A One Time Showing Agreement is a commission agreement signed between a buyer's agent and a seller for specific named buyers. A OneTime Showing Agreement form is a legally binding agreement between the buyer's broker and the homeowner listing the property for sale.The property and improvements which the Seller is agreeing to sell and which the Purchaser is agreeing to purchase is known as. A listing agreement is a legally binding contract between the property owner and a real estate agent. What is included in a listing agreement? This guide will help you to understand the changes and the proper way to fill out the forms. Addendum is not a mandatory Texas Real Estate Commission form. Izen is an attorney who holds a license to practice law in Texas. Cook is a Montana resident, who, at one time, held a license to sell real estate there. A copy of one photo ID from List A must be provided along with an Occupancy Affidavit (the affidavit is provided within the online application).