1.2 million people born in the UK live in other EU countries, according to 2015 estimates from the United Nations (UN). Around 900,000 UK citizens were long-term residents in other EU countries in 2010 and 2011, according to census data across the EU collated by the Office for National Statistics (ONS).
There are two alternative estimates, and neither is perfect
Recent figures on Brits abroad have been compiled by both the UN and the ONS. Both are based mainly on census data gathered from EU countries in 2010 and 2011. The difference between them lies in what’s been done to those numbers.
The ONS looks at both UK-born people and UK citizens. It brings together mainly census figures from across the EU from 2010 and 2011. The figures just cover people who live abroad for at least a year, rather than just short-term emigrants.
The UN looks just at UK-born people. It takes the census figures as a starting point and then ‘ages’ the figures a few years up to 2015, estimating how many people have immigrated to and emigrated from those countries during that period.
The UN data isn’t a perfect measure, as different counties define “immigrant” differently. Some define their migrant population as those born abroad; others count foreign citizens. As the House of Commons Library comments, this is an “unavoidable limitation” of using these figures to compare countries.
So the UN estimate is more up-to-date; the ONS estimate is more certain.
In the context of the Brexit debate, the figures on citizenship are arguably more relevant. That’s because free movement rules are based on which country you’re a citizen of, rather than where you’re born.
Where UK citizens lived in 2010 and 2011
Spain hosts the largest group of UK citizens living in the rest of the EU at an estimated 309,000. France is second with 157,000 and Ireland next with 112,000.
Where UK-born people lived in 2015
Spain is again top of the list: an estimated 310,000 UK-born people lived there in 2015. Ireland is second with 250,000 and France third with 190,000.
Those 1.2 million people place the UK fifth among EU countries for the size of their expat population in other EU member countries.
Previous estimates have placed the figure higher, but these aren’t the best or most recently available figures
An older estimate by the IPPR think tank estimated that 1.8 million UK nationals lived in other EU countries for at least a year in 2008. This rose to 2.2 million when including people who lived abroad for at least part of the year.
This was produced before all the census data used by the UN was available, so the researchers filled in the gaps using various assumptions.
Update 29 March 2017
We have updated this to say the ONS collated information rather than the ONS collecting information.