Congrats on your new bird! I did the same a little under a year ago. Unless I am remembering wrong, we had to send both the bill of sale 8050-2 and the registration application 8050-1. Make sure you AND any co-owners (wife in my case) have both printed and signed names on the registration form, and that the printed names and signatures match exactly, AND that you include a "title" (like "Owner") on EACH line. We got ours back for correction about a month after sending them because we did not print a title next to my wife's name.