Can a realtor sign a sales contract without a complete listing agreement? ("Broker") beginning (date).A listing agreement is a legally binding contract between the seller (you) and the real estate brokerage that helps you sell your home. Listing broker or mutually agreed location. When Completing the Complaint Form. Provide a written explanation of the exact nature of your complaint. And the buyer in a real property transaction. What is a listing agreement? Find out why you should choose C21.