An Illinois Continued Ownership and Use affidavit is a legal document used to provide evidence that a person has continued to own and use a piece of property in the state of Illinois. This document is often used for tax purposes, as it allows the taxpayer to avoid paying taxes on any appreciation in the value of the property. There are two types of Illinois Continued Ownership and Use affidavit: 1) an Illinois Residential Continued Ownership and Use affidavit, and 2) an Illinois Commercial Continued Ownership and Use affidavit. The Residential affidavit is used to document the continued ownership and use of a residential property that the taxpayer has owned and used for more than three years, while the Commercial affidavit is used to document the same for a commercial property. Both affidavits must be signed by the taxpayer and notarized, and must include details such as the address of the property, the date of its purchase, and the date of its continued use.