Cellular for Apple Watch
I want cellular on my Apple Watch when my phone is off I want my watch to work
Question marked as
Did you buy an Apple Watch with GPS+Cellular? If yes you will have a red ring on the Digital Crown. If you have it check with your cell service provider and see if they support the Apple Watch and if they do start a new line to set it up.
If you do not have the red ring you have a GPS only watch. You would need to buy a new watch with cellular hardware to use it. P.S. if your iPhone is turned off even the cellular watch will not be able to send/receive SMS texts.