Illinois Class 4 Not-For-Profit affidavit Instructions are the guidelines for filing a Class 4 Not-For-Profit affidavit in the state of Illinois. This affidavit is used to declare a not-for-profit organization as an Illinois domestic corporation. There are two types of Illinois Class 4 Not-For-Profit affidavit Instructions: 1. Not-for-Profit Corporation — This affidavit is filed when a not-for-profit organization is organized as a corporation and is seeking to receive tax-exempt status. The affidavit must include the name of the corporation, the address of the principal office, the names and addresses of the directors, the purpose of the corporation, the type of not-for-profit organization, and the signature of the incorporated. 2. Not-for-Profit Limited Liability Company — This affidavit is filed when a not-for-profit organization is organized as a limited liability company and is seeking to receive tax-exempt status. The affidavit must include the name of the limited liability company, the address of the principal office, the names and addresses of the members, the purpose of the limited liability company, the type of not-for-profit organization, and the signature of the organizer.