A European Union (EU) law to abolish roaming charges for people using mobile phones abroad comes into force today.
The new rules mean that citizens travelling within the EU will be able to call, text and browse the internet on mobile devices at the same price they pay at home.
The European Commission said the end of roaming charges was one of the greatest successes of the EU.
Until now roaming, or connection, charges have been added to the cost of calls, texts and internet browsing when consumers from one EU country travelled to another and connected to a mobile network there.
In some cases, mobile users have faced bills of hundreds of pounds if, for example, they have downloaded a film.