Apple has added an “iPhone Handoff” feature to iOS 27 that lets two iPhones use the same phone number. On Sept. 21, IT outlet Engadget reported that the feature allows calls and messages on the same number without running two iPhones under separate carrier accounts.

The feature was briefly shown at WWDC and later introduced in more detail at the “Surprise and Shine” event held on Sept. 9. Once setup is complete, it can be used by simply unlocking the iPhone to be used. Dynamic Island shows a notification that iPhone Handoff is activated.

Users can place and receive calls on the same number on both iPhones, and send and receive messages. A payment card added to one device can be used on both. Most apps and iCloud also stay linked without interruption.

There are requirements. Both devices must run iOS 27 or later and be connected to the same Wi-Fi network. Users must also sign in to iCloud, FaceTime and iMessage with the same Apple account. One phone is set as the primary iPhone and the other as the secondary iPhone, with the primary managing the main eSIM and carrier settings. If both devices use supported carriers, each can also use its own eSIM.

There are not many supported carriers yet. So far, support has been confirmed only for U.S. carrier T-Mobile and Germany’s Telekom. T-Mobile charges an additional $5 per month for the feature.

There are also limitations. The carrier must support iPhone Handoff, and a connected Apple Watch does not switch between the two iPhones. Some Wallet items, such as IDs and passes, also do not work. When changing to a new iPhone, the eSIM must be moved to the new device. To turn off the feature completely, users must contact their carrier.

iPhone Handoff is not a feature every user needs. It can be used when running both devices while moving from an existing iPhone to a new iPhone, when carrying an older or less expensive device while traveling, or when separating work and personal devices.