If calls don't ring and go straight to voicemail on your iPhone
Check your Phone app and Focus settings to make sure you receive incoming calls.
Before you begin
Check your Focus settings
Swipe down from the top-right corner of your screen to open Control Center.
Check your focus areas (for example, Do Not Disturb, Sleep, Work, and so on). If you see a focus area highlighted, tap and then tap again to turn it off.
Check your Phone app settings
Go to Settings, then tap Apps.
Scroll down and tap Phone.
Adjust your call settings as needed.
Under Calls, tap to turn on Wi-Fi Calling. This means your phone uses Wi-Fi Calling when a cellular connection is weak or unavailable. If you don't see Wi-Fi Calling in your settings, your carrier might not offer the feature.
Under Screen Unknown Callers, tap to select Never. This means calls from unknown contacts ring on your iPhone and are not silenced.
Under Call Filtering, tap to turn off Unknown Callers. This means calls from unknown contacts appear with other calls in your Recent calls list, and are not filtered to an Unknown Callers list.
Scroll down and tap Blocked Contacts to review unintentionally blocked callers. If you want to unblock a phone number, swipe left and tap Unblock.