Apple is introducing a feature called iPhone Handoff with iOS 27, allowing a single eSIM phone number to be shared across two iPhones without using them simultaneously. However, T-Mobile in the US has confirmed it will charge subscribers an extra $5 a month to access the feature, adding a fee to what Apple is positioning as a convenience upgrade. The tool will initially roll out to T-Mobile customers in the US and Deutsche Telekom customers in Germany, with wider availability likely to follow.

With Handoff enabled, users can switch which of their two iPhones is active at any time, and calls, voicemail, messages, Find My, iCloud data and third-party app data will sync automatically to whichever device is in use. Setup is done via the Cellular section in Settings, either on an existing device or when activating a new iPhone, and both handsets must run iOS 27 and share the same Apple ID. iOS 27 is set to launch on 14 September.