01-04-2018 10:59 PM
For better clarification regarding iPhone X not being factory unlocked...
All Apple iPhone sold by Best Buy are NOT Sim-Free/Unlocked model. What Best Buy sell is universal model. Those universal model will only work with U.S. Carrier such as AT&T, Verizon, Sprint, and yes T-Mobile. Best Buy do NOT sell carrier branded iPhone X or unlocked iPhone X.
Reason why iPhone they sell are universal is because they are designed to work for one time activation to keep their inventory from overflowing. Once you activate with AT&T, it locks to AT&T. Same goes with Verizon, Sprint, and T-Mobile.
So if you buy iPhone X outright from Best Buy, yes you will be able to activate it with T-Mobile as it is supported U.S. carrier. Keep in mind, if you activate it with T-Mobile, it's going to be locked with T-Mobile. However, Best Buy is currently not selling iPhone X outright and requires activation only.
01-04-2018 11:20 PM
what you just described was not my experience.
I purchased an iPhone X from Best Buy. I activated with a Verizon SIM. I then moved my ATT SIM into it and it immediately worked with my ATT account.
01-04-2018 11:23 PM
Keep in mind, universal iPhone are designed to focus on one carrier. It may work when switching to another carrier but we never guarantee that because again, universal phone are designed to activate once to keep inventory from overflowing.
01-05-2018 12:38 AM