How to Unlock Samsung Galaxy S4

Unlocking your Samsung Galaxy S4 so you can use a different SIM card.We would share the method of unlocking your T-Mobile Galaxy S4 SGH-M919 and AT&T Galaxy S4 SGH-I337.
Make sure your device is backed up. Messing around with SIM carrier stuff can be risky.

1. Dial the Secret Number
Enter *#27663368378#,it will take you to the Service Mode menu. If the above code does not work for you, try this: *#0011#.
2.Now select [1] UMTS
3.When you get into the UMTS Main Menu,select [1] DEBUG SCREEN
4.At the DEBUG SCREEN, select [6] PHONE CONTROL.
5.In the Phone Control menu,, select [6] NETWORK LOCK.
6.In the Network Lock screen, you should see three [3] PERSO SHA256 OFF.
7.Go back to the UMTS MAIN MENU, by tapping on the Menu button and then the Back key.
8.At the UMTS MAIN MENU, select [6] COMMON.
9.From the Common screen,select [6] NV REBUILD
10.At the NV REBUILD screen,Select [4] Restore Back-up.
11.Galaxy S4 will now reboot automatically.

Your Galaxy S4 will be unlocked.You’ll be able to use any other SIM card on it.