iPhone Dev Team released Ultrasn0w 1.2 unlock for iOS 4.2.1.
To unlock your iPhone with iOS 4.2.1 or 4.1, you need to update your iPhone baseband to 06.15.00 from iPad iOS 3.2.2. If you want to be notified when the unlock for 4.2.1 directly without updating comes out subscribe our RSS feed , twitter or Facebook. You will get all the latest updates at both the places.
If your iPhone’s baseband is 05.14.02 or 05.15.04 you need to upgrade your baseband to 06.15.00. Click here to upgrade your iPhone baseband to 06.15.00 with PwnageTool or to upgrade iPhone baseband to 06.15.00 using redsn0w.
Once your device baseband is upgraded to 06.15.00, follow these steps to unlock iPhone using ultrasn0w 1.2.
These instructions will help you unlock iPhone 3G / 3GS with basebands:
How to unlock iPhone with ultrasn0w 1.2 using cydia
1. Launch cydia on your iPhone
2. Select manage tab from the bottom options
3. Select sources button
4. click Edit button on top right of the screen
5. press Add button on top left of the screen
6. enter http://repo666.ultrasn0w.com/ as source url and press add source button (Note: ultrasn0w includes a letter 0 (zero) not alphabet o).
7. Once the source has been added, return to cydia
8. press Done on the top right of screen
9. Select http://repo666.ultrasn0w.com/ from the list of user entered sources in cydia
10. Select ultrasn0w from the packages list
11. Press Install button on top right of the screen
12. Press Confirm button on top right of the screen
13. Reboot the device once the installation completes successfully.
14. Reboot the iPhone again (recommended)
15. Insert sim of any carrier of your choice and confirm that it’s working perfectly.
Your iPhone is now unlocked successfully!