Is the natural father's consent to the adoption necessary?
If the paternity of a natural father has been officially established, and he has not given up the rights to his child through abandonment, willful termination of parental rights, or other means, then his consent would be necessary in order for a child to be adopted. In fact, the consent of both natural parents is required in an adoption, unless one of the aforementioned terms is met.
Consent Requirements for Adoption
A parent may give up his (or her) right to consent in a number of ways. If a father, for example, has denied parentage of a child, has failed to support the child, has gone missing and cannot be contacted (typically for a period of a year or more and/or after reasonable attempts to contact him), or if his paternity is in question and not established by scientific testing, his consent may not be required. Theoretically, in such a situation the natural mother could put a child up for adoption without seeking the natural father's consent to do so.
In all states, however, both parents (provided paternity of the father is properly established) have primary rights to consent, meaning both of them must agree to a motion such as adoption before it can take place. This includes a situation where a mother with custody of the child may remarry and her new husband wishes to adopt the child as his own. The natural father's consent would be required in this case, unless any of the above circumstances applied.
There are a number of legal requirements that must be met in order for an adoption to become final. There are also different waiting periods that exist based on where you live, and a wide variety of documents that must be completed. In order to make sure the process goes as smoothly as possible and that the adoption is legal, it is imperative you hire a lawyer to guide you through the process.