Can I purchase a cell phone in USA and activate with plan in Mexico City?

Answer 1

That depends on a lot of factors. First, the phone must not be locked to a US provider. Next, the Mexican provider must accept phones from other providers. GSM phones this step does not apply to as you can just stick the SIM card into a network compatible phone. Finally, the digital technology of the US phone must match that of the Mexican provider you wish to use the phone on. CDMA phones need to go to CDMA networks, GSM to GSM. Don't bother with TDMA or iDEN. If all the conditions are met, you should be alright. I've activated Mexican CDMA phones on a US CDMA network 7 or 8 years ago.

Answer 2

You can with any company here in mexico but the problem is taht most "american" phones are locked.(and I say "american" because I bought one there, then have it unlocked and activated in mexico and later found out in the package that it was made in mexico, ironic isn't it???) You gotta get an unlocking code from your provider and then u have to find someone who would unlock it for u either there or here in mexico.

Ussualy the people who do that here, have a list of phones that can be unlocked, you gotta be carefull with what phone u buy or they migth not be able to unlock it.