I've always appreciated the AT&T employees that are members on this board for answering questions about how to do an upgrade swap with another person on a family plan. Perhaps we can even make this designated thread since I know a lot of people are asking these types of questions in many different threads. Here's my scenario: I'm on a family plan. I used my sisters upgrade to buy the 4S. I currently have iPhone 4. My sister uses the ancient Samsung phone that has a normal SIM. I will sell my iPhone 4 and she plans to keep existing Samsung phone. How do I go about doing an upgrade swap without having to call AT&T? Is it just about putting my iPhone 4 micro-sim into her new iPhone 4S before I activate it through iTunes?