Illinois Paternity-Petition to Establish Father-Child Relationship is a legal petition filed by a father to establish paternity of a child in the state of Illinois. This process is used by fathers wanting to officially be recognized and legally declared as a child’s father. This petition is also used to obtain legal rights and responsibilities of being a parent, such as the right to be consulted in the child’s upbringing, the right to make decisions for the child, and the responsibility to provide financial support. There are two types of Illinois Paternity-Petition to Establish Father-Child Relationship: voluntary and involuntary. In a voluntary paternity petition, both the mother and the father sign an acknowledgment of paternity, which can be done in the hospital when the child is born or at any time before the child reaches the age of majority. In an involuntary petition, the father is served with a petition to establish paternity and must respond within 30 days or a default judgment can be entered against him. If the father does not agree to the petition, then a trial will be held to determine paternity.