A quietly powerful new iOS 27 feature is coming into focus, and it looks like T-Mobile could be among the first carriers ready to actually support it when it lands.
As reported by MacRumors, the feature, called “iPhone Handoff,” lets someone designate a main iPhone and a companion iPhone, both running iOS 27, and use the same phone number across either device by switching back and forth. It’s set up through Settings under Cellular: the primary eSIM stays on the main device while the companion phone gets a linked companion eSIM tied to that same number, with cellular settings managed from the main phone and location sharing following whichever device is actively being used.
Apple briefly teased the feature on a slide at WWDC 2026 without further detail, and the mechanics only became clear after a MacRumors forum member posted a video showing the setup flow running on simulated devices.
The important caveat is that this isn’t purely a software feature: it needs carrier cooperation to function, and early signs point to T-Mobile in the US and Deutsche Telekom in Germany as the carriers most likely to support it first, even though neither has confirmed anything officially yet. If that holds, T-Mobile customers could end up being the first in the US able to actually use iPhone Handoff once it ships.
The use case is pretty relatable if you’ve ever wanted a second iPhone without juggling two numbers: a stripped-down companion phone for travel, the beach, or anywhere you don’t want your main device with all its accounts and data, while still being reachable at your usual number. iOS 27 has been in beta for about three months now and is expected to roll out publicly later this month, which should bring more clarity on carrier support at launch.
Source: MacRumors