What is EU roaming?

EU roaming covers what happens to your data, calls and texts when your phone crosses a border inside the European Union. The wording varies by brand: included at 1&1, fair use at 1pMobile, paid at 2degrees, fair use at 3 Denmark and fair use at 4ka. Read the wording before you book, because a fair-use allowance is not the same as unlimited use at full speed, and a paid arrangement can add charges once you land.