Why my iphone is going straight to voicemail after one ring?

[iMore Question]

Whenever people try to call me my iphone 4 will only ring once and then it will go straight to voicemail. It will do that once or twice and on the third time it will fully ring. Sometimes it will not ring at all. It happens when people call me from different phones. Everything seems to be set correctly but I just don't know what could actually be happening. Thank you for your help.

 

[Larry Cook1]

On your keypad hit ##873283# and hit talk. Your phone will say starting service update. Hit Ok. Then it will say service update complete. Again hit Ok. That should fix it.

Posted via the iMore App for Android

 

[Marcus Adolfsson]

This can also happen if you use FaceTime on your Mac AND the application on your Mac has crashed. When the phone rings FaceTime on your Mac "declines" the call and sends it to voicemail. Force quit FaceTime or restart your Mac to resolve.