So I just got off the phone with AT&T and they granted my unlock on my 4s also received a confirmation email on how to do it. Now this lady said for me to unlock the phone I have to remove the ATT sim card and insert another carriers sim card in, and then restore in order to unlock. Is this really needed why would I need to insert another carriers sim to unlock it? It's weird to because in the instructions that were sent out to me via my email it says nothing about inserting a different sim it simply says to back up and restore, and after that it will be unlocked. So basically could I unlock with or without a sim card inserted? If I do it now would my 4s not work (my iPhone 5 wont be here till Friday)? I'm selling my phone on ebay and don't have another carriers sim so I'm a little confused...told the rep I'll contact them back if I run into any problems.