Mobile Device Unlock: Apple iPhone 3GS

Learn how to use the Mobile Device Unlock code of the Apple iPhone 3GS.




SIM unlock phone


The Mobile Device Unlock code allows the device to use a SIM card from another wireless carrier. This may be necessary when traveling internationally. To enter the Mobile Device Unlock code, follow these steps:


Important: Stop if you receive an error message. The device may lock permanently if you enter the incorrect code multiple times.


  1. See if your phone is eligible to unlock: Mobile Wireless Device Unlocking.
  2. Contact Customer Care to request the Mobile Device Unlock code for your phone.
  3. Ensure you have received the Mobile Device Unlock email and followed the instructions.
  4. If available, insert the non-T-Mobile SIM card into your device.
  5. Connect your device to a computer running iTunes.
  6. Complete a backup of the device information.
  7. Disconnect the iPhone from the computer.
  8. Complete a master reset using the Erase All Content and Settings option.
  9. Once the master reset has completed, reconnect the iPhone to the computer.
    • Note: Do NOT complete the initial setup process prior to plugging the device in.
  10. When successfully unlocked, the message Congratulations, your iPhone has been unlocked will appear.
    • Note: It may take a few minutes for this message to appear.