iPhone Handoff, new in iOS 27, lets you use the same phone number on two iPhones and switch between them without a carrier call. Only one device is active at a time, so it’s not the same as running two independent lines, and it currently costs $5 a month through T-Mobile in the US, the only carrier that reportedly has support so far.
Both iPhones need to run iOS 27 or later, connect to the same Wi-Fi network, and sign in to the same Apple Account for iCloud, FaceTime and iMessage.
How to Set Up iPhone Handoff on Two Existing iPhones
- Place both iPhones next to each other and unlock the one that already has your number active.
- Open Settings and tap Cellular.
- Tap iPhone Handoff, or Set Up Cellular if that option doesn’t appear yet.
- Choose Use Number on This iPhone and Another, then tap Continue.
- Follow the prompts on both devices to finish setup, and choose which iPhone becomes your main device, ideally the one you use most.
Once setup is complete, unlocking either iPhone makes your number active on it. A “Switched to this iPhone” message confirms the change.
What Moves Between Your Two iPhones
Calls, voicemail, messages across iMessage, RCS, SMS and MMS, and your Find My location all move to whichever iPhone is active. Data synced through iCloud updates across both devices automatically, and most third-party apps work on either phone, though some may need a separate sign-in or take a moment to sync.
What Stays Tied to Your Main iPhone
- Carrier account management, including Call Forwarding and Caller ID
- An Apple Watch, which does not automatically switch its pairing when your number moves
- Some Wallet items, including certain transit passes and IDs, which may only work on one device at a time
Pair your Apple Watch to whichever iPhone you expect to carry most often, since it won’t follow your number to the secondary device.
The setup itself is quick once both phones are in front of you, and the $5 monthly fee is a fair trade for anyone who genuinely splits time between a work and personal iPhone.
