If you have an Apple Watch, you already know that incoming phone calls and FaceTime calls will ring on your watch alongside your iPhone, so you can answer the call and talk on your wrist, Dick Tracy style. Switching the call back to your iPhone once you’ve answered it is straightforward enough as well — simply tap the green bar that appears at the top of the home screen to open the Phone app and transfer the call to there in one fell swoop. What you may not know, however, is that you can also send calls in the other direction — transfer an in-progress call from your iPhone over to your Apple Watch.
It’s slightly less obvious how to do this, as there’s no visual indicator on the main Apple Watch screen. However, if you open the Phone app, you’ll see the telltale green bar with an in-progress call indicator right at the top of the screen above the Favorites button. Unlike the iPhone, however, there’s an extra step — tapping on the green call indicator will take you to a call in-progress screen, but doesn’t transfer the call right away — you’ll need to swipe up (or use the Digital Crown) to reveal an “Apple Watch” button that can be used to transfer the call over to your wrist.
Once you’ve done this, you can transfer the call from your Apple Watch back to your iPhone in the normal manner by tapping the green status bar that will appear on your iPhone home screen, and in fact can hand your call off between your Apple Watch and your iPhone as much as you like. Unfortunately, you’ll still need to stay in range of your iPhone even if you have a cellular-capable Apple Watch Series 3, since this method doesn’t do an actual transfer of the call; it’s more like using the Apple Watch as a remote speakerphone.