How To Get An Apple Watch Set-Up With T-Mobile Service

In order to set up your Apple Watch with T-Mobile service, you’re going to need an iPhone that is simultaneously connected to T-Mobile for its data plan and paired with the Apple Watch. The vast majority of the set-up process is performed on the iPhone.

1. Ensure that your T-Mobile-connected iPhone and your Apple Watch are paired and have the most recent versions of iOS and WatchOS installed respectively.
2. Open the Watch app on your iPhone.
3. Tap My Watch in the top-left corner.
4. Scroll down and tap Cellular.
5. Select Set Up Cellular.
6. A pop-up screen may prompt you to unlock your Apple Watch. If not, skip this step. If so, enter your passcode into your Apple Watch to unlock it. Then, select OK on the iPhone and tap Set Up Cellular again.
7. A page allowing you to add a T-Mobile data plan to your Apple Watch will appear. Select Enter the last four digits of the primary account SSN. Then, type in the last four digits of the T-Mobile plan primary account holder’s SSN.
8. Tap Continue.
9. A screen displaying T-Mobile’s service agreement will display. After reading it, check the box next to By clicking here, you accept these Service Terms.
10. Tap Continue.
11. Tap Continue setup.
12. Your Apple Watch now has T-Mobile cellular service enabled through an additional line on your existing data plan.

After this process is complete, your Apple Watch will automatically connect to T-Mobile’s cellular service when a Bluetooth or Wi-Fi connection is unavailable. If you want to replace an Apple Watch with a new one on the same data plan, simply enter the Watch app’s cellular settings on your iPhone, remove the old Apple Watch from the plan, and follow the aforementioned steps to activate your new Apple Watch.