One SIM Card for 27 Countries
One of the greatest benefits of traveling within the European Union is the 'Roam Like at Home' regulation. Under EU law, mobile operators cannot charge extra roaming fees when you travel to other EU member states.
How It Works in Practice
If you purchase a prepaid SIM card from Vodafone in Lisbon or Movistar in Madrid, you can cross borders into Spain, Germany, Czechia, Austria, Hungary, Poland, Slovakia, and Slovenia without changing your settings, buying new cards, or paying extra fees. Your phone connects automatically to partner networks with zero roaming surcharges.
Important Caveats for Budget Travelers
- Fair Use Policies: European operators provide massive domestic data packages (e.g. 50GB in Spain for €15), but EU roaming regulations allow operators to set a 'Fair Use' roaming cap when traveling outside the purchase country (typically 10GB to 18GB of your total allowance).
- Non-EU Countries: The regulation applies to the 27 EU member states, plus Iceland, Liechtenstein, and Norway. It does not automatically apply to Switzerland, the United Kingdom, Serbia, or Bosnia and Herzegovina. If your train crosses through Switzerland or the Western Balkans, turn off data roaming to prevent steep per-megabyte charges.