So I am getting kicked off my parents phone plan and I want to join on with my brother/cousins. My parents phone plan is ATT, and the plan that I want to switch to it Verizon. My two year contract ends with ATT this September I believe. Am I able to seamlessly transfer to Verizon by just getting a SIM card? I want to make sure I don't lose my chance at upgrading when the new iPhone comes out in September. If I transfer say this June and lose that chance of upgrading because I switched to Verizon, I may aks my parents if I can hold off on the switch when my contract ends. If I'm able to switch in June, and then enroll in the iPhone upgrade program in September when the new iPhone comes out, I may be fine switching now. What's it gunna be?