The new legislation, dubbed "Roam like Home", means that at United Kingdom mobile phone users can use their regular allowance of calls, texts and data for no extra cost from anywhere in the EU.
Up until now, roaming charges have been added onto to the cost of calls, texts and internet browsing when citizens of an European Union country traveled to another member state and connected to a phone network there. In other words when you come to Norway this summer, you'll pay the same rates as you do at home.
However, less than 40% know the specific details of how the new rules will affect them.
Currently, 38% of Irish holidaymakers avoid using data while overseas out of fear of coming home to a large bill or burning through their data allowance.
To this end, Three has stated it won't increase prices after Brexit and Vodafone UK believes that market forces will help roaming charges competitive.
But do I have to pay to receive a call?
No, those charges have gone.
And what about French providers?
Many of the Swedish providers, and indeed providers in other parts of the European Union, anticipated the change in the law which has been in the pipeline for a long time by scrapping them before the official date. This will leave users still incurring roaming charges if they exceed that cap. A fourth company, SFR, is expected to follow suit on June 15th. This is meant to prevent people taking out a contract in a lower-cost country to use elsewhere. This means you are at a higher risk of going over you allowance.
If you have unlimited data then you need to check with your carrier about their fair use limit, if you go over this they will charge you €7.70 per gigabyte, this will be reduced to €2.50 in 2020.
There is a chance that your phone can pick up a signal from another country without you noticing (when sailing around Kos, off the Anatolian coast of Turkey, for example).
"Not knowing what's included in your tariff could lead to some surprising charges on your next bill". They, however, still have been given power to introduce minor charges on roaming calls and data usage.
Facebook, Whatsapp and Skype all let you make voice calls over the internet - that could be using 3G or free WiFi at your hotel or even in a cafe. I have been a Three customer for a number of years as it already offered excellent European Union and worldwide roaming options but the company has now added some further "Feel at Home" destinations to strengthen its appeal - such as Brazil.
And in October 2015, the European Parliament and the Council agreed that this should be in place on June 15 2017.