The official figure of 900,000 UK citizens in the EU27 doesn’t include many non-registered, cross-border workers, and second-home onwners. We estimate, based on what we know of these populations, that there are two to three times the official figure if we include temporary or non-documented migrants.
Throughout the project we've been talking and writing about the problems of enumerating Britons overseas citizens. To find out more, here are a few resources from us: