I use my Galaxy S4 as one of the lines on my son's TMobile One plan. I just bought a new locked TMobile Galaxy S6. I want to move my Tmobile account and data from my old S4 to the new S6. I want to buy a SIM card on Ebay. How do I be sure to get the correct one?
I know I should NOT get a prepaid one.
Should it be activated or unactivated?
My phone is locked.
Also, do I get one that is called a replacement or not?
What does that indicate about which SIM card to buy?