That is a used iPhone with multiple reviews saying it was locked when it arrived e.g.:
> Phone was Locked
> I bought this phone for my son so that he can reach me while he's at school. The product description for this phone said "unlocked" which was a major reason I chose it. It is a beautiful phone and like new. However, I quickly realized that it was an AT&T phone meaning it is locked. That was disappointing because I had planned on using Verizon. I didn't want to go through the trouble of returning it and waiting for a different phone, so I decided to keep it and get an AT&T plan.
And:
> Locked preowned phone. Garbage
> Zero stars. Bought a preowned Iphone X that was still locked from previous carrier. Could not be hooked up to new carrier.
Terrible customer service, no resolution of our problem. Spent 2 hours on the phone with best buy, apple, and sprint.
Best Buy sold us junk. DO NOT BUY PREOWNED FROM HERE.
And:
> Unusable phone (and arrived late)
> Not only did the phone arrive 3 days late, it arrived locked and unusable. Was not able to activate with tmobile as they said the phone was not in their system.
Best Buy don't sell unlocked new iPhones, never have. And all of their used inventory has similar reviews.
> Phone was Locked
> I bought this phone for my son so that he can reach me while he's at school. The product description for this phone said "unlocked" which was a major reason I chose it. It is a beautiful phone and like new. However, I quickly realized that it was an AT&T phone meaning it is locked. That was disappointing because I had planned on using Verizon. I didn't want to go through the trouble of returning it and waiting for a different phone, so I decided to keep it and get an AT&T plan.
And:
> Locked preowned phone. Garbage
> Zero stars. Bought a preowned Iphone X that was still locked from previous carrier. Could not be hooked up to new carrier. Terrible customer service, no resolution of our problem. Spent 2 hours on the phone with best buy, apple, and sprint. Best Buy sold us junk. DO NOT BUY PREOWNED FROM HERE.
And:
> Unusable phone (and arrived late)
> Not only did the phone arrive 3 days late, it arrived locked and unusable. Was not able to activate with tmobile as they said the phone was not in their system.
Best Buy don't sell unlocked new iPhones, never have. And all of their used inventory has similar reviews.