Illinois Denial of Parentage is a legal procedure used to establish paternity, or a parent-child relationship, in the state of Illinois. It is typically used when an unwed mother or father wants to establish or deny paternity of a child. This is done through the filing of a Denial of Parentage with the Illinois Department of Healthcare and Family Services (HFS). There are two types of Denial of Parentage: Voluntary and Involuntary. A Voluntary Denial of Parentage is initiated when a father or mother voluntarily signs a document in which they deny being the parent of a child. An Involuntary Denial of Parentage is initiated when a court finds that a man is not the father of a child. In both cases, the Denial of Parentage must be filed with the Illinois HFS in order for it to be valid.