Wi-Fi Calling lets your phone make calls and send texts over Wi-Fi instead of a cell signal. It's built into your phone, free for calls to US numbers, and comes in handy in campus buildings where cell coverage gets spotty. Once it's on, your phone switches automatically whenever Wi-Fi is the stronger option.

iPhone

1. Open Settings.
2. Tap Cellular, then Wi-Fi Calling. (On some models it's under Phone instead.)
3. Turn on Wi-Fi Calling on This iPhone.
4. If prompted, enter or confirm your emergency address. This is used if you ever call 911 over Wi-Fi.

Android

Menus vary a little by phone maker, but the setting is usually here:

1. Open the Phone app.
2. Tap the three-dot menu, then Settings.
3. Tap Calls or Calling accounts, then Wi-Fi Calling.
4. Turn it on. If prompted, enter or confirm your emergency address.

Can't find it? Search "Wi-Fi Calling" in your phone's Settings search bar.

A note on your carrier

Wi-Fi Calling is a carrier feature, so it must be included on your plan. Most are, and it's usually on by default or one toggle away. If the setting is missing or won't turn on, check with your carrier:

• Verizon
• AT&T
• T-Mobile