I have done several Trade Ins with Samsung here is what I do to guarantee a worry free trade in you just have to have a box a good size for the phone to fit into it doesn't have to be the original box or the box of your new phone any box that is sufficiently sized for your trade in device will do just for good measure I take several picture of the trade in device as proof of quality of the device before packaged and shipped then I do record myself packaging the phone and sealing the box make sure your also put in your trade in paper it is usually attached to the shipping label samsung offers you. If you do these things you should have no problems I know taking a video may seem excessive however I have had an experience where my trade in device was stolen from the packaging during shipping and taking a video saved me a big headache and proved I was not liable for losing the device
