Is the T-Mobile 6s plus purchased at full price through the Apple App unlocked?

[iMore Question]

I hope to take my AT&T sim card from my 6 plus and insert into the new T-Mobile 6s plus. Will this work? I have been told that the T-Mobile version is fully unlocked, while the AT&T version comes locked and must be activated with their sim card.

 

[kch50428]

Any device sold at full price should come unlocked out of the box...

 

[EmceeGeek]

Yes