Once Apple hands something over to the carriers, even a feature that should've been a free software perk somehow gets a price tag attached. The new iPhone Handoff feature in iOS 27 lets users switch the same eSIM number between two iPhones—sounds like a thoughtful move from Apple to save dual-device users some hassle, but US carrier T-Mobile has announced that subscribers will need to pay an extra $5 a month to turn it on.
iPhone Handoff isn't about two phones standing by at once—it's more of a "take turns" setup. Both phones can't receive calls on the same number simultaneously; you have to pick which one is active and switch whenever you like. When you switch, calls, voicemail, texts, and Find My location all automatically transfer to whichever iPhone is currently in use, and iCloud data plus third-party app content sync over too.
The setup process isn't complicated. Users can do it from an existing device's settings, or set it up right when activating a new iPhone: go to Settings, tap "Cellular," select "Set Up Cellular" or "Add eSIM," choose the corresponding iPhone, tap Continue, then choose Transfer, and follow the on-screen instructions on both devices. Once done, just unlock whichever phone you want to use. A "Switched to This iPhone" banner will pop up at the top of the screen confirming which device is currently active.
To use this feature, both phones need to be running iOS 27 and signed into the same Apple ID. It's initially only available to T-Mobile users in the US and Deutsche Telekom users in Germany. Why these two carriers got first dibs isn't explained in the materials.
iOS 27 is set to roll out starting September 14. T-Mobile's move to charge an extra $5 a month effectively turns Apple's native device-switching feature into a paid subscription add-on—whether this same charge shows up with carriers in other markets remains to be seen.
