Following T-Mobile and Sprint, AT&T has just enabled a much-anticipated feature called Wi-Fi Calling for people who have an iPhone 6, 6 plus, 6s, or 6s plus running iOS 9.x on AT&T.

From AT&T’s web site…

With Wi-Fi Calling, you can talk and text over Wi-Fi when cellular coverage is limited or unavailable. For example, some indoor locations may be difficult for even a strong cellular signal to reach. Now, with a Wi-Fi connection, you can talk and text in those hard-to-reach places.

• Wi-Fi Calling is easy to set up and use.
• Once you set up Wi-Fi Calling, your phone automatically detects when to use it. Wi-Fi Calling will only be used if cellular coverage is weak or unavailable.
• It works with your AT&T mobile number and compatible device—no new number or app required.

Once you set up Wi-Fi Calling on your phone, you’ll be able to enjoy the benefits. Just follow the steps in your phone’s settings to get started.

• Make and receive unlimited domestic calls within the U.S., Puerto Rico, and U.S. Virgin Islands at no additional charge.
• International long distance rates apply for calls made to international numbers.
• Text messages sent or received using Wi-Fi Calling are counted and charged under your existing rate plan.

Here is a link to AT&T’s FAQ page on Wi-Fi Calling that should answer any questions that you might have.

• Are you a T-Mobile subscriber? Here is a link to T-Mobile’s Wi-Fi Calling FAQ page.
• Are you a Sprint subscriber? Here is a link to Sprint’s Wi-Fi Calling FAQ page.
• Are you a Verizon subscriber? Verizon Wireless has released a new version of its Verizon Messages app, enabling users to make Wi-Fi calls from their newer iPhones.