MARIETTA - It's a common mistake couples make when they have a child out of wedlock.

Cobb Juvenile Court Judge Gregory Poole said he sees "boatloads" of unmarried couples in his courtroom who think the father is legitimate because he is on the child's birth certificate. But according to Georgia law, he's not.

In Georgia, a child born to an unmarried couple only has one legitimate parent - the mother. That means if the mother passes away, the child's father is not considered a legal guardian. Minor paperwork can make the father legitimate, but many don't know they need to fill anything out.

If the father is illegitimate, he's called a putative father in the courtroom.

"We deal with it on a daily basis when parents are brought in accused of depriving a child," Poole said. "If a child is deemed deprived by a court, the judge can place the child with any number of people. I've placed a child with a putative father before, but in those cases we really encourage the father to become legitimate so he has more rights."

Legitimation is a legal step that gives children the right to inherit from their father, gain access to medical history on their father's side and be placed in a paternal relative's home if their mother can no longer care for them. It also gives the father the right to petition a court to grant him child custody or visitation rights.

Beginning in 2005, a new law allowed legitimation to be offered at the same time and on the same document as voluntary paternity acknowledgment. That form can be signed at the hospital when the child is born or later at vital record offices in Atlanta or in the county where the child was born. Both legitimation and paternity acknowledgement require agreement by both parents, according to the Georgia Department of Human Resources Web site.

It's important for the father to become legitimized, especially before custody hearings.

"In a custody-type case, if you want custody or visitation rights, you would need to be made legitimate. Once you are legitimate, you can have a contested custody battle in superior court," Poole said.

Men who want to become legitimate fathers can fill out paperwork at Cobb's Superior Court to start the process.

Kelli Wolk, chief judge for Cobb's Probate Court, said she doesn't see many legitimation cases in her courtroom. The primary purpose of Probate Court is to ensure estates and guardianships are administered in accordance with the law.

"It doesn't really touch directly on our stuff most of the time. The most common thing we do is temporary guardianship. If a father has a legitimate child, then that would affect his standing to object to temporary guardianship, or he could ask to revoke it once it has been implemented," Wolk said.

Poole said there's now what is called "administrative legitimation," in which a father can fill out a piece of paper that acknowledges he is the father and consents to legitimation. The best part-he can fill out the paperwork at the hospital where the child is born.