Any bookings made already remain in place and must be honored by the new owner: if the new owner does not, he or she could be sued by the vacationers for "breach of contract." The legal theory is this: you can only sell what you have. If you have entered into contracts for future rentals or bookings, what you have is a property where other people have an enforceable contractual right to stay there at some time(s) in the future. Therefore, what you have to sell is a property where the owner's rights over the property (e.g to do whatever he or she wants to do with it) are limited by the agreements to rent which he or she has already entered into.