*Prepared by Laura Cheatham
NOTE: The designations employed in this document do not imply the expression of any opinion whatsoever on the part
of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area or of its
authorities, or concerning the delimitation of its frontiers or boundaries.
Economic Commission for Europe
Conference of European Statisticians
Group of Experts on Migration Statistics
Geneva, Switzerland, 7−8 May 2024
Item 7 of the provisional agenda
Results on migration from the 2020 population census round
Using Census 2021 to understand international
migration in England and Wales from 2012 to
2023
Note by: Office for National Statistics
Abstract
Censuses provide an important data source for information on international migrants
resident in England and Wales. In 2021, we collected a range of information on
international migrants, including their country of birth, passports, year of arrival and
intention to stay. This allowed us to identify both long-term and short-term migrants and
produce a range of analysis on their economic and social characteristics compared to the
wider population, as well as focusing on specific groups of interest such as international
students and dual citizens.
The census also provided an important source for assessing the quality of our
international migration estimates across the decade from 2012 to 2021. This informed
revisions to our estimates of British nationals over the previous decade and helped refine
our new methods for estimating international migration using administrative data.
Therefore, providing confidence in our administrative-based migration estimates. This
also informed how we continue to use administrative data to estimate migration in the
future.
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Distr.: General
29 April 2024
English
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I. Introduction
1. In England and Wales, the census is undertaken by the Office for National Statistics (ONS)
and in the past has been every 10 years. It collects information on all people and households
to build a detailed snapshot of society. The most recent census was held on 21 March 2021.
2. Censuses for Scotland and Northern Ireland are run by National Records of Scotland and the
Northern Ireland Statistics and Research Agency respectively.
3. The range of information collected by Census 2021 provides insight into both the number of
international migrants living in England and Wales and their characteristics. It also provides
a unique opportunity to assess the quality of new admin-based migration estimates and
refine methods where necessary, as well as informing revisions required to migration
estimates produced over the previous decade.
II. What Census 2021 told us about international migration and the
characteristics of migrants.
A. Introduction
4. The outputs from Census 2021 for England and Wales were released in 2022. These
included an international migration topic summary article (ONS, 2022) providing univariate
data and supporting information on country of birth, passports held, address one year before
the census and year of arrival.
5. Census 2021 showed that:
i. one in six usual residents of England and Wales were born outside the UK, an
increase of 2.5 million since 2011, from 7.5 million (13.4%) to 10 million (16.8%),
ii. 5.9 million usual residents (9.9%) held a non-UK passport,
iii. 545,000 usual residents (0.9% of the population) had an address outside the UK one
year before the census, down 11.0% from 612,000 (1.1%) in 2011.
6. A series of in-depth articles have subsequently been published based on multivariate census
data. This more detailed data allows further analysis of the characteristics of different groups
of international migrants, such as those staying long-term and short-term, international
students and dual citizens.
B. Long-term international migration
7. Long-term international migrants in Census 2021 analysis were defined in line with the UN
definition of a person who has moved to a country other than that of their usual residence for
a period of at least 12 months, using two primary approaches:
i. those born outside the UK, who therefore have migrated to the UK at some point in
the past,
ii. those who hold a non-UK passport (used to indicate a person's nationality).
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8. Initial analysis of long-term international migration (ONS, 2023a) looked at the geographical
distribution of long-term international migrants at regional and local level; economic status
of migrants, such as employment rates and industries of employment; and the most common
non-UK countries of birth and their passports held. A further article exploring the social
characteristics of long-term international migrants (ONS, 2023b) covered topics such as the
age, sex, housing, family, language, health, qualifications, religion, national identity and
ethnicity of the non-UK-born population.
9. Between 2011 and 2021, the proportion of non-UK-born residents increased across all
regions of England, with London (positive 3.9 percentage points), East of England (positive
3.9 percentage points) and the East Midlands (positive 3.8 percentage points) showing the
largest increases.
10. People born in Romania and Bulgaria (EU2) and EU8 countries had the highest employment
rates in 2021. The most common industry of employment for EU-born migrants was
wholesale and retail and repair of motor vehicles (15.8%), while for non-EU-born it was
human health and social work (19.5%).
11. India, Pakistan and Bangladesh were the top three countries of birth with the highest number
of UK passport holders. Overall, EU-born residents are less likely to hold a UK passport.
12. Those who had arrived in the year prior to Census 2021, were more likely to be
economically inactive students; have been born in the Middle East and Asia (reflecting the
large international student population from this area); and have a younger age profile than
for all non-UK-born residents.
13. Most non-UK-born usual residents had high levels of English proficiency; 87% of recent
arrivals between 2011 and 2021 reported speaking English very well or well, or having it as
a main language.
14. The proportion of non-UK-born residents (43%) who lived in owner-occupied
accommodation was lower than UK-born (67%); however, 57% of non-UK-born who had
been in the UK for at least 10 years lived in owner-occupied accommodation.
15. Those who arrived in the UK earlier were more likely to describe their national identity as
being one from the UK only. For example, 81% of non-EU-born residents who arrived
between 1981 and 1990 reported an identity from the UK only, compared with 20% who
arrived between 2011 and 2021.
C. Short-term international migration
16. Short-term international migrants in Census 2021 analysis were defined as those who met all
of the following criteria:
i. born outside the UK,
ii. arrived within a year before census day,
iii. intended to stay for a period of between 3 and 12 months (those intending to stay for
less than 3 months were not asked to answer Census 2021).
17. Analysis of this group (ONS, 2023c) covered their country of birth, economic activity, and
industry as well as other characteristics such as age, sex and geographical distribution.
18. There were 136,000 non-UK-born short-term residents recorded by Census 2021; 45% were
men and 55% were women, while a third (33%) were aged between 20 and 24 years.
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19. Compared with the 2011 Census, the proportion of EU-born short-term residents fell from
35% to 25% in 2021, while the proportion of non-EU-born residents rose from 65% to 75%.
20. Almost a third of non-UK-born short-term residents lived in London (29%).
21. China was the most common country of birth for non-UK-born short-term residents (21%)
followed by India (10%) and Romania (5%).
22. Of non-UK-born short-term residents, 42% were economically inactive students, with 45%
of this population born in China.
D. International students
23. For the purpose of analysing Census 2021 data, international students were defined as those
who met all of the following criteria:
i. in full-time education,
ii. non-UK-born,
iii. non-UK passport holder,
iv. aged 17 years or over upon most recent arrival in the UK,
v. aged 18 years or over on Census Day.
24. The country of birth, age, sex, employment status, industry, housing type and language
spoken of international students was analysed in the article ‘The international student
population in England and Wales: Census 2021’ (ONS, 2023d).
25. There were 373,600 non-UK-born, non-UK passport holding international students in
England and Wales at the time of Census 2021.
26. India (11.6%), China (11.2%), Romania (9.5%) and Nigeria (5.3%) were the top four
individual countries of birth of international students.
27. A third of the international student population was in London (33.9%).
28. One in three international students were in employment; Eastern European countries had the
highest proportions in employment alongside studying (Romania, 73.9%; Bulgaria, 62.3%;
Poland, 56.7%, and Lithuania, 56.0%).
29. Of the international students whose preferred main language was not English (239,000,
64.0%), 59.3% and 35.5% reported being able to speak English very well and well
respectively.
E. Dual citizens
30. Analysis of dual citizens in Census 2021 data (ONS, 2023e) uses data on passports held, as
direct information on citizenship was not collected. It is possible to use this to look at both
international migrants who have or have not gained a UK passport, as well as UK-born
citizens who may also hold non-UK passports.
31. In 2021, across England and Wales, 1.26 million usual residents held multiple passports
(2.1%), up from 612,000 (1.1%) in 2011.
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32. Overall, 1.2% of UK-born residents were UK-other dual citizens (587,600), rising from
0.5% in 2011 (231,600); for non-UK-born residents, 6.5% were UK-other dual citizens in
2021 (648,700), rising from 5.1% in 2011 (381,200).
33. The proportion of people holding both UK and EU passports increased by five times for UK-
born residents and threefold for non-UK-born residents since 2011. UK-Irish passports also
saw a sixfold increase for UK-born residents.
34. The majority of UK-other dual citizens identified with a UK national identity, and this
increased notably the longer people had lived in the UK.
III. Using Census 2021 to assure estimates of international migration
over the last decade
F. Introduction
35. Census-based mid-year estimates are the official mid-2021 population estimates, these are
based on Census 2021 for England and Wales.
36. The 2021 rolled-forward mid-year estimates use the population estimate from the previous
reference date (2020 in this instance) as the starting point for estimating the population at the
current reference date. The previous population estimate is aged on and data on births,
deaths and migration are used to reflect population change during the reference period. This
process has been repeated each year since the last reconciliation and rebasing exercise took
place with the 2011 Census.
37. The 2021 rolled-forward mid-year estimates (MYE) for England and Wales were 268,500
higher than Census 2021-based MYE.
38. The main components that could contribute to this difference for England and Wales are:
i. births,
ii. deaths,
iii. net migration,
iv. variability in Census 2021 estimates,
v. cross border flows between England and Wales and the other countries of the UK,
vi. the 2011 Census population base
39. The registration of births and deaths that occur in the UK is compulsory, and the data quality
is high overall, any attribution of differences to these causes will be relatively small. There is
no evidence to show that there is any substantial error in the cross-border flows to and from
Scotland and Northern Ireland.
40. At the England and Wales level, an overestimation of net international migration is likely to
be the main contributor to the difference seen between the 2021 rolled forward MYE and the
Census 2021-based MYE. For the majority of the decade this component was produced
using survey-based estimates.
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G. Admin-based migration estimates
41. International migration statistics for the UK have historically been measured using the
International Passenger Survey (IPS), a face-to-face survey at most air and sea-ports in the
UK. The IPS measures a migrant’s intention to stay in or depart from the UK long-term (for
12 months or more). Previous analysis has demonstrated that certain groups of migrants
have a higher degree of uncertainty in their intentions to move to and from the UK (ONS,
2019). Therefore, it has long-been acknowledged that the reliance on the IPS for migration
statistics stretched it beyond its original purpose.
42. These findings led the ONS to launch a transformation programme in 2019, focusing on
measuring migration using administrative data first and foremost.
43. In 2020 when the coronavirus (COVID-19) pandemic stopped international travel, the IPS
was also suspended. In response, we accelerated our approach for transforming migration
statistics using administrative data supported by statistical modelling.
44. Although the IPS resumed operation in January 2021, we continue to focus on using
administrative data to estimate international migration. Its migrant focused shifts, aimed at
specifically boosting the number of migrant contacts, are no longer being run and therefore
recent IPS data is even more limited than it was previously. .
45. Since May 2022 we have produced estimates of international migration using administrative
data (UNECE, 2022). Our research since then has focused on replicating these methods to
estimate international migration using administrative data for the intercensal period between
2012 and 2021.
H. Revised admin-based migration estimates from 2012 to 2021
46. ONS published an article in 2023 (ONS, 2023f) that provided information on the methods
used to update our long-term international migration estimates to and from the UK,
including comparisons with other data sources. This demonstrated confidence in these
updates figures and provided a better understanding about migration patterns over the last
decade.
1. British Nationals
47. Using administrative data to measure international migration of British nationals is more
difficult as there are many reasons they could stop interacting with administrative systems
but remain living in the UK, for example to study.
48. Therefore migration estimates for British Nationals are still predominantly based on the
International Passenger Survey (IPS).
49. However, census data provides an alternative source for estimating international migration
of British nationals to and from England and Wales over the decade from 2011 to 2021, by
looking at changes in the UK-born population and adjusting this to estimate migration of
British nationals.
50. Change in the UK-born population in England and Wales between the 2011 Census and
Census 2021 is the result of:
i. Births
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ii. Deaths
iii. cross-border migration to Scotland and Northern Ireland
iv. international migration
51. This analysis has suggested that there was net migration of British nationals from the UK of
negative 787,000 between 2011 and 2021.
52. The IPS estimated that 317,000 more people left the UK than arrived over the same period.
This was considerably lower than the level of migration indicated by evidence from the
census.
53. Therefore, based on this evidence from the census we changed our estimates of net
migration of British nationals by approximately negative 471,000 over the decade compared
with our previous best estimates. As the IPS consistently showed British nationals left the
UK over the decade, we believe it is more likely to be caused by missed emigration and have
attributed most of this adjustment to emigration.
2. EU Nationals
54. We use interactions with the tax and benefits system to estimate international migration of
EU nationals over the decade.
55. These show consistently higher levels of net migration than our previous IPS based
estimates, however evidence suggested that the IPS was underestimating the migration of
EU nationals who had more uncertain intentions to move to or from the UK.
56. Our initial research using the tax and benefits data included 4 arrival categories. The first
two most closely align with the UN definition of a long-term migrant. However, we
expanded on this definition of long-term activity in order to reflect the complexity of
people’s lives. This created two further categories which only make up a small proportion of
total arrivals.
57. However, as these additional categories do not align with the UN definition of a long-term
migrant, we have since removed these from our estimates. This is supported by analysis
from Census 2021, which suggested that including these arrivals expanded too far on the UN
definition of long-term migration.
58. After these additional categories had been removed the updated admin-based estimates for
EU nationals were around 98,000 higher than the Census 2021 implied immigration, based
on passports held as an indicator for nationality. The census likely underestimates migration
to the UK because it is an estimate for England and Wales rather than the UK as whole. It
only reflects intentions, which, as evidenced previously, do not always reflect actual
migration behaviours, and is based on passports held; EU passport holders who also held a
UK passport were not included in the census EU estimate.
3. Non-EU Nationals
59. We use visa data linked to travel events to estimate international migration of non-EU
nationals.
60. Census 2021 implied immigration, based on passports held as an indicator of nationality,
shows 264,000 non-EU nationals having arrived in England and Wales in the YE March
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2021. This is about 29,000, or 11%, lower than the estimate for the same time-point in the
updated UK back series.
IV. Conclusion and Future developments
61. Census 2021 provided a unique insight into the characteristics of international migrants
living in the UK in 2021.
62. Census 2021 also provided an insight into international migration across the last decade.
Along with other comparator sources, it provided confidence in our admin-based migration
estimates for EU and non-EU nationals and evidence to support the need to revise our
methods for measuring British nationals.
63. Our next steps for further improving UK level international migration estimates are focused
on producing admin-based migration estimates for British Nationals, which still relies on the
International Passenger Survey.
V. References
64. UNECE (2022) ‘Using administrative data to produce timely estimates of migration for the
UK (United Kingdom)’ available from:
https://unece.org/statistics/documents/2022/10/working-documents/using-administrative-
data-produce-timely-estimates
65. ONS (2022) ‘International migration, England and Wales: Census 2021’ available from:
https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/internatio
nalmigration/bulletins/internationalmigrationenglandandwales/census2021
66. ONS (2023a) ‘The changing picture of long-term international migration, England and
Wales: Census 2021’ available from:
https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/internatio
nalmigration/articles/thechangingpictureoflongterminternationalmigrationenglandandwales/c
ensus2021
67. ONS (2023b) ‘Analysis of social characteristics of international migrants living in England
and Wales: Census 2021’ available from:
https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/internatio
nalmigration/articles/analysisofsocialcharacteristicsofinternationalmigrantslivinginenglandan
dwales/census2021
68. ONS (2023c) ‘The changing picture of short-term international migration, England and
Wales: Census 2021’ available from:
https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/internatio
nalmigration/articles/thechangingpictureofshortterminternationalmigrationenglandandwales/
census2021
69. ONS (2023d) ‘The international student population in England and Wales: Census 2021’
available from:
https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/internatio
nalmigration/articles/theinternationalstudentpopulationinenglandandwalescensus2021/2023-
04-17
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70. ONS (2023e) ‘Dual citizens living in England and Wales: Census 2021’ available from:
https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/internatio
nalmigration/articles/dualcitizenslivinginenglandandwales/census2021
71. ONS (2023f) ‘Estimating UK international migration: 2012 to 2021’ available from:
https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/internatio
nalmigration/articles/estimatingukinternationalmigration2012to2021/2023-11-23
- I. Introduction
- II. What Census 2021 told us about international migration and the characteristics of migrants.
- A. Introduction
- B. Long-term international migration
- C. Short-term international migration
- D. International students
- E. Dual citizens
- III. Using Census 2021 to assure estimates of international migration over the last decade
- F. Introduction
- G. Admin-based migration estimates
- H. Revised admin-based migration estimates from 2012 to 2021
- 1. British Nationals
- 2. EU Nationals
- 3. Non-EU Nationals
- IV. Conclusion and Future developments
- V. References
