How do you call each other with UK mobiles in Europe?

Answer 1

The most reliable way to place calls from a mobile phone when you are traveling internationally is to always use the full international number. All GSM mobiles and some other mobiles allow this method.

For any UK number (landline or mobile), replace the trunk prefix 0 with the UK's telephone country code +44. For example, 07700 900123 would become +44 7700 900123. (Note that Italy is an exception to the general rule about dropping the trunk prefix 0. Italian landline numbers begin with +39 0.)

Also note that you always dial the UK number for a UK mobile, even when it is roaming in some other country. The network will automatically locate the mobile, and the roaming user will pay any surcharge, based on his or her calling plan.

(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)