Detail

A normal call is simply called Direct call, and call back is when you make the call, either initiated via the web, text message, or via a call that's terminated immediately. 

You receive calls rather than make them, but their can be roaming charges, just for receiving a call

Best of all, there is absolutely no roaming costs in EU countries and 90 countries + worldwide. To receive a call, its FREE in the 90 Countries, and calls are affordably priced in the remaining destinations as well.

Roaming Sim Card Information

More Information at

www.great-britain-uk.co.uk

Some mobile operators, need you to activate roaming before your go abroad, this is usually because roaming charges are high and then need to ensure your credit rating on your subscription allows you to use your mobile abroad. However, one answer is  to keep your current mobile phone and simply change the sim card in the back to an International Sim Card. This will then allow you to have a UK number, avoiding most roaming charges and benefiting from cheap international calls from your mobile.