iPhone Handoff is a new Apple feature that lets customers use the same T-Mobile phone number across two compatible iPhones and choose which phone is active at any given time. The secondary iPhone works seamlessly, including essential T-Mobile services like calls, texts, data, mobile hotspot, international roaming, Scam Shield and T-Satellite on eligible plans, allowing customers to get the most from two devices without clunky handoffs or the hassle of managing another number (like using a secondary phone for work, travel, fitness, gaming, superior camera and more). iPhone Handoff is available on any iPhone with iOS 27 via iPhone settings and ready to use from day one on the new iPhone 18 series. T-Mobile is introducing the feature at $5/month.

To use iPhone Handoff, you'll need two iPhones (tablets and other devices aren't eligible), both running the current iOS software, and signed into the same Apple ID and iCloud account with two-factor authentication turned on. Each device also needs a passcode or Face ID set up, and you'll need an eligible T-Mobile postpaid account. You'll set it up directly on the iPhone that doesn't have your primary eSIM, and activation happens entirely on-device, no store visit or call required.

No, it's an iPhone-only feature, and both iPhones need to have the same Apple ID and iCloud account with 2FA, PIN or FaceID, and iOS 27. The second phone should not have any other service attached to it.

The feature is designed to travel with you if your primary plan includes international roaming. For those customers, the secondary phone gets unlimited calls, messaging, and 5GB high-speed data in Canada and Mexico then unlimited 128kbps and $0.50/min calls, unlimited messaging, and 5GB highspeed data in 11 European countries then unlimited 256kbps in 215+ countries and destinations. If you need additional international data, you may use your primary phone.

Like a smartwatch, iPhone Handoff uses eSIM in each device and a separate assigned billing phone number on your T-Mobile account. You can activate iPhone Handoff when setting up your new iPhone or anytime from the Settings menu. The on-device activation process will ensure both eSIM and the assigned billing phone number for the secondary phone are correctly set up.

Like a smartwatch, your secondary phone will use the same phone number to send and receive calls and messages, but it will not use the same plan. 

Your secondary phone plan supports unlimited calls, messaging, and data within the US with 50GB of premium data and unlimited 3G mobile hotspot. If your primary plan includes international roaming, your secondary phone includes unlimited calls, messaging, and 5GB high-speed data in Canada and Mexico then unlimited 128kbps and $0.50/min calls, unlimited messaging, and 5GB highspeed data in 11 European countries then unlimited 256kbps in 215+ countries and destinations. If your primary plan has T-Satellite, you can also use it on your secondary phone (compatible device required).

At launch, this feature is only available to T-Mobile postpaid consumer or sole proprietor accounts.

At launch, this feature is only for use with one active number/eSIM on both your primary and secondary phones.