Citizens of European Union countries have the right to move between EU countries. As of 2015, nearly 20 million people, or about 4% of the EU’s birth population, lived in a European country in which they were not born.

EU countries with the highest number of migrants from other EU countries include Germany (5.3 million), the United Kingdom (2.9 million) and France (2.3 million). Meanwhile, EU countries with the highest number of migrants to other EU countries include Poland (3.5 million), Romania (3 million) and Germany (1.8 million).