How to unlock a Nokia Lumia 521 mobile with AT&T network?

[Windows Central Question]

Hi,

how to unlock a nokia lumia 521 mobile. i tried with cellunlocker.net but they couldnot get any code to unlock it was not success.. Please let me know is there any other way to unlock the mobile

 

[Laura Knotek]

You'll need to get the unlock code from T-Mobile.