I just realized that you might be asking because you want to buy a used Tesla X.
If you buy from Tesla, they turn all options off, and they need to be repurchased even if originally were part of first owner's purchase. That means if the vehicle was purchased with FSD and Ludicrous, Tesla will turn that software and make the new owner repurchase it. :/
If you buy from a private person, all options remain as originally purchased and you need only transfer ownership information to yourself.
I think what Tesla is doing is double dipping and should be considered unethical and perhaps not entirely legal. IMHO, and I'm not a lawyer.
P.S. - I found my original bill of sale and "window sticker", and it is kinda fun to see all options were purchased. If I upgrade and/or sell the vehicle back to Tesla, I will post my VIN and a copy of what was purchased. In that way Tesla will have a harder time making the new owner re-purchase what is essentially a previously purchased software upgrade.