Based on my understanding the T-Mobile iPhone, when bought from the Apple Store directly, is unlocked. I bought four for my family and all of them were unlocked as expected and work fine with a non T-Mobile sim card. However, during the initial setup process, they all displayed a screen showing the IMEI and serial number stating pending activation. Could someone with more knowledge on the subject explain why, if unlocked, would the screen be displayed when the iPhone was initially turned on with a non T-Mobile sim? The phones work fine, just curious. Thanks!