I cannot believe how hard it was to find this information online. I searched for all kinds of phrases and keywords on Google and AT&T’s forums, but couldn’t find the answer to my specific question. If you’re in the same boat, hopefully this post will save you much frustration.
Joanna and I both had our own iPhone 4S’s in separate AT&T accounts. I wanted to add her iPhone as a second line on my account, and then put them both in a FamilyTalk plan. After a quick trip to the local AT&T store this morning, we learned that Joanna first had to initiate a Transfer of Ownership. The AT&T representative told us that could only be done over the phone, but I knew better.
Once back home, we logged on to Joanna’s AT&T account, and all she had to do was go to the “Wireless” tab and then click on “Transfer Account Ownership” under “Account Changes”. After entering my name and email address, I got an email asking me to confirm the transfer. From that point, I just followed the self-explanatory instructions on the website, and now we’re all set.
By doing all of this online, we saved $18, which is what AT&T charges for performing the transfer of ownership over the phone.