Long-term international migrants, UK: 2018

Other international migration outputs released today (28 November 2019) can be found on the following pages:

• Migration Statistics Quarterly Report: November 2019

• Population of the UK by country of birth and nationality, July 2018 to June 2019

• Home Office, Immigration Statistics, year ending September 2019

• Department for Work and Pensions, National Insurance number allocations to adult overseas nationals: January 2002 to September 2019

We are transforming our migration statistics, making use of all available data to get a richer and deeper understanding of migration. Since July 2018, we have been integrating outcomes from this work into the Migration Statistics Quarterly Report (MSQR). The latest update on this work, including a timeline of milestones on our transformation journey, was recently published.

On 9 October 2019, we published a call for feedback on our proposed approach to updating the annual migration tables. This followed the preliminary adjustments made in the August 2019 MSQR, where we were only able to adjust the highest-level tables because of further work being needed to develop a methodology for the more detailed data.

Many thanks for your feedback. We received a range of views, which we reviewed alongside the feasibility of applying an adjustment to the annual tables. Overall, users gave us a clear steer towards continuing to publish the annual tables in November so that the latest data would be available, even if we could not yet apply an adjustment to them. We have therefore published the annual tables with unadjusted data today (28 November 2019) but please note these estimates will continue to be provisional until final adjustments are developed by Summer 2020 and will be inconsistent with MSQR headline estimates.

Whilst we go through this period of development and innovation, we have sought to re-classify our migration statistics as "Experimental Statistics" in line with Office for Statistics Regulation guidance.

Estimates with preliminary adjustments applied are still available in our regular quarterly migration tables (Tables 1 and 2) alongside the unadjusted International Passenger Survey data (Tables 3 and 4).

Figure 1: More people have been moving to the UK than leaving every year since 1994

Long-Term International Migration to and from the UK, 1964 to 2018

Source: Office for National Statistics - Long-Term International Migration and International Passenger Survey (Table 2.00)

Our provisional annual Long-Term International Migration (LTIM), International Passenger Survey (IPS) and methodology tables for 2018 are published today (28 November 2019). Most of the tables contain information on migration by a number of other variables besides citizenship and reason for migration, for example, by age, sex, country of birth, occupation and country of last or next residence. Data on migration to and from individual countries are found in our four-series tables.

Net migration to the UK has been positive since 1994, with more people moving to the UK than leaving the UK every year since. For British citizens, net migration has been negative since 1986, meaning more British citizens emigrate than migrate to the UK (Figure 1) (Table 2.00).

In 2018, the largest inflows of immigrants to the UK were from (Table 3.20abc):

• India (58,000)
• China (52,000)
• Italy (27,000)
• USA (26,000)
• Romania (26,000)

For the first time, Poland was the most common destination to move to from the UK. Table 3.20abc shows that the largest outflows of emigrants from the UK in 2018 were to:

• Poland (24,000)
• Australia (23,000)
• France (22,000)
• Spain (21,000)
• USA (20,000)

The Office for National Statistics's (ONS's) long-term international migration statistics are estimated based on two main sources:

• the International Passenger Survey (IPS), which captures migration intentions
• Long-Term International Migration (LTIM) estimates, which are based on IPS data but with adjustments made for migrants not included in the survey, such as asylum seekers

International migration - table of contents
Dataset | Released 28 November 2019
The table of contents provides links to all annual tables on long-term international migration, including:

• Methodology tables (one-series)
• LTIM tables (two-series)
• IPS tables (three-series)
• IPS tables for individual countries (four-series)

Long-term international migrant

The Office for National Statistics's (ONS's) migration statistics use the UN recommended definition of a long-term international migrant: "A person who moves to a country other than that of his or her usual residence for a period of at least a year (12 months), so that the country of destination effectively becomes his or her new country of usual residence."

EU citizenship groups

EU estimates exclude British citizens. Citizens of countries that were EU members prior to 2004, for example, France, Germany and Spain, are termed the EU15; Central and Eastern European countries that joined the EU in 2004, for example, Poland, are the EU8; and EU2 comprises Bulgaria and Romania, which became EU members in 2007.

Full details of ONS terms and definitions can be found in International migration - terms, definitions and frequently asked questions.

The main data source for estimates of long-term international migration is the International Passenger Survey (IPS), which captures migrant intentions. The Office for National Statistics (ONS) publishes two types of estimates for long-term international migration: the IPS and Long-Term International Migration (LTIM) estimates.

LTIM estimates are based on IPS data but with the following adjustments:

• migrants not included in the IPS survey, such as asylum seekers and refugees, and migrants entering or leaving the UK across the un-surveyed land border with the Republic of Ireland
• migrants changing their intentions with regard to length of stay

LTIM estimates are only available by single characteristic. Where estimates involve more than one characteristic, such as estimates by citizenship and reason for migration, IPS estimates are published that are based solely on the IPS data.

The International migration statistics first time user guide describes these data and the Long-Term International Migration estimates methodology details the method used to calculate LTIM estimates.

For more detailed information on our migration statistics methodology, please see International migration methodology.

The International Passenger Survey (IPS) and the Long-Term International Migration (LTIM) estimates are currently the only sources of data to provide both long-term immigration and emigration and so net migration estimates for the UK.

The IPS is a sample survey and as such provides estimates. When the estimates are broken down beyond the headline figures, they are subject to greater levels of uncertainty.

The accuracy of long-term migration estimates

Surveys gather information from a sample of people from a population. It is not possible to ask every person travelling in and out of the country to fill out a survey. This means we have to estimate total changes, which can be affected by the group of people we sample. We use confidence intervals to measure uncertainty around the estimate. Users are advised to be cautious when making inferences from estimates with relatively large confidence intervals.

Preliminary adjustments to LTIM estimates based on all available sources

To get the best overview of trends in migration, we need to look at all available data sources. To help us address the impact of uncertain intentions for non-EU students at the end of their studies and for EU8 citizens moving to the UK, we have applied preliminary adjustments to our IPS-based estimates based on administrative data from the Home Office and from the Department for Work and Pensions (DWP). These tell us about people's actual behaviour and help provide a fuller assessment of migration patterns.

For EU migration, our preliminary adjustment applies up to March 2016, drawing on the strengths of what DWP data tell us about National Insurance number (NINo) registrations by people born in EU8 countries. From 2016, we have seen some changes to the trends in net migration for EU countries, and so we are reviewing what further data sources can add evidence on which to base an adjustment after this point.

For non-EU migration, our preliminary adjustment applies from 2012 through to the latest quarter. This draws on the strengths of what Home Office data tell us about emigration of non-EU students.

Currently, these adjustments are only available at the highest level because of further work being needed to develop a methodology for the more detailed data. As such, the preliminary adjustments have not been applied to the estimates in the annual tables, but we have continued to provide detailed breakdowns owing to user demand.

Fuller details on the methods we have used to apply adjustments to the data can be found in the research report.

Quality and methodology

The Long-Term International Migration Quality and Methodology Information (QMI) report contains important information on:

• the strengths and limitations of the data and how it compares with related data
• the uses and users of the data
• how the output was created
• the quality of the output including the accuracy of the data

For more detailed information on our migration statistics methodology, please see International migration methodology.