FYI, I posted something similar before. But my brother got his final Tmobile bill when he switched all 3 of his lines to ATT for the iPhone 5. He switched over Sept 25th His bill runs from the 8th of the month until the 7th of each month. His bill is usually $200. So T-mobile basically ripping him off $100 for the half month he didn't use. Funny how they (and other carriers) pro-rate partial months when you sign up for service. But they don't pro-rate service for the final month.