Android customers:
- Open Truecaller > Click on profile icon > Tap on "Upgrade Premium" > restart app and try again.
- Force close Truecaller and try again. Or reboot your device.
iPhone customers:
- If you have switched device then try to Restore Premium.
- If you have re-installed or Premium was suddenly deactivated, try to restore as well. Please, do let us know if this has occurred.
- Reboot phone or force close app.
If the problem persists, contact us, and we'll make sure to help you on a high priority.
For more information about this, please see Apple's FAQ