An Illinois lease agreement is a contract that defines the relationship between a property owner and their tenant. The Original Agreement is on file at the Carrier's General Office.Paragraph 1-Property: Enter the premises type that is being leased. Rental Application Paperwork provided to those seeking the rental of a property for lease. Use our free, customizable Illinois lease agreement template to create a legally binding contract when you lease your Property in the state of Illinois. Use our free, customizable Illinois lease agreement template to create a legally binding contract when you lease your Property in the state of Illinois. Our Illinois lease agreement template helps landlords and tenants create clear, compliant rental agreements, covering key terms like rent and security deposits. The Illinois residential lease agreement outlines the details of a rental agreement between a landlord and tenant. Some companies offer just a lease Agreement template that the Landlord may print out and fill in. The standard template of an Illinois rental agreement form establishes the nature of the lease while stating the required details from each party.