There are some important facts to consider before you use your C Mobile SIM when abroad.

Sending a text or calling a non UK number may be more expensive than the standard charge. All rates include VAT
Because we're partnered with major UK network: Orange, you will be able to use your phone, just about, anywhere you travel in the world. Your phone should automatically be set to search automatically for the 'preferred' network when you arrive in your destination. You can check this by looking at your settings and network settings and checking 'auto selection'. Please note that this may vary by handset type.
To check your balance when you are abroad, we strongly recommend you use the USSD balance check feature, as this is free wherever you are in the world. Type #126# and press the call button to view your balance on your phone. Checking your balance or trying to top up using SMS will incur a charge.