TMO is our area worsens, and the Mrs. has problems getting a signal at home. Verizon insists on both data and voice plan if we use a smart phone. I called AT&T and got same answer.

Question: we have an unlocked iPhone 3gs that works perfectly fine with TMO. So can I go into AT&T store, bring along an older non-smart phone, port my wife's TMO to AT&T, activate it with voice ONLY, use for a few days, then swap sim card into iPhone?

AT&T CS insists the answer is NO, their network will register a different IMEI number. Is that true?

Yes. It is true. Been there, done that. You have two solutions. Get a third party phone that Apple doesn't sell (and isn't Blackberry or Android) and pray or go with an MVNO (H20, Pocket Red, etc).

Not aware of any of the big four that offers a smart-phone without a dataplan.

All else fails, get a microcell for your carrier. If you complain enough, and have service long enough, they'll usually comp you the hardware. Go from getting 0.5/bars from the tower, to 5/bars inside the hosue.

Does her phone have T-Mobile's Wi-Fi Calling feature? This eliminated the indoor signal strength problem at our home, and has greatly improved the battery life.

Can you use a goPhone SIM and turn off data access on the iphone?

Possibly. A Walmart Straight Talk prepaid SIM works in an ATT iPhone, even if it is locked.

Thanks for all the comments.

1. TMO's wifi [UMA] does not work on apple iPhones - i offered her my old BB which has UMA but she declined
2. She wants a larger screen so traditional non-smart phone won't do - again,i have older samsung with UMA call feature that would work, but she declined!
3. Prepaids are not economical - plus I don't think you can't port existing number to prepaid

So we're debating whether to switch her over to Verizon, get a new iPhone 4s or to wait for new iPhone later this summer before making the switch. Regardless, her mobile phone bill is going to get a huge spike when we make the move!

Get a USB modem from Clear (it cost $49.99 for unlimited data) and setting up a personal mobile hotspot via a Cradlepoint device or this is how to use data on the iphone with a Straight Talk sim card http://www.ehow.com/how_12209600_mak...-sim-card.html

AT&T prepaid has unlimited voice and text for $50/month. This is cheaper than a plan with 2 year contract. Just purchase a prepaid AT&T SIM card and insert it into your unlocked iphone and call AT&T to port your number from T-Mobile. Simple as that!

I am certain the answer to the original question is "Yes", you can port in to AT&T on a pre-paid or post-paid plan. AT&T Wireless offers voice-only monthly contract plans. AT&T also offers decent pre-paid plans: $50/month with unlimited voice/text (I think the base contract plan is $39.95 for 450 min.), or $2/day unlimited voice/text only on the days you use the service.

You can activate an AT&T pre-paid SIM either in a non-iPhone (you must be in the U.S.), or on-line using an AT&T iPhone IMEI. You can then use the SIM in an unlocked iPhone. You can add a data plan on top of a pre-paid SIM. I have colleagues who have done this many times.

The biggest challenge is cutting a normal-sized SIM down to a uSIM.

In any/all cases you should not tell AT&T you have an iPhone.

edited to add: You could also port in to Straight Talk, the pre-paid MVNO using the unlocked GSM SIM (uses AT&T's network) ($14.99) and a $30 or $45/month plan.

[Quote] The biggest challenge is cutting a normal-sized SIM down to a uSIM.

** micro sim cards (iphone size) are now available = ebay etc **

Unfortunately we want to migrate to Verizon, not AT&T.

Are you asking if you can go with your 3GS on VZW? If so, not possible. 3GS was GSM only. Another option would be one of the MVNO outfits, like Cricket or similar. You do have to pay for the phone up front but can get away with a voice/text only plan.

Cricket is an actual carrier, not a mvno. They are also cdma so that wouldn't work.

FWIW, you don't need a data plan with the original 2G iPhone on AT&T. Their network won't be able to detect it and force a data plan upon it.