Each provider occasionally makes minor updates to the sims so you'll want to use the new SIM if you've been using an old one for a while. It's usually free so done see why you won't want to just swap it.I have AT&T, if I take my sim card out of my 5s and put it in my 6+ will it work? I know in the past if you inserted an active sim it would work in any other phone.
Do you Get lte? Is the TMobile one unlocked?Yes, I bought a T-mobile 6+ and put in my AT&T sim card from my 5S. It works!
Is the Verizon one unlocked and do you get lte? Also does anyone know if this applies to the 6?The sim from my AT&T 5s is now in my Verizon 6 Plus