I didn't want to start a new thread to ask this...
I upgraded from a Lumia 920 to a Lumia 1520. I was able to keep my 920 and want to sell it. I requested an unlock code from AT&T and they sent it to me but the instructions say I have to insert a non AT&T SIM card to do the unlock process. Is this true or can I just unlock it with my AT&T SIM or no SIM?
Any non AT&T SIM should suffice. You need some form of non-native SIM in to pull up the unlock SIM screen easier.
If you dont use another sim card, just type ##7820# and the screen will prompt to you place the code...
