Typically, the “buyer” in a Land Contract does not own the property or hold clear title until the entire amount due as listed within the land contract document is paid.
So the Land Contract “buyer” cannot sell the property until all payments have been made and the Deed has been revised with the county recorder to show sole ownership.
Until such a time and in most cases, only the current Deed holder can sell the home, with deference to the terms of the land contract.
To create a well-written Contract for Deed that specifies these very types of situations in writing, see Standard Legal’s Land Contract legal forms software.