Illinois Acknowledgement of Parentage (AOP) is a legal form that establishes the parent-child relationship without the need for a court order. It can be used to establish paternity (fatherhood) or maternity (motherhood). This form is also known as an Acknowledgement of Paternity (AOP) or a Voluntary Acknowledgement of Parentage (VAP). The AOP is a written document that is signed by both the child’s legal parents. It is filed with the Illinois Department of Healthcare and Family Services (HFS). There are two types of Illinois AOP: an electronic AOP and a paper AOP. The electronic AOP is the preferred method and can be completed at any HFS office or online. The paper AOP must be completed and submitted to the HFS in person or by mail. The AOP must be signed and notarized, and both parents must bring valid identification to the HFS office. The AOP is legally binding and establishes the legal relationship between the child and the non-custodial parent. The AOP also establishes the legal rights of both parents, including the right to make decisions regarding the child’s education, healthcare, and other matters. Once the AOP is filed, the non-custodial parent’s name will be added to the child’s birth certificate.