From what I’ve read, generally, you can put an AT&T sim, that had been originally used in an iPhone, into an unlocked android device with GSM, and it’ll work on that data plan. I want to use my iPhone X sim in an unlocked Galaxy Note 8; however, my data plan is a grandfathered iPhone unlimited data plan, and I don’t want to do anything to cause AT&T to void or cancel the plan. Various AT&T reps give me conflicting information. If anyone here has experience or knowledge with this, I’d appreciate your help.