A Putative Father is the alleged father of a child, either identified by the birthmother or unknown, who has not legally established his paternity of the child. A Putative father is not a legal father. A Putative Father must take legal steps to establish his paternity in order have any right to receive further notice of an Adoption proceeding or to have standing to contest an adoption. In Illinois, a Putative Father must register with the Birth Father Registry in order to receive notice of a pending adoption wherein he has been named as a Putative Father.

A biological father, or alleged biological father becomes a party whose consent to adoption is required if he has been informed that he is the father of the child, and:

1. marries the mother,
2. lives with the mother and supports the child,
3. establishes himself as the legal father by filling a parentage proceeding, or
4. Registers with the Illinois Putative Father Registry AND initiates a parentage proceeding.

A Putative Father may consent to the adoption of an unborn child by signing a Denial of Paternity and Consent to Adoption. Such a consent is irrevocable once signed and his parental rights may be terminated thorough court order prior to the birth of the child. A Putative Father may also consent to the adoption of an unborn child by signing a Declaration of Paternity and Consent to Adoption. Such a consent may be revoked at any time prior to the child's birth, but becomes irrevocable once the child is 72 hours old.

A legal father may consent to the adoption by signing a Declaration of Paternity and Consent to Adoption or by surrendering his rights to a licensed child welfare agency.

Depending on the circumstances, it may be wise to also make "Unknown Father" and "All whom it may concern" parties to the adoption proceeding. Following publication of legal notices in accordance with statute, the parental rights of all unknown fathers can be terminated.