iOS 27 will let users maintain a single phone number across two iPhones simultaneously through a new “iPhone Handoff” feature that assigns a companion eSIM to the second device.
A MacRumors forum member demonstrated the feature, using Xcode 27’s Device Hub simulator, showing exactly how setup and switching will work when iOS 27 ships later this month. This capability requires both the iOS 27 feature to be available and carrier-level support to route phone numbers between devices.
How iPhone Handoff Setup Works
Users configure the feature in Cellular Settings, designating one device as primary and the other as companion. The main eSIM remains active on the primary iPhone, while the companion iPhone receives its own eSIM tied to the same phone number. Calls and messages route to whichever device is currently in active use without manual switching or additional configuration once setup completes.
All cellular settings remain managed through the main iPhone, including which device actively holds the phone number at any given moment. Location sharing defaults to whichever iPhone is currently active on the line, a detail that matters for Find My and location-dependent services like Apple Maps.
The feature requires carrier infrastructure to route the phone number between two separate eSIMs. T-Mobile in the U.S. And Deutsche Telekom in Germany are mentioned as potential early adopters, but broader carrier support is not clear yet. This dependency mirrors past Apple feature launches like visual voicemail and eSIM support, which saw carriers adopt at different speeds and sometimes with regional restrictions or additional fees.
The fragmented carrier market could create a two-tier experience where users on early-adopting carriers enjoy smooth switching while others face limitations or delayed rollout. International users and those on smaller carriers may find the feature unavailable for months or longer after iOS 27 launches.
Users can pair a high-end iPhone Pro or Ultra with a more compact or budget-friendly iPhone for different scenarios. A traveler might keep a less-valuable phone as a “knockaround” device for risky environments like beaches or crowded transit while the main device stays secure elsewhere. Business professionals could separate work and personal activity without carrying two separate phone numbers.
iOS 27 ships by end of September 2026, with carrier rollout details expected at launch. Official documentation should follow shortly after, though the full scope of carrier support may not be known until release day. Early adopters on T-Mobile or Deutsche Telekom will likely be the first to test the feature in production.
