This is confirmed by myself to work on the AT&T Galaxy S3 and AT&T Galaxy Note 2 ....and it is reported to work on ALL VARIANTS of GSM.
I am posting it publicly to give where credit is due, and to KILL the eBay profits, specifically eBay Item: 321033698090
Please do not profit off someone elses' idea and eBay this info like the Joker in the auction above
To unlock your Galaxy S3 OR NOTE 2:
Just dial the following keys *#197328640#
Main Menu >  UMTS >  Debug Screen >  Phone Control >  Network Lock > Options Perso SHA256 OFF > (after choosing this option, wait about 30 seconds, then go back one step by pressing the Menu button then select Back, now you are in  Network Lock then choose  NW Lock NV Data INITIALLIZ ..... wait for a minute then reboot your phone... enjoy!!!
*This is a PERMANENT UNLOCK, and does NOT trigger anything for warranty
/standard disclaimer: I am not responsible if you don't follow directions and what you do with your phone
spnj said: .I see SHA256_ENABLE_FLAG  and choose  NW Lock NV Data INITIALLIZ waited a minute and restarted my phone... how to confirm if its unlocked ??Not sure if there's an easier way to find out, but I usually know someone who uses a different phone service and just use their SIM card to do a quick test. Your phone should recognize the SIM card and pick up the cell tower. Otherwise, I think it gives some message indicating it's for a different carrier or shows no signal.
Moderator Comment: Direct link to competing deal site removed. — Dec. 1, 2012 @ 1:15pm
Skipping 222 Messages...
posted: May. 12, 2013 @ 11:36a
Hi, Thank you all for sharing the information. For two days in a row I'm trying to unlock my sim on a new AT i747 I got from the US with no luck. I called ATT support and they gave me the unlock code but it didn't work. I was able to unlock the phone using the info you all shared. The bottom line - you must be on a stock 4.1.1 ROM in order to use the *#197328640# method. Any other ROM will not let you unlock the sim. I started with a 4.1.1 deadly venom ROM, tried 4.2.2 SlimBean than CM 10.1 and than stock 4.0.4. Only after reading other posts regarding the need for 4.1.1 I finally updated to 4.1.1 that had all the menu option including the  NW UNLOCK NV DATA INTIALIZES.
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