Newbie here. I upgraded on another line on our account thru AT&T with my sister-in-law who lives a few hours away. The new phone shipped tomorrow is under her number. Is there anyway I can activate it without activating the iPhone 6s and then taking her that SIM card and putting my existing SIM card in the phone? I would love it if I could just take my sim out if my iPhone 6 and place it in the new device but for some reason it seems like last year you had to initially activate with the sim car shipped in it? Just trying to avoid a trip for her to Att store or a trip of myself taking her the new SIM card.