Apple’s iPhone Handoff Lets One Number Move Between Two iPhones

Both devices must run iOS 27 and be registered under the same Apple ID to use Apple’s upcoming iPhone Handoff feature. The service will arrive with iOS 27 on September 14 and allows a single phone number to be shared across two distinct iPhone handsets.

Users can activate the connection during the initial setup of a new device or through the settings of an existing iPhone. In the iOS Settings app, they must open the “Cellular” menu, choose “Set up Cellular” or “Add eSIM,” and select the designated secondary iPhone. After tapping “Continue” and “Transfer,” they complete on-screen prompts shown on both devices.

The feature is tied to Apple’s longer shift from physical SIM cards to digital eSIM standards. Apple added eSIM support alongside traditional nano-SIM trays in 2018 with the iPhone XS, XS Max, and XR. In September 2022, the company removed physical SIM card trays from every iPhone 14 model sold in the U.S. market, requiring domestic carriers to optimize their digital activation pipelines.

Once the service is configured, unlocking the preferred handset switches its active status. A notification reading “Switched to this iPhone” appears at the top of the screen to confirm that cellular registration has moved to that device. Users cannot have both iPhones actively stream cellular data or receive calls at the same time; they must select which handset is active.

The rollout will begin through exclusive partnerships with Bellevue, Washington-based T-Mobile in the United States and Deutsche Telekom, T-Mobile’s parent company, in Germany. The service is called “iPhone Handoff,” and Apple and its European and American carrier partners will use it to manage single-number identities across multiple smartphone form factors.

When one phone is selected, the user’s primary cellular functions—including incoming and outgoing calls, voicemail, text messages, and Apple’s Find My tracking network—automatically transfer to the active handset. Cloud-based data, third-party applications, and user settings continue syncing between both iPhones through Apple’s iCloud infrastructure.

T-Mobile subscribers who use iPhone Handoff will pay an additional $5 per month. The charge follows existing carrier practices for secondary connected devices, including the standard $10 monthly fees often charged for cellular-enabled smartwatches.

The fee also represents a change for T-Mobile, whose brand was historically built around its “Un-carrier” campaign. Former CEO John Legere launched that initiative in 2013 to eliminate unexpected consumer fees, long-term contracts, and device subsidies. Under current CEO Mike Sievert, T-Mobile has gradually adjusted its pricing structures and introduced new service charges.