You'll have to pay off your current tab balance. If you're wishing to keep your same plan you can get the iphone 5c on the medium tab paying $275 plus taxes out of pocket. If you're wishing the iphone 5s you'd pay $425 out of pocket. If you're wishing for a bigger substidy the 5c would be $75 out of pocket on a large tab. and $225 out of pocket for the iphone 5s. Keep in mind you'd have to choose from 1 of the large tab plans that start at $65 plus a $10 tab charge if you decide to go this route.