Owners of the Samsung Galaxy S4 and the S3 who are still holding onto their locked handsets may be pleased to hear that they can unlock them thanks to a leaked code that is going around. If you own the handset you can unlock it easily by checking the steps below.
The leaked code is said to work with the Samsung Galaxy S4 along with the S3 and other devices and you can do it by inserting a new SIM card into the handset and then turning the device back on.
You can then open the dial pad and insert the leaked code *#197328640#. You can then check the steps below and follow them to unlock your Samsung Galaxy S4 or any other Samsung handset.
 UMTS >  Debug Screen >  Phone Control >  Network Lock > Options  Perso SHA256 OFF.
Now just wait for 30 seconds and you can then go back to the main menu and choose Network Lock. Choose  NW Lock NV Data INITIALLIZ and you will now have a handset that is unlocked.
The unlock code is said to work with the Samsung Galaxy Note 3 along with the Note 2 and other devices from the Samsung range.