If you pay month-to-month credits will only roll-over if you put a minimum on. In this case, $20. Minutes are charged differently, depending on the plan. YOu can change the plan if you want. All I need to do is transfer reponsibility over to the new owner. You have no obligation to pay shit if you don't want to. You'll be able to use the phone as soon as you put credits in it. YOu can even buy phone cards at the corner store and enter in a code for the credits. If you pay for a full year ($100?), the credits stay with your account. I don't think you can transfer credits to another phone. You could ask Roger though.