I just set this up today. I have a Google pixel phone with Google Fi and wanted a standalone LTE watch with a separate phone number to my phone.
Steps:
- I purchased a Watch 4 LTE at Samsung store then walked to the nearest T-Mobile store. At that point I was not a T-Mobile customer.
- I asked to get the $5 per month Wearables 500mb plan (unlimited talk, messages, 500mb data). They did a trans union credit check and set it up. It took about 15 minutes.
-They took my watch's EID number to connect the watch to my new plan
-I then set up my T-Mobile online account and added the new phone number of the watch
- Once logged in to my T-Mobile account online, I got the esim QR code data from here:
https://www.t-mobile.com/support/devices/t-mobile-esim#heading4. The activation code is what the QR code contains, this is what you need to paste into the watch: LPA:1$T-MOBILE.GDSB.NET$
- Next step is to enable access to the watch's esim as standalone is not officially supported by Samsung:
- Open Galaxy Wearables app on your phone; go top left menu and click "About Galaxy Wearable"; tap "Galaxy Wearable" text about 5 times to open the developer options; Tap "Test ESIM Feature"; Tap "Current QR TestMode : off" to turn it on.
- In Wearables App go to "Watch Settings" and tap "Mobile Plans" and tap QR scanner; enter activation code manually - paste the esim qr data obtained in above step
-Watch will connect to T-Mobile and ask to download something to finish setup.
- In Google Messages on the watch I can switch between my pixel phone number and watch number to view, send and receive texts.