Not sure how that would work if you signed up for LTE service, but canceled to return your watch. May depend on your carrier. I didn’t sign up with ATT until I had my LTE watch for a few days. During signup, it said I would get credited for the one-time activation and 3 months free sometime within the first 3 bill cycles. Not sure what happens if you cancel. Indeed my first bill shows no credits and has the $25 and $10/mo charge. So I guess worst case is you might have to pay $35 to try it out on ATT.