How do you dial a North American mobile number which is in Dublin and trying to reach another North American mobile number in a Dublin and b Belfast?

Answer 1

The physical location of the mobile phone you are calling does not affect its telephone number. To reach a North American mobile phone, you always dial its North American telephone number.

However, the fact that you yourself are using a North American mobile in Another Country does affect how you dial any call on that mobile phone. If you just dial a North American number in domestic format, your call will fail, or worse, go to a wrong number.

The most reliable method is to dial the number in full international format, beginning wtih the plus symbol. (Different phones have different methods of entering the plus symbol. "Press and hold 0" is a popular method, but there are others.) For a North American (USA, Canada, etc.) number, just prefix the ten-digit number with +1; for example, +1 617 555 0123

If you store numbers in your phonebook in international format, they will work correctly from any country, even including the USA and Canada. The mobile phone network will automatically interpret the number correctly, without your having to worry about national and international dialing prefixes.

Also, note that in your scenario, both North American mobile users will pay roaming rates, and the one who initiates the call will pay international call rates for a call from Dublin to North America, even if the other mobile is in the same room. The rates will vary depending on your provider and calling plan.