iPhone 4 Caller ID Not Working After Unlocking with Gevey SIM

Hello Junthy, Caller ID Format Fix will not fix this error. You can easily fix and enable the Caller ID feature of your iPhone using itself through tweaking the location setting of your device. To fix this error all you have to do is launch Settings app from the SpringBoard of your jailbroken Phone, and then navigate to General -> International -> Region Format -> Select your country. After setting your location, reboot your iPhone and ask someone to call you to test if you have managed to fix the Caller ID of your device.

On the other hand, did you activate your iPhone? If not, then please do so in order to activate FaceTime and other features of the iOS to work on the jailbroken and unlocked iPhone. To activate, just simply insert the official SIM card or any AT&T SIM into your iPhone and then connect it to iTunes (do not forget to remove the Gevey SIM before activating). Just follow the onscreen instruction and you’ll be fine. No AT&T SIM card available? You don’t have to worry because you will still be able to activate your iPhone using SAM app. The step-by-step guide on how to download and use SAM to activate iPhone can be found here.