Can't find the answer for this one. Whenever I've upgraded phones in the past, AT&T has allowed me to use any upgrade eligible line to "buy" the discounted phone, but assign it to my line, which usually isn't eligible. I have one of the kids lines upgrade eligible, but he doesn't want (or is that I'm not going to pay for) data service, and would like to use that "open" line to upgrade my wife's which is not yet eligible. I asked my local store rep, and that was as enlightening as a cavet with no flashlight.