus various sample "boosts". The APS has the largest coverage of any ONS household survey.

The survey covers private households but most communal establishments are excluded. Students living in halls of residence will be captured by proxy, but only if they have a UK-resident parent. This means most international students living in halls of residence will not be identified in the APS.

In July 2021 the LFS was reweighted for estimates from January 2020 onwards, as detailed in Coronavirus and its impact on the Labour Force Survey.

In March 2015, the APS was reweighted using revised UK and subnational population estimates consistent with the 2011 Census. In July 2015, we published reweighted estimates of the UK population by country of birth and nationality for calendar years 2004 to 2013. A comparisons paper has been written looking at the differences between the old estimates and the reweighted estimates. The reweighting caused the estimate of the population of the UK to increase by 538,000 between 2004 and 2013.

Migrant General Practitioner (GP) registrations

For England and Wales, each year, the ONS receives a demographic snapshot of Patient Register (PR) data held by NHS Digital. Flag 4s are codes within the PR data that indicate that an individual's last address (as registered with an NHS GP) was overseas.

For Northern Ireland, each year, Northern Ireland Statistics and Research Agency (NISRA) receives individual Code 4 (NISRA Flag 4 equivalent) registrations by date of registration from the Health and Social Care (HSC) Business Services Organisation (BSO).

Migrant National Insurance number allocations

Statistics for National Insurance number (NINo) allocations to adult overseas nationals are provided by the Department for Work and Pensions (DWP). This records non-UK nationals who are legally employed (including the self-employed and students working part-time) and those wanting to claim benefits or tax credits.

Live births to non-UK born mothers

Birth statistics present data on births that occur and are then registered in England, Wales, Scotland and Northern Ireland. Statistics are based on information collected at birth registration from the General Register Office (GRO), National Records of Scotland and Northern Ireland Statistics and Research Agency.

Annual birth outputs represent births occurring in England, Wales, Scotland and Northern Ireland in a given year and are provided by the ONS.

Accuracy and reliability

Administrative sources are not primarily designed to measure population or migration. For example, migrant General Practitioner (GP) registrations by local authority and National Insurance number (NINo) counts are all derived from administrative data sources. The coverage of international migrants joining an administrative source will depend on the purpose of the particular administrative system and will invariably differ between sources. Please see A summary of administrative data sources and their potential to inform statistics on migration and population (PDF, 72KB) for further details on their use.

Migration flows

The mid-year population estimates include both internal and Long-Term International Migration as components of change. There are different factors affecting accuracy for each component since each is produced using different sources and methods. The following guides provide further information on factors affecting accuracy of migration data:

• Population estimates for the UK, mid-2020: methods guide

• Mid-year population estimates QMI

• Long-Term International Migration estimates methodology

• International migration methodology

• there is no formal registration of internal migration moves so within England and Wales estimates are derived from NHS data, on the basis that most people register with a new GP when they move; data from the Higher Education Statistics Agency (HESA) are also used to improve estimation of moves for and after study; this combination is considered to provide a good proxy for actual move, full information on the methods is in the Internal migration estimates QMI

• Mid-year population estimates for Scotland: methodology guide 2020 (PDF, 840KB)

• Methodology paper: mid-year population estimates for Northern Ireland (PDF, 204KB)

Short-Term International Migration methodology can also be accessed for further information:

• Short-Term International Migration methodology - local authorities estimates

• Short-Term International Migration methodology - national estimates

• Short-Term International Migration (STIM) estimates for local authorities QMI

Non-UK born population and non-British nationality population

The Annual Population Survey (APS) is used to estimate the household population of the UK by country of birth and nationality. Confidence intervals are published alongside these estimates and detail how accurate the estimate is by giving a range of values that the actual figure may fall between.

The APS Labour Force Survey (LFS) plus various local area sample "boosts" to increase the sample size) ensures minimum representation of each area of the UK in the sample. Boost interviews are conducted throughout the year and included in the APS dataset in the quarter in which they are conducted. Respondents in the LFS boost are interviewed only once a year, for four consecutive years. Only in the main LFS do interviews take place each quarter.

Each quarter's LFS sample of 40,000 households is made up from five "waves", each of approximately 8,000 households. Each wave is interviewed in five successive quarters, such that in any one quarter, one wave will be receiving their first interview, one wave their second and so on, with one wave receiving their fifth and final interview. Thus, there is an 80% overlap in the samples for each successive quarter and the sample is completely different after six quarters.

The APS combines results from the LFS and the English, Welsh and Scottish Labour Force Survey sample boosts. During 2004 and 2005, the APS also included an additional sample boost for England. Northern Ireland does not have an additional boost. More robust estimates are available by using the APS than from the main LFS. APS datasets are produced quarterly with each dataset containing 12 months of data. There are approximately 320,000 persons per dataset. For more information please see the Quality and Methodology Information (QMI) for the APS.

The population figures used to weight the APS are adjusted to cover the same private household population that the survey covers and so differ from the mid-year population estimates. Further information can be found in the LFS user guide.

Migrant GP registrations

Migrant GP registration data are based on administrative data sources, which are not designed for capturing information directly about migrants. However, Flag 4 counts for England and Wales, and Code 4 counts for Northern Ireland, provide an indication of recent international immigration to local authority areas and can be used to derive in-migration to local authorities. There are a number of reasons why there may be differences with actual levels of immigration.

GP registration is not compulsory and some migrants will only register with a GP if and when they require medical attention.

Registration patterns vary by sex and age group. In particular, young adult males are known to be less likely to register than other groups, thus limiting the usefulness of Flag 4s as an indicator of migration. There may also be a lag between the migration event and the eventual GP registration. We have undertaken research on the time lag differences between groups.

A person may register with a GP if they are staying in the UK for at least three months and so Flag 4s may include some short-term migrants, which are not included in the population estimates (in Northern Ireland the migrants have to be staying the greater part of a year to qualify for registering with a GP, so have to be here at least six months and a day).

Flag 4 records may not be retained on patient register records through the person's subsequent migration within the UK. When an immigrant subsequently moves internally within the UK and re-registers with a second GP, the Flag 4 record is not retained as the individual's last residence is now within the UK. If this internal migration happens within a year of the migrant arriving in the UK, the Flag 4 will not be recorded on the extract provided to us. However, Northern Ireland still hold data for all migrants; because of the land border with the rest of Ireland. Business Services Organisation (BSO) assess the right to entitlement for all patients registering, even if they are migrants registered elsewhere in the UK first.

Flag 4s are added where the address of previous residence is outside the UK. This may be as a result of a short residence outside the UK that does not fit with statistical definitions of migration - a patient may be a UK resident, move abroad for a relatively short period and then return to the UK.

Patients in Northern Ireland who are here on time-limiting visas are contacted three months before their visa is due to expire, informing them that if a new visa is not provided they will be deducted. If they provide a copy of their new visa their registration is extended, otherwise they are deducted from the GP's register.

Northern Ireland also registers a small number of cross-border workers as Code 4s as, if a person lives in the south of Ireland and works in the north then they are entitled to NHS treatment.

The Coherence and Comparability section details issues regarding comparability with other sources.

National Insurance number allocations to overseas nationals

A National Insurance number (NINo) is required for anyone wanting to work legally or claim benefits in the UK. Therefore, NINo allocations to foreign nationals provide an indicator of recent migration to the UK. There is no minimum stay requirement to register for a NINo, so NINo data contain both short- and long-term migrants.

Migrant groups not covered by migrant NINo data include child migrants (those under 15 years 9 months), migrants who work illegally and adult migrants who neither work nor claim benefits (often students or spouses of employed migrants). Asylum seekers are also generally excluded as NINo applications are not usually approved until rights to reside in the UK have been granted.

Data are released quarterly with a lead time of three months, for example, data released in August 2017 cover NINo registrations to June 2017.

Live births to non-UK born mothers

Birth statistics are based on registrations provided by the General Register Office (GRO), National Records of Scotland and Northern Ireland Statistics and Research Agency. These data represent the legal record, making it the best and most complete data source.

As part of the birth registration process, the registrar asks the informant to verify that all data entered are accurate. The registrar is then able to correct any errors.

Information supplied at birth registration is generally believed to be correct, since wilfully supplying false information may render the informant liable to prosecution for perjury.

When the Office for National Statistics (ONS) receives birth registrations, a number of checks are carried out on records to ensure that they are valid. Any birth records that appear questionable are raised with GRO on a monthly basis for further investigation.

Further information can be found in the England and Wales Births user guide and the England and Wales Births Quality and Methodology Information reports.

Coherence and comparability

(Coherence is the degree to which data derived from different sources or methods, but referring to the same topic, are similar. Comparability is the degree to which data can be compared over time and domain, for example, geographic level).

There are other additional data sources and databases available that may provide information on movements into the UK. These sources may serve as further references on the topic.

The indicators used are from various data sources, which use different definitions and count different types of migration. Care needs to be taken when comparing the data. The migration data, migrant GP registrations and NINo allocations to overseas nationals can be used for indications of the "flows" of migrants into and out of geographical areas. The non-UK born population, the non-British nationality population and live births to non-UK born mothers data give an indication of the stock of migrants living in the UK.

There are definitional differences between the data sources. For example, migrant GP registrations, NINo allocation statistics and live births data are based on administrative data sources and the coverage and measurement of international migrants will relate to what is required for administrative purposes. For instance, migrant GP registrations cover nationals of all countries.

The methodology that is used to update population estimates accounts for flows of Long-Term International Migration; whereas the administrative sources may include both short- and long-term migrants.

Migration flows

Migration flow figures are for mid-year to mid-year periods. Therefore, reference periods are not directly comparable with other available indicators available on a calendar year basis.

Migration flow figures incorporate both inflows and outflows, and are therefore not directly comparable with administrative data sources, which record inflows only.

The method for producing short-term international immigration estimates at local authority level is based on a similar methodology for producing long-term immigration estimates at local authority level. However, adding together Long-Term International Migration (LTIM) and Short-Term International Migration (STIM) estimates does not provide a reliable measure of all immigration and emigration to the UK within a specific time-period:

• short-term immigration flows are based on journeys to England and Wales, not the movement of people into and out of the UK, and have methodological differences from LTIM flows

• it is possible for someone to be both a long-term and short-term migrant in a given period

• STIM estimates are based on actual migration behaviours whereas LTIM uses migrants' intentions to infer their length of stay

Although they cannot be added together to provide one single measure of international migration, LTIM and STIM estimates of immigration and emigration should be considered alongside and in the context of each other. These estimates represent different people migrating for different reasons but they can help to provide an overall picture of international migration.

Non-UK born population and non-British nationality population

Estimates of non-British citizens and non-UK born population from the Annual Population Survey (APS) provide an indication of migration stocks, therefore these indicators are not directly comparable with indicators of migration flows such as population turnover or National Insurance number (NINo) registrations.

Migrant General Practitioner (GP) registrations

Migrant GP registration statistics provide an indication of recent international in-migrants to local authority areas; however, because of the following definitional differences, the figures are not directly comparable with other indicators of migration such as estimates of long-term international migration.

Migrant GP registration statistics are derived from administrative systems that are not designed primarily for statistical purposes. For more information on internal migration estimates please see the Internal migration estimates Quality and Methodology Information report.

Flag 4 records may not be retained on patient register records through the person's subsequent migration within the UK. The patient register is a "snapshot" taken annually. When an in-migrant subsequently moves internally within the UK and re-registers with a second GP, the Flag 4 demarcation is not retained as the individual's last residence is now within the UK. If this internal migration occurs within the year of in-migration, that is, before the next mid-year snapshot, the in-migration will not be recorded.

However, Northern Ireland still hold data for all migrants; because of the land border with the rest of Ireland, Business Services Organisation (BSO) assess the right to entitlement for all patients registering, even if they are migrants registered elsewhere in the UK first.

GP registration is not compulsory. Some migrants will only register with a GP if, and when, they require medical attention. There may also be a lag between the migration event and the eventual GP registration.

The completeness of the data depends on all patients registering with an NHS GP when they move to England and Wales or Northern Ireland. However, it is known that registration patterns vary by sex and age group. Therefore, the usefulness of the data as an indicator of migration is limited by some groups being less likely to register with a GP than others. For example, as mentioned, young adult males (who make up a large proportion of migrants) are less likely to register with a GP than other groups.

A person may register with a GP if they are staying in the UK for at least three months and so Flag 4s may include some short-term migrants, which are not included in the population estimates (in Northern Ireland the migrants have to be staying the greater part of a year to qualify for registering with a GP, so have to be here at least six months and a day).

Flag 4s are added where the address of previous residence is outside the UK. This may be as a result of a short residence outside the UK that does not fit with statistical definitions of migration - a patient may be a UK resident, move abroad for a relatively short period and then return to the UK.

National Insurance number allocations to overseas nationals

There is no minimum stay requirement to register for a National Insurance number (NINo). Coverage is also limited to the population eligible to work or claim benefits. This indicator is therefore not directly comparable with other migration indicators.

Concepts and definitions (including list of changes to definitions)

(Concepts and definitions describe the legislation governing the output and a description of the classifications used in the output.)

Migration flows

For Long-Term International Migration, the UN-recommended definition is used:

"A long-term international migrant is defined as a person 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."

Inflow

Long-term: persons arriving or returning from abroad to take up residence in a country for a period of at least 12 months.

Outflow

Long-term: persons leaving their country of usual residence to take up residence in another country for a period of at least 12 months.

Internal migration

At the national level, this component estimates migration between each of the UK constituent countries. At subnational level, estimates of flows between each local authority and other local authorities in the UK are also included. Since internal moves are not recorded formally, information obtained from the NHS Central Register (NHSCR) and General Practitioners (GP) patient registers is used as a proxy.

For England and Wales estimates, these data are considered to be a good proxy for internal migration as, when moving, most patients will eventually register with a new GP. Complete information on all moves at former health authority level from the NHSCR are combined with more geographically detailed data from the patient registers to produce the migration estimates by local authority used in the population estimates.

Short-term migration flows

The UN definition of short-term international migration is:

"A person who moves to a country other than that of his or her usual residence for a period of at least three months but less than a year (12 months) except in cases where the movement to that country is for purposes of recreation, holiday, visits to friends and relatives, business, medical treatment or religious pilgrimage."

Non-UK born population and non-British nationality population

The estimated resident population of an area includes all people who usually live there, whatever their nationality. Members of UK and non-UK armed forces stationed in the UK are included and UK forces stationed outside the UK are excluded. Students are taken to be resident at their term-time address.

Resident population

The estimated resident population of an area includes all people who usually live there, whatever their country of birth or nationality. Members of UK and non-UK armed forces stationed in the UK are included and UK forces stationed outside the UK are excluded. Students are taken to be resident at their term-time address.

Annual Population Survey (APS)

The APS combines the results from the Labour Force Survey (LFS) Waves 1 and 5 with the English, Welsh and Scottish Local Labour Force Survey (LLFS). The sample size is 122,000 households (or 320,000 respondents) on the annual APS dataset, compared with 40,000 households (or 120,000 respondents) on the quarterly LFS dataset. For 2004 and 2005, the APS also comprised a boost sample (APS(B)) of 65,000 households. However, APS(B) ceased at the end of December 2005.

Migrant General Practitioners (GP) registrations

Flag 4 records are provided to the Office for National Statistics (ONS) from the Patient Register (PR) data provided by NHS Digital. Flag 4s are codes within the PR data that indicate that someone has registered with a GP in England and Wales and was previously living overseas. A Flag 4 may be generated when an individual registers with an NHS GP if:

• an individual was born outside the UK and enters England and Wales for the first time and registers with a NHS GP

• the previous address of an individual is reported as outside of the UK

Code 4 records are provided to Northern Ireland Statistics and Research Agency (NISRA) by the Health and Social Care (HSC) Business Services Organisation. Code 4s relate to individual registrations with a GP in Northern Ireland from persons who were previously living overseas. A Code 4 may be generated when an individual registers with a NHS GP if:

• an individual was born outside the UK and enters Northern Ireland for the first time and registers with a NHS GP

• an individual's registration may also generate a Code 4 if their previous address is outside the UK and they have been living outside the UK for more than one year

Live births to non-UK born mothers

Birth statistics for England and Wales are based on the details collected when births are registered. By law, births should be registered within 42 days. The country of birth of parents for children born has been recorded at birth registration since April 1969.

The area refers to the area of usual residence of the mother.

The details for country of birth groupings can be found in the Parents' country of birth package on the country code listings tab. Birthplace does not necessarily equate with ethnic group or nationality. Not all women born outside the UK will be recent in-migrants. Similarly, the UK-born will include the children of earlier in-migrants (the second and third generation). A fuller discussion of this subject can be found in a Population Trends article.

Further information on terms and definitions is also available.

Output quality

The different data sources that are used to compile the Local area migration indicators have various levels of accuracy and timeliness.

As mentioned previously, the indicators used are from various data sources, which use different definitions and count different types of migration. Care needs to be taken when comparing the data, although the data can be used to compare different indicators as well as different geographical areas.

Geography (including list of changes to boundaries)

Geographical coverage varies across indicators, but generally estimates are available at a national level for England, Wales, Scotland and Northern Ireland and for regions, counties, unitary authorities and local authorities within England and Wales; council areas within Scotland; and local government districts within Northern Ireland.

Specific geographical coverage by indicator are:

• Long-Term International Migration flows - England, Wales, Scotland and Northern Ireland

• Short-Term International Migration flows - England and Wales

• non-UK born and non-British - England, Wales and Scotland

• migrant GP data - England, Wales and Northern Ireland

• NINo data - England, Wales, Scotland and Northern Ireland

• live births to non-UK born mothers - England, Wales, Scotland and Northern Ireland

Boundary changes may have occurred over time. For details of historic boundaries, refer to ONS administrative geography pages.

Accessibility and clarity

Our recommended format for accessible content is a combination of HTML webpages for narrative, charts and graphs, with data being provided in usable formats such as CSV and Excel. In some instances other software may be used, or may be available on request. Available formats for content published on our website but not produced by us, or referenced on our website but stored elsewhere, may vary. For further information please refer to the contact details at the beginning of this report.

For information regarding conditions of access to data, please refer to the following links:

• Terms and conditions (for data on the website)

• Accessibility

Timeliness and punctuality

The indicators were updated quarterly, with the most up-to-date data available, until August 2012. Following a consultation exercise, it was agreed to move the indicators to an annual publication.

For more details on related releases, the GOV.UK release calendar provides 12 months advance notice of release dates. If there are any changes to the pre-announced release schedule, public attention will be drawn to the change and the reasons for the change will be explained fully at the same time, as set out in the Code of Practice for Statistics.

The indicators  are revised on an annual basis. Last revised 17 September 2021.

How we collect the data

The Local area migration indicators are a compilation of various data sources. For more information on the methodology of each of the individual sources, see the following links:

• migration flows are compiled by the Office for National Statistics (ONS), National Records of Scotland (NRS) and Northern Ireland Statistics and Research Agency (NISRA), please see Methodology: An overview of population and migration statistics

• non-UK born and non-British nationality are compiled by the ONS, please see Methodology: An overview of population and migration statistics

• Short-Term International Migration is compiled by the ONS, please see Short-Term International Migration methodology

• migrant GP registrations by local authority are compiled by the ONS and NISRA using Patient Register (PR) data held by NHS Digital

• National Insurance number allocations are published by Department for Work and Pensions on the Stat-Xplore website

• live births to non-UK born mothers data are collected on births that occur and are then registered in England and Wales; for more detailed information on the production of birth statistics, see the Methodology: User guide to birth statistics

Useful links and contact details

Migration flows

Non-UK born population and non-British nationality population

Migrant GP registrations

For any queries regarding Flag 4 data please email: pop.info@ons.gov.uk.

National Insurance number allocations to overseas nationals

Statistics on National Insurance number allocations

Live births to non-UK born mothers