An Illinois Affidavit as to Military Service is a legal document used to verify an individual's past or present military service in the state of Illinois. It is also referred to as a “Certification of Military Service” or a “Certificate of Military Service.” This document is required by the state of Illinois for certain benefits, such as obtaining a veteran’s license plate, and is issued by the Illinois Department of Veterans’ AffairsIDEAVA). There are two types of Illinois Affidavits as to Military Service: 1. The Illinois Affidavit as to Military Service (for Illinois residents): This document is used to verify military service in the state of Illinois for an individual who currently resides in the state. 2. The Illinois Affidavit as to Military Service (for non-Illinois residents): This document is used to verify military service in the state of Illinois for an individual who does not currently reside in the state.