I just purchased 2 iPhone 6s phones for family and will be leaving this Sunday overseas. When I purchased them, the full price t-mobile version was the only one avialable so I purchased them assuming it's unlocked and should work. Now I see they just started offering a sim free 6s. Basically, the phones will be used mainly in the UAE and Jordan. Will I have issues?. I'll exchange them before I leave if I have to. I would appreciate any info.