Calling a cell phone in another country
Do I need area codes?
In most countries cell phone numbers are not geographical. Instead they have their own unique codes/starting digits used nationwide. This is not the case for several countries: Argentina, Brazil, Canada, Mexico, USA and some Caribbean nations. In these countries you can not differentiate a cell number from a landline because they all use area codes.
- Dialing from the USA to a UK cell phone: 011
+ 44 + 7??? ??? ???
!!! The UK cell number will have the same format (7??? ??? ???) countrywide
- Dialing from the UK to a USA cell phone in Las Vegas: 00
+ 1 + 702 ??? ????
!!! As you can see the Las Vegas cell number looks just like any other Las Vegas number, landline or cellular
Should I add any digits to the cell number my friend from country X gave me?
Only if your friend is in a country where area codes are used for cell numbers, and only if the cell number doesn't already incorporate the area code.
Should I drop any digits?
If you were given a cell number starting with zero you must drop this digit.
For example, if your friend in the UK gives you a mobile number of the format 07??? ??? ??? and you are in the US, the digits you will dial are: 011 + 44 + 7??? ??? ???.
Where can I find more info?
This website provides complete cellular numbering format information for most countries.