As of today, mobile networks across the EU will no longer be charging for data roaming across member states. The new ‘Roam like Home' legislation means that mobile customers across the EU (including the UK) can travel and use their allowance of minutes, texts and data without extra charges. However, there are still a couple of areas where surprise bills could pop up.
Today, Which? put out its own run down of the legislation, warning that some unexpected costs may still remain. Going forward, each time a European citizen crosses an EU border, whether it be for a day or an extended period of time, they can continue to use their contracted allowance of calls, texts and data without fear. However, included countries can vary depending on the network. For instance, O2 customers with a pay monthly contract won't be charged in the Channel Islands, the Isle of Man, Monaco and Switzerland. However, O2's pay as you go customers will be charged in those countries. Vodafone is the only network to include Turkey as a free roaming country. With that in mind, it may be best to double check your coverage before you head off on a trip.
It is also important to note that these new rules only apply if you are actually roaming. If you are in the UK citizen on a UK network and trying to call an EU country, you will have to pay extra for that. However, with the rise in mobile VOIP services, like Facebook Messenger, that may not end up being much of an issue.
KitGuru Says: While roaming is now much easier within the EU, there are a few loop holes in play at various networks. So, it's best to double check your coverage with your network to avoid any surprises.
You mentioned Switzerland and Monaco are included by some providers even though they’re not part of the EU (last time I was in Switzerland my network tried charging me 10 euro per mb)