Steve,
IMHO, this should be up to the client. Since international phone numbers vary widely in structure, there may be no universal formatting. Check how their data-entry people want to see the data....

HTH
Barbara

>I am working on an app that will use international phone numbers. What's the best way to handle international phone numbers in coding, input masking, formatting, etc., where you have to dail 011 + country code + city code + number.
>
>Should I make two fields? One for international prefix and one for regular phone number or what?
>
>Thanks for the advice.