When roaming internationally with a mobile phone, dial based on the country you are currently located in. Do not dial based on the country the mobile phone is registered.
A mobile user whose cellular phone is based in the United States is standing in France dialing a call to Germany.
This user would dial the call with the call sequence of France to Germany.
A mobile user whose cellular phone is based in New Zealand is standing in Canada dialing a domestic call within Canada.
This user would use the Canadian domestic call sequence.
A mobile user whose cellular phone is based in the United Kingdom is standing in Australia dialing a call to the United Kingdom
This user would use the international call sequence of calling from Australia to the United Kingdom.
Rates vary by carrier.
Often there is an additional roaming charge for calling through the roaming country.