How to Fix “Cannot Turn On Calls on Other Devices” on iPhone

The “Cannot Turn On Calls on Other Devices” alert means the iPhone cannot verify a requirement for relaying cellular calls to a Mac or iPad. Check that iCloud and FaceTime use the same Apple Account, FaceTime can reach your number, and Wi-Fi and call relay are enabled. Start with the account check.

This feature relays regular cellular calls, not FaceTime audio calls. On iOS 18 and later, app settings are under Settings > Apps; on older versions, open FaceTime or Phone directly in Settings.

1. Check the Apple Account on every device

On iPhone, tap your name at the top of Settings and note the account email. Confirm that same Apple Account in Settings on the iPad and System Settings on the Mac. Check FaceTime on each device too: it can use a different account from iCloud, but call relay requires the same account for both services.

If an account differs, change the FaceTime sign-in on that device. You do not need to sign out of iCloud everywhere first. Apple’s setup guide lists the account and network requirements.

2. Turn on FaceTime and select your iPhone number

On iPhone, go to Settings > Apps > FaceTime and turn FaceTime on. Confirm the Apple Account matches, then select your phone number under You Can Be Reached by FaceTime At and for Caller ID if shown. iMessage has separate settings, so its phone-number selection does not replace this check.

If the number is missing, confirm the iPhone has an active cellular line. If FaceTime uses the wrong account, sign out of FaceTime only, sign back in with the iPhone’s account, and check again.

3. Put the devices on the same Wi-Fi network

Turn on Wi-Fi on the iPhone and the receiving device, then connect them to the same Wi-Fi network. A Mac can use Ethernet if it shares that local network. Keep the iPhone on and within about 30 feet (10 meters) while testing. If you use a VPN, make sure it allows local networking.

4. Enable Calls on Other Devices on the iPhone

Open Settings > Apps > Phone > Calls on Other Devices, enable Allow Calls on Other Devices, then enable each Mac or iPad. On older iOS, open Settings > Phone. If a device is missing, finish its FaceTime setup and check this list again.

An activated carrier plan is also required. If the main switch stays unavailable, confirm the iPhone’s cellular service is active; contact your carrier if regular calls are failing too.

5. Enable iPhone calls on the receiving device

On a Mac

Open FaceTime, choose FaceTime > Settings, confirm the same Apple Account, and select your number under You Can Be Reached for FaceTime At and Start New Calls From. Then select Calls from iPhone. Keep the Mac on the same local network as the iPhone.

On an iPad

Open Settings > Apps > FaceTime, enable FaceTime, confirm the same account and selected phone number, then turn on Calls from iPhone. If the option is missing, complete iPhone setup and check again.

6. Refresh the setup and test a regular call

Update the iPhone and receiving devices, restart them, then recheck the switches. On iPhone and iPad, look under Settings > General > Software Update. This can help when FaceTime settings or the device list will not refresh.

If the FaceTime account is wrong or the option still will not activate, sign out of FaceTime on the affected device, restart it, and sign back in with the iPhone’s Apple Account. Recheck the phone number and Calls from iPhone. Then place a regular cellular call to the iPhone and see whether the Mac or iPad shows the incoming-call notification.

To use other devices when the iPhone is off or on a different network, you may need carrier-supported Wi-Fi Calling. See Apple’s Wi-Fi Calling instructions and confirm availability with your carrier.