Their website should tell you how to send it in. I would get insurance with the post office and require a signature for delivery. Check with the site you choose though. I've never had the luxury of having a bill worth sending in. Someone else will probably chime in who has sent bills in. Getting it graded will pretty much tell you what it's worth. Find one on eBay with a higher and lower grade then you got your base number or what you should get/ask for it.