Apple is preparing a multi-device capability called iPhone Handoff in iOS 27 that allows users to keep a single phone number while moving between two iPhones. The feature was briefly mentioned on a slide during the WWDC 2026 keynote in June with zero explanation from Apple. Detailed mechanics of the capability later surfaced through a demo video created using two simulated devices inside Xcode 27’s Device Hub.
iOS 27 Introduces iPhone Handoff to Share One Number Across Two Devices
The system is designed so that a user designates one handset as the main device and keeps their primary eSIM on it. The second phone is assigned as a companion device and receives its own companion eSIM tied to the same phone number and carrier account. Under this approach, the phone number follows whichever iPhone is unlocked and in active use, switching automatically rather than ringing on both devices at once. A Dynamic Island notification can appear when the number transfers between the two handsets.
Setup and Technical Mechanics
Configuration for the capability lives in Settings under the Cellular menu, directly below “My Number” for each line that supports it. Selecting the option reveals a screen explaining that the phone number will switch to whichever iPhone the user unlocks. The companion iPhone is provisioned with its own IMEI and ICCID, meaning the phone number floats between two distinct eSIM profiles rather than cloning a line or requiring physical SIM card swaps.
Cellular settings remain locked to and managed on the main iPhone throughout the process. Meanwhile, location sharing updates dynamically to follow whichever device is actively holding and using the phone number at that time. The underlying method functions similarly to how cellular Apple Watch models share a number using eSIM provisioning, drawing on principles established since the smartwatch first adopted eSIM technology in 2017.
Carrier Support and Availability Limitations
The capability requires dedicated wireless carrier support and will not be available everywhere on day one. Early code references and beta tester reports point to T-Mobile in the United States and Deutsche Telekom in Germany as the initial partners lined up for rollout. Although the configuration option appears for beta testers on supported networks, registrations have encountered hurdles, indicating carriers are still preparing their backend systems.
Both participating handsets must run iOS 27 and operate on the same wireless carrier account, meaning users cannot leverage the system to use two phones while paying for only a single line.
Practical Use Cases and Expected Launch
The addition offers a practical utility for individuals who regularly carry separate devices for different scenarios. Use cases include juggling a smaller iPhone and a larger one, maintaining a personal device alongside a work phone, or switching between a standard handset and a potential foldable device. It also provides an option for users who want to temporarily transition to a smaller or cheaper backup device without leaving their primary line behind.
iOS 27 has been in beta testing for roughly three months and is expected to start rolling out publicly later this month, at which point further official details and carrier confirmations are anticipated.
