Contact the customer-service center of your cell phone-service provider. If you're calling from Mexico you'll need to dial 001or the "+" symbol on your cell phone before entering the customer-service number.
Advise the customer representative that you would like to activate your phone for international calling. Inquire about the rates of service for international calls. Rates are higher for international calls and costs vary by provider.
Dial Mexico's exit code "00" and the United States country code "1," followed by the ten-digit phone number of the person you are calling, including the area code.
Press the "Send" button on your cell phone to connect the call.
