The options for using a cell phone in Mexico are:
1. If you´re not expecting any calls, you can turn off your phone data and use a wifi connection when you can find one.
2. If you need to call someone during your time in Mexico, you should speak to your phone service provider about international calling. Some providers have lower prices than you would normally pay for calls outside of the United States, and that could save you a lot of money if you know you´re going to be using your phone a lot.
3. If you have an unlocked phone you could buy a Mexican cell phone chip for your phone so you could make calls without having to pay for your calls.
4. If your calling someone in Mexico, than the number is preceded by a 3-digit access code. So when calling someone in Mexico, dial 044 first then the 10-digit number of the phone number. If your using a phone outside the area code that you´re calling from, dial 045 first.
