FaceTime phone call requirements
To make and receive phone calls on your Mac (OS X 10.9 or later), make sure of the following:
- Your iPhone has iOS 8 or later installed. See the Apple Support article Update your iPhone or iPad. 
- Your iPhone and Mac are on the same Wi-Fi network and connected to the internet. 
- You’re signed in to the same Apple Account on your Mac and iPhone. See the Apple Support article Continuity features and requirements on Apple devices. 
- Your iPhone and Mac have Wi-Fi Calling turned on. Wi-Fi Calling isn’t available on some Mac models.