iPhones on Sprint and EE can now use Wi-Fi to place and receive calls.
The service, simply called Wi-Fi calling, was rolled out on Wednesday for the iPhone 5, iPhone 5S, iPhone 5C, iPhone 6 and the iPhone 6 Plus.
Wi-Fi calling means you can use your wireless network for talking, instead of the regular cellular network.
Both carriers say the feature is available immediately for people who have updated their phones and downloaded the new carrier settings profile that pops up.
EE is limiting the number of iPhones able to register for Wi-Fi calling to 100,000 per day, says Macrumours, so there may be a waiting period for some users.
This is a great feature for people who have a limited calling plan, or whose house or apartment has cellular blind spots. Those with limited calling plan can switch to Wi-Fi calling for an abundance of free talking minutes, while those with blind spots no longer need to worry if their call will drop due to bad signal.
Sprint's iPhone customers will start receiving the software update as soon as today, though it's likely you'll get it "over the next week or so," according to a Sprint press release.
iPhone is now part of a list of 25 Sprint handsets which have incorporated Wi-Fi calling.
Wi-Fi calling was a feature Apple released back in September with the iOS 8, but the only US carrier to support it so far has been T-Mobile.
Both AT&T and Verizon have said it's coming to their networks this year.