On 4 November 2006, the format for dialing mobile phones in Mexico was changed. For mobile phones, the digit "1" must follow the country code and precede the area code.
Example: +52-1-Area Code-Phone Number. See source below for area codes.
What if you try calling and the cell phone company is not letting the call through...all I hear is a message saying the number you are trying to call is not in service in that country