http://unlockstar.com.ua/ – Official Factory Unlock for Apple iPhone 6,6Plus,5,5S,5C,4S,4,3GS.
Please take backup of your iTunes before you start (for safety reasons of losing data)
NOTE: USING THE SAME PROVIDER SIM CARD (THE PHONE IS LOCKED TO) TO DO RESTORE WORKS BEST FOR THIS PROCESS! You can use a DIFFERENT carrier GSM sim card as well
Make sure you are using the most UPDATED version of iTunes 12.1.2 or whatever is current version.
Make sure you update your iphone software to 8.1 or newest software available during restore for your phone model.
Here is link in case:http://www.apple.com/itunes/download/
Congratulations! Here are your unlock instructions:
Insert different SIM (not AT&T!)
1. Open iTunes on your Mac or PC and verify that you have Internet connectivity.
2. Ensure the original SIM card that came with this device is inserted in your iPhone.
3. Connect your iPhone using the dock connector to USB cable that came with your iPhone.
4. Backup and restore your iPhone using iTunes.
5. After restoring, your iPhone will be unlocked.
Insert a non-AT&T sim card in your iPhone, and use the USB cable to connect it to a computer with the latest version of iTunes. It might give you an error message. Disconnect the phone from the cable and re-connect it after 10 seconds. You will get the unlock message.
Insert a non-AT&T sim card in your iPhone, restart your iPhone, then go through the activation steps.
Insert a non-AT&T sim card in your iPhone, go to iPhone settings General Reset Reset Network Settings .
After restoring your iPhone will be 100% unlocked! iTunes show you congratulatory message: