I own an iPhone 5s with iOS 8 (or above) locked to T-mobile carrier (USA), although I do not have the original sim. I am stuck on the setup page since I had reset the iPhone to factory setting and it keeps asking me for the original sim which i do not have. (IMEI checks does show that the iPhone is already activated as it was used on the original sim before) However, i put in a new sim from optus carrier (i am now in australia) and the network shows signal with 4G data, I have attached an image of it. Now my question is, is the iPhone sim locked? Can i just unlock the sim or would i have to unlock the iPhone?