The main reasons for not receiving calls on an iPhone include having "Do Not Disturb" mode accidentally turned on, network or carrier issues, or software glitches. The "Do Not Disturb" mode is indicated by a moon icon in the status bar, and when enabled, it silences calls and notifications. It can be turned off by swiping up (or down on newer models) to open Control Center and tapping the moon icon. Additionally, iPhone settings or recent iOS updates, signal problems, or needing a restart might also be factors that prevent calls from coming through.
Would you like detailed troubleshooting steps for each possible cause?
