How To Call Mexico
From the US to Mexican phones:
To call land lines, dial 011-52 and then the number (example, 011-52-612-555-5555).
To call cell phones, dial 011-52-1 and then the number (example, 011-52-1-612-555-5555).
If calling a US number that is located in Mexico, dial 1 and then the full number, including area code (example, 1-213-555-5555).
These dialing instructions apply if you are calling from the US to Mexico, using a telephone with a US number, whether it is a land line, cell phone or Internet phone.