This is probably a stupid question, but here goes. Just received my iPhone 6S, upgrading from an iPhone 6 via Jump On Demand. The new phone came with a T-Mobile SIM card, which was a surprise because I was expecting it would be empty. Are you supposed to swap in the SIM card from your existing phone to the new one, or does the new phone's SIM also work with my account (clone)? Weird that there is no instructions on what to do. I tried test calling from another iPhone 6, and it seems to always prefer FaceTime rather than making the call via T-Mobile voice, so it rings on both phones (and an old iPhone 5 I have It's also weird that Apple no longer includes a SIM extraction tool with phones, but I have some from my older iPhones. Thanks!