Hi, we are currently on a family plan with AT&T with 5 lines. I want to get the new iPhone 4S, but I am not eligible for an upgrade until February 2012. My dad's phone, however, is eligible for an upgrade. I know that a while ago, my mom's phone broke and she wanted to upgrade it, but she was ineligible at the time, so she used the upgrade from another phone on the family plan to upgrade hers. She did not have the other phone with her, and she kept her number. Upon checking for eligibility for upgrade for each phone, my mom's phone still had the previous eligibility date of February 2012, and the other phone now listed an upgrade time of March 2013. I wanted to know if I can use my dad's upgrade to upgrade my phone to the iPhone 4S, and if the Apple geniuses will do this in the store when I buy the new iPhone a week from Friday. Also, will I be able to do this if I call and pre-order an iPhone this friday? (Side questions: do you know if you can preorder an iPhone and pick it up in the apple store?). I have read other articles about people upgrading the other phone, and then switching the SIM cards, but this won't work because of the different-size SIM card in the iPhone 4/4S. Please help! Thanks guys!
Using someone elses upgrade on your family plan is not a problem. this is probably a case where you are best to do the activation at an ATT corporate store as they need to move some numbers around on your account and I am not sure how robust Apple's system are for this case.
What you can also do is order the iPhone and have it shipped to your house then call ATT before activating on your account. As for swapping sims and being different, the 4 and the 4s both will use the micro sim. The issue comes up with other GSM phones or the iPhones prior to the 4 using a standard SIM.
I would also expect that you can order an iPhone for pickup at the apple store. They have done this in the past. I just do not know if they can deal with your situation? They may be able to by calling ATT CS at the time you active the iphone on your account?
For service or support questions including existing order status, call: Customer Support: 1-800-331-0500
Information on iPhone unlocking can be found here by copying this link into your browser: https://www.att.com/deviceunlock/client/en_US/
What you could do is pre-order the iPhone 4S from Apple and then just bring the device to an AT&T Corporate store to do the necessary SIM swaps while keeping your old numbers. From memory, when I used my brother's upgrade to get myself an iPhone 4 and gave him my old 3GS, the AT&T rep just issued a new SIM card for the 3GS. I did buy Apple Care so as not to get hit by the $25 fee.