An Illinois Class S Affidavit is a type of legal document used in the state of Illinois to transfer ownership of a motor vehicle. This document is often used when transferring a vehicle from one person to another without involving a title or registration. The affidavit must be completed by both the buyer and seller and be notarized. There are three types of Illinois Class S Affidavit: 1. Transfer of Title Without Consideration: This affidavit is used when transferring the title of a vehicle without any exchange of money. This is common when transferring ownership of a vehicle between family members. 2. Transfer of Title with Consideration: This affidavit is used when transferring the title of a vehicle with an exchange of money. This is common when selling a vehicle from one person to another. 3. Vehicle Identification Number Affidavit: This affidavit is used when a vehicle does not have a title and the VIN is not visible. This affidavit is used to prove ownership of the vehicle so that the buyer can obtain a title.