Which side of the line each country falls on
Inside the zone, and therefore free on an EU plan: Croatia, Slovenia, Greece, Bulgaria and Romania. Outside it, and therefore charged: Albania, Serbia, Bosnia and Herzegovina, North Macedonia and Montenegro.
This is the single most useful thing on this page. Most Balkan itineraries touch both sides, which is why so many travellers here end up paying for something they assumed was included.
The routes where this actually bites
The Adriatic drive from Croatia down through Montenegro into Albania crosses the line twice. So does any trip that pairs Greece with North Macedonia, or Bulgaria with Serbia.
Albania in particular generates strong demand, especially from Polish travellers, because it has become a mainstream beach destination while remaining outside the roaming agreement.
Coverage is better than the reputation suggests
Networks across the region are modern and the cities are well served. Coastal Albania, Belgrade, Sarajevo, Skopje and Podgorica will not leave you stranded.
The mountains are where coverage thins, and the mountains are a large part of why people come. Plan the hiking days offline.
How to decide
If your trip stays inside the EU part, you probably need nothing at all on an EU plan. If it crosses into Albania, Serbia, Bosnia, North Macedonia or Montenegro, that leg needs covering.
For a route that crosses the line more than once, a regional plan avoids buying at every border. For a single country outside the zone, a country plan is cheaper.
Where are you going?
DestinationsCommon questions
Which Balkan countries are covered by EU roaming?
Croatia, Slovenia, Greece, Bulgaria and Romania. Albania, Serbia, Bosnia and Herzegovina, North Macedonia and Montenegro are not.
Why does Albania come up so often?
It has become a mainstream summer destination while staying outside the roaming agreement, so a large number of visitors arrive expecting inclusive data and do not have it.
Is coverage reliable in the mountains?
Less so, and the mountains are a major draw here. Treat hiking days as offline and download what you need in advance.
Do I need anything if I am only visiting Croatia?
On an EU or EEA plan, no. Croatia is inside the roaming zone and your home allowance applies.