For some time I have had an ATT 450 minute plan with my iPhone and I am eligible for an upgrade. I travel frequently overseas. I would like to get an unlocked iPhone 4s and continue my ATT Monthly plan utilizing an ATT sim card and retain my current phone number.
My question is: When I remove the ATT sim card from the phone what happens to my incoming calls and incoming text to my current phone number? Can I still call and retrieve my voicemail? Will textstill come to my iPhone when I replace the ATT sim card?
If you use your upgrade to get a discounted Iphone 4s, it will be locked regardless of whether you purchase from AT&T or Apple. The unlocked Iphone 4s will only be available from Apple and you will have to pay full retail price for it (but it won't use up your upgrade eligibility).
Regarding your ATT SIM, if you remove it from the phone, its pretty much the same as turning the phone off. All calls to that number will go straight to voice mail, unless you have set up call forwarding. I don't think there is any way to set up text forwarding, so texts won't be delivered until you put that SIM back into the phone. If you put in a different SIM, that SIM will have its own phone number and the iphone will only receive calls and texts directed to that number.
Regarding retrieving your voice mail and presuming that you retrieve by calling the appropriate voice mail access number and enter a password/pin, you should be able to do that whether you have your ATT SIM in the phone or an international SIM in the phone. Just keep in mind you will pay the appropriate rate for whatever voice mail number you call.
*The views and opinions expressed on this forum are purely my own. Any product claim, statistic, quote, or other representation about a product or service should be verified with the manufacturer, provider, or party.