So, I thought I’d post this information for anyone else in my situation.
I was on contract with Alltel (in Mammoth Lakes, CA). I was given the unlimited data plan through Alltel back in fall of 2010. Alltel did not offer many smartphones with this deal, so I was issued an HTC Hero (Android) with the plan. At the time, they told me that AT&T was buying out Alltel in our area, and so our plan would be converted to an AT&T plan when the buyout was complete, but that all plan details (including unlimited data/text) would be preserved. The buyout took place, and so my old phone stopped working, and the new phone I got from AT&T (an HTC Aria, Android 2.2) was activated (in February of 2011).
After calling AT&T directly to check on my plan status, I found out some interesting details. Apparently, I can’t manage my “Circle” (an Alltel feature that let me have free calls to 10 people I identified as in my circle) any more, now that the Alltel plan is an AT&T plan. All features of my old plan are permanently locked, and I can’t change my circle, or make any adjustments to my old Alltel plan. I cannot log into the “My AT&T” web portal, and see the details of my plan. They won’t be adding this in the future. They won’t convert my old login info to the Alltel portal (which I used to adjust my circle numbers, etc.). More importantly, the customer service rep at AT&T told me if I ever wanted to upgrade my Alltel plan to the latest and greatest smartphone (or an iPhone) I would have to cancel my Alltel plan and move to a limited-data plan under AT&T.
I didn’t change at that time, since I like having unlimited data, and the Aria was serviceable, if not really up-to-date any more. If I upgraded to any AT&T subsidized smartphone, they would demand I change plans.
So, I ended up purchasing an unlocked iPhone 4s from Apple directly. That went smoothly. Apple must have phenomenal order fulfillment, because I ordered on a Thursday afternoon at 4:45pm, and received the phone the very next day, at about noon.
Since my AT&T-issued HTC Aria had one of the larger SIM cards, I couldn’t just swap it out into the new iPhone 4s. I thought about cutting the card down to size, and even bought a SIM cutter. But, I thought I’d stroll on down to the local AT&T store here in Mammoth Lakes to see if they would just swap my info to a micro-SIM card (which will fit in the new iPhone).
Turns out they are happy to do it. I just told them I needed my info transferred to a new micro-SIM card instead of the one in my Aria. I told them a story about traveling abroad, so I’d need to buy an unlocked phone. Since AT&T doesn’t sell carrier-unlocked phones at all, they didn’t give me any flak. But, I honestly don’t think it matters, so you probably don’t need to make up a story. Just tell them you are buying an unlocked iPhone from Apple directly.
Anyway, they looked up my info on the computer, grabbed a micro-SIM, scanned it, and voila! The new micro-SIM was activated with my phone number, and ready to go. They charged me $29.00 for this service. Note that whatever phone you currently have is now useless, since the moment they activate the new SIM, the old SIM stops working.
With the new micro-SIM in my hot little hand, I popped out the micro-SIM slot on my new iPhone 4s, and put it in. It only fits one way, so no worries there.
I connected it to iTunes, and turned it on. After following the prompts, the AT&T carrier logo popped up on the main screen, it was activated. I could now send and receive phone calls and text messages on my new factory-unlocked iPhone 4s.
But, there was a problem! I had used the WiFi on the iPhone 4s to connect online, and so I turned it off, thinking I would use the 3g. No dice! I got an error that no data connection was available. A pop-up came up that said “Could not activate cellular data network. You are not subscribed to a cellular data service.” I began to panic. Did I just screw myself out of unlimited data? I knew I had a data plan, since it worked perfectly with my HTC Aria just minutes before. Did AT&T have an evil agenda to keep people from upgrading their own phones even though it was purchased unlocked from the factory?
Nope. Turns out that in order to use 3g data, you must set something called the APN Settings on the new iPhone. These APN settings allow the handset to use 3g data connection just as you have before. It took some Google-fu, and there was some confusion about how to set the APN settings. Some sites said you just had to edit your APN settings by going to “Settings” then “General” then “Network” and then “Cellular Data.” Well, I didn’t even have Cellular Data, and nowhere to edit APN settings at all!
Turns out you can either use the iPhone Configuration Utility (free download from Apple) or have a website do it all for you!
To use the easy option, on your new iPhone 4s, turn on WiFi and connect to the Internet. Open Safari, then browse to: http://www.unlockit.co.nz then click “Continue.” Select “Custom APN.” Select your country (United States, in my case) and then select the Carrier from the list (I chose “AT&T”). Click on Create Profile, then Install, and then you’re done. 3g will now work on your phone.
Anyway, I hope that helps anyone else upgrading to a factory-unlocked iPhone 4s from the old Alltel plan, which converted to AT&T. Cheers!

