For nearly two decades, your iPhone has been a bit of a walled garden. When you wanted to make a call or send a text, Apple’s own “Phone” and “Messages” apps were your only real options. But that’s changing, especially if you live in Europe. Starting with iOS 26, Apple is opening up these core communication channels to outside app developers.
This is a big deal. For the first time since the iPhone launched 18 years ago, users in the European Union will have a choice. Imagine using a third-party app not just for internet calls, but for your regular SMS, MMS, and even modern RCS text messages. You’ll also be able to pick a different app to handle your mobile phone calls.
How Third-Party Apps Get In
Apple has built new tools for developers to make this happen. One of these is called TelephonyMessagingKit. This framework lets third-party apps send and receive messages using standard mobile networks. That means SMS, MMS, and the more advanced RCS messages are all fair game. This information popped up in Apple’s developer documents for the iOS 26 beta, which was shown at WWDC 2025.
Along with this, Apple is adding a new setting for a “default calling app.” This means you can choose an app to replace Apple’s own Phone app. If you tap a phone number, it will open directly in your chosen app, whether it’s for an internet call (VoIP) or a regular call through your mobile network. This new default app will also see your call history, like who called you and when. You can find more details in Apple’s developer documentation about TelephonyMessagingKit and preparing your app to be the default dialer app.
There’s a catch, though. These new features, including the TelephonyMessagingKit and the ability to set a default calling app, are only for iPhone users in the European Union. Developers testing these features must also be located in an EU member country.
The Hand of Regulation
This move seems to be Apple’s way of responding to the European Union’s Digital Markets Act (DMA). The DMA aims to make big tech companies open their platforms more. Even though this specific change isn’t in Apple’s most recent official compliance plan, it fits the spirit of the law.
Apple has already made some concessions due to the DMA. For example, iPhone users can now pick different default apps for things like web browsing or email. However, mobile communication services like RCS were not part of that initial openness. Now, with the exception of the Phone and Settings apps, almost all of Apple’s pre-installed apps can be removed from the system.
Apple started supporting RCS messages with iOS 18. They’ve also promised to add end-to-end encryption for RCS soon. Interestingly, Apple’s iMessage service avoided the EU’s forced opening. Regulators decided that iMessage wasn’t a “core platform service” for businesses to talk to customers.
One final note on RCS: for it to work on your iPhone, your mobile carrier needs to support it. Apple has a page on its website listing which carriers in each country support RCS on iPhones. Unfortunately, not all carriers around the world have enabled it yet.