The deposit (or down-payment in Sprint's case) is all credit based. And it does vary. If it's a new line, it is simply credit based. If it's an upgrade, it's somewhat credit based and also based on your account history as well. If you have a history of missed payments...chances are there will be a down-payment required, as Sprint would view you as basically a liability. I've see down-payments range anywhere from $50 to $400. However with the iPhone 10 being more expensive, the down-payment could potentially be as high as $600. Are you upgrading or is it a new line being set up?