Set up your iPhone and Mac for phone calls
To make and receive phone calls on your Mac, make sure of the following:
Your iPhone has iOS 8 or later installed. See the Apple Support article Update your iPhone, iPad, or iPod touch.
Your iPhone and Mac are on the same Wi-Fi network. See Connect your Mac to the Internet using Wi-Fi.
Your iPhone and Mac are signed in to iCloud and FaceTime using the same Apple ID. See Set up iCloud, Sign in to or out of FaceTime, and the Apple Support article Use Continuity to connect your Mac, iPhone, iPad, iPod touch, and Apple Watch.
Your iPhone and Mac have Wi-Fi Calling turned on, as described in the sections below. Wi-Fi calling isn’t available on some Mac models.
Set up your iPhone
On your iPhone, go to Settings > Phone.
Choose one of the following, depending on your carrier.
If you see Wi-Fi Calling, tap it, then turn on Wi-Fi Calling on This iPhone.
After you turn on Wi-Fi Calling, you may see an Add Wi-Fi Calling For Other Devices button. Tap it to allow calls using your other devices that aren’t on the same Wi-Fi network as your iPhone, or if your phone is off. Otherwise, you can still use your Mac to make phone calls, but your iPhone must be turned on and on the same Wi-Fi network as your Mac.
Note: Only certain phone carriers support Wi-Fi Calling for devices that aren’t on the same Wi-Fi network as your iPhone. See the Apple Support article Make a call with Wi-Fi Calling. You also need iPhone 5s, iPhone 5c, or later.
If you see Calls on Other Devices, tap it, then turn it on.
This option allows calls using your other devices that are on the same Wi-Fi network as your iPhone.
If you’re using iOS 8, go to Settings > FaceTime, then turn iPhone Cellular Calls on.
Set up your Mac
If you turn on Wi-Fi Calling on your iPhone, when you open FaceTime on your Mac, you might be asked to turn on Calls from iPhone on your Mac. If you’re not, do the following.
In the FaceTime app on your Mac, choose FaceTime > Preferences, then click Settings.
Select Calls from iPhone.
If you don’t see this option, make sure your Mac meets all of the requirements above, then open FaceTime preferences again.
If an Upgrade to Wi-Fi Calling button appears, click it, then follow the onscreen instructions.
This button appears if your carrier supports Wi-Fi Calling when your iPhone is turned off or is on a different Wi-Fi network.
If you’re asked to confirm your address for emergency services, click Update Emergency Address. (If you make an emergency call that uses Wi-Fi instead of cellular, the address you provide here helps emergency services locate you.) See the Apple Support article Make a call with Wi-Fi Calling.
You can turn off phone calls on your Mac at any time. In the FaceTime app, choose FaceTime > Preferences, click Settings, then deselect Calls from iPhone.
Enable RTT phone calls
If you have hearing or speech difficulties, or want to call someone who does, you can use Real-Time Text (RTT) for your phone calls, if your carrier supports it.
Note: To make or receive an RTT call, you must be using macOS Mojave 10.14.2 or later with Wi-Fi Calling through iPhone with iOS 12.1.1 or later. This feature is not available in all regions or supported by all carriers. Depending on your network environment, an RTT call may be downgraded to a TTY call.
On your iPhone, go to Settings > General > Accessibility.
Tap RTT/TTY, then turn on Software RTT/TTY.
When RTT is on, appears in the status bar at the top of the screen. You can choose additional options for RTT calls on your iPhone.
On your Mac, choose Apple menu > System Preferences, then click Accessibility.
Click RTT, then select Enable RTT.
Note: If you don’t see RTT, check that you’ve completed all the setup steps above. If you still don’t see RTT, it may not be supported on your Mac.
Choose additional options. For more information, click the Help button in the pane.
When RTT is enabled on your Mac, the RTT button is shown—for example, in a card in the Contacts app or in FaceTime—to indicate that you can make or receive an RTT call.