I received my iPhone 5 today. We want to do an upgrade swap and activate it on another line. I'm following the instructions here (http://www.att.com/esupport/iphoneupgradesupport.jsp?source=ECSAFBFAC00D1000S), called AT&T, everything's going fine - but they need the SIM number and IMEI number. The SIM number is no problem, but I can't get the IMEI number without turning the phone on and activating it to the line we don't want, which will zap the SIM, so we'll have to go to the store to get a new one. The AT&T rep said the IMEI number should be on the box, but there is nothing there that looks like an IMEI number. My phone shipped from Apple, not AT&T, so it may have different information on the box. Is there any way around this besides activating on the wrong line and then going to the store to get the SIMs switched?