iOS 26 was announced nearly a month ago, but there is one change related to phone calls and messages that flew under our radar until now.
As reported by German tech news website Heise last month, Apple has introduced new APIs that allow for developers to implement support for making cellular phone calls and sending and receiving SMS/MMS/RCS messages in third-party apps, but only iPhone users in the EU will be able to take advantage of this functionality.
These carrier-based capabilities have always been limited to Apple's Phone and Messages apps, so this is a big change. Apple likely expanded these features in response to current or anticipated regulations under the EU's Digital Markets Act.
Third-party apps could already offer Wi-Fi calling and messaging.
Apple says iPhone users in the EU will only be able to make cellular phone calls and/or send and receive SMS/MMS/RCS messages in a supported third-party app when they have selected the app as their default dialing app and/or default carrier messaging app on iOS 26. Otherwise, the functionality is not enabled.
These capabilities will not be available in third-party iPad apps, or in iPhone apps running on macOS or visionOS, according to Apple.
For the cellular phone call functionality in particular, even the developer of an app requires an Apple Developer account registered in the EU. Given how locked down these capabilities are, do not expect them to expand to the U.S. or elsewhere any time soon.
iOS 26 is currently in beta. The update should be released to the general public in September.
Source: Macrumors