Why does calls go directly to voicemail on my iPhone 15 Pro?

Make an appointment at an Apple Store or authorized Apple service center and have your iPhone evaluated. What you are experiencing is by no means common nor expected and, absent any details about your exact situation, indicates a possible hardware issue with the cell processor or antennas.

Regards.

1. Check to see that the Silent switch is not set to ON. Silent switch is located on the Top Left Sideof your iPhone.
2. Open Settings ➔ Sounds & Haptics ➔ Ringer and Alerts : Make sure this is not set to OFF or too Low. Set Change with Buttons to OFF. Below that Make sure that there is a Ringtone selected.
3. Check to see that Silence Unknown Callers is set to OFF. Open Settings ➔ Phone ➔ Silence Unknown Callers : Set this to OFF
4. Make sure that a ringer sound is assigned. Open Settings ➔ Sounds & Haptics ➔ Ringtone : Ensure that a Ringtone is assigned here.
5. Check to see that Do Not Disturb is set to OFF. SWIPE DOWN from the TOP RIGHT CORNER of your screen. This will reveal the CONTROL CENTER. Find the FOCUS button (should be highlighted in white if Do Not Disturb is ON) and Tap on it. This should turn OFF Do Not Disturb.
6. If all of the above is OK on your iPhone then Try and Force Restart your iPhone EXACTLY as shown below and see whether that resolves the issue:

• Press and quickly release Volume UP button
• Press and quickly release Volume DOWN button
• Press and Hold the SIDE button until an Apple logo appears and then release the Side button (Can take up to 20 seconds. (DO NOT release Side Button when invited to Slide Power OFF). 

Axel F.

I’m really disappointed in the poor reception of these overpriced phones. I’ve avoided Apple phones until now, but software updates have cost so much in lost business that I gave up and bought and bought a 15Max Pro. It has the worst reception of any phone I’ve ever owned and is costing me even more lost business.

Apple will never admit to cutting corners, but as soon as I can find a reliable Android my iPhone will be up for sale.

Answer or decline incoming calls on iPhone

Answer or decline incoming calls on iPhone - Apple Support (CA)