You can obtain the Residential Real Property Disclosure Report form from the Illinois General Assembly website. A For Sale By Owner contract Illinois must include: 1.The Purchase Price, 2. An Illinois purchase agreement is a standard contract for selling real estate from one party to another. Illinois requires those selling FSBO to fill out and file many documents and forms. Several of these documents are legally binding agreements. This means only residential real estate with a singlefamily residence, or up to fourunit multifamily homes must fill out that 2022 form. How do I fill this out?