IPhone – Cannot make or receive calls on the Mac from the iPhone

These troubleshooting steps helped me resolve this on one account:

• delete all pairing records in BlueTooth (Or at least all iOS pairing records) and then power down the Mac.
• disable the setting to disable "iPhone Cellular Calls" in the FaceTime part of the settings app.
• power down the iPhone 5 and start it back up. Don't launch any apps on the phone other than the settings app to enable "iPhone Cellular Calls"
• Start up your Mac and log in if needed.

Try a call or two. The delay for me is between 1 and 4 rings of the phone in general for the first call of the day. Things seem to notify me on my iPad before my Mac so if you have one of those, you could test handoff with it as well in case it's just your Mac that's not receiving the call notification.

If the above steps don't resolve your issue, you might have to set the date/time correctly on the Mac (to within 2 minutes of the iPhone's time - both to sync automatically if possible) and then sign out of FaceTime on the Mac. At that point, reboot the Mac yet again and sign in to FaceTime.

If that fails, you might have a hardware issue or severe bluetooth interference in the location where you are testing. Neither of which are going to be speedy or easy to troubleshoot for most people.

Try completely logging out of your Apple ID/Account, everywhere (every setting/option where you can do so), on both of your devices.

For example, on iOS, you should try signing out from iCloud, iMessage and FaceTime:

• Settings → iClound → Sign Out
• Settings → Messages → Send & Receive → Apple ID: ... → Sign Out
• Settings → FaceTime → Apple ID: ... → Sign Out

Then try logging back into your Apple ID/Account on them and setting it up again.

Hope this helps :)

-James