I tried searching for this to no conclusive answer so I'm posting it. I am going to cancel my tmobile, because of their rate change to void the ETF, and then switch to att and iphone. I'm curious the correct order. Given that tmobile will put up a fight, I'm sure. I don't want to start ATT till I know tmobile is cancelled with a note for no ETF. However, i need to keep my number. Will tmobile, if i tell them i want to cancel on a certain date or at the end of my current bill, keep that open until I port to att. I imagine they will put the ETF and all service charges on, then credit the ETF. Thoughts? Experiences? Cheese?