Overview
The Device Not Registered error occurs when the phone number detected by your SIM card does not match the number on the YouMail account you’re trying to activate. This guide explains why this happens and how to resolve it so your calls can forward correctly to YouMail.
If you see a message stating that your device number is not registered, YouMail is receiving a different phone number from your device than the one on the account.
Key benefits / use cases
Identify number mismatches: Understand when your SIM number doesn’t match your YouMail account
Restore call forwarding: Ensure missed calls route correctly to YouMail
Prevent activation failures: Fix device and SIM setup issues before retrying activation
How to fix the device not registered error
This process ensures the phone number provided by your SIM card matches the number registered on your YouMail account.
To resolve the Device Not Registered error, follow these steps:
Confirm that the SIM card is inserted in the primary SIM slot (SIM 1) on your device.
Ensure YouMail has permission to read phone information:
Go to Settings
Tap Apps
Select YouMail
Tap Permissions
Enable Phone (or Phone state, depending on device)
Review the error message showing the phone number listed as not registered.
Sign in to the YouMail account that matches the phone number detected by your SIM, or
Add the detected phone number to your existing YouMail account and activate it.
Important: If the SIM-provided number does not match the number on your YouMail account, activation will fail until the numbers align.
Why this error happens
The Device Not Registered message means:
Your SIM card is providing a different phone number than the one currently on the YouMail account
The detected number is not registered to the signed-in YouMail account
Dual-SIM devices may be using the wrong SIM slot during activation
Note: YouMail relies on the SIM-provided number to confirm ownership during activation.
After fixing the issue
Once the correct number is signed in or added to your account:
Activation should complete successfully
Missed calls to the correct number will forward to YouMail
Voicemail handling will begin immediately after activation
Tip for dual-SIM devices
If you use a dual-SIM phone, temporarily disable the secondary SIM or move your primary number to SIM slot 1 before activating YouMail.