This situation doesn’t happen often, but it’s a fun one to talk about. An unmarried woman and man have a child together, we’ll call them Jack and Jill. When the child is born, we’ll call it Alex, Jill promises Jack that he is the father.

She promises that she didn’t have any other sexual partners for months leading up to the pregnancy. Jack believes Jill and decides to forgo a paternity test (mistake numero uno), and signs the birth certificate as Alex’s father.

A few years later, Jack discovers he is in fact not the father, and now wants to take away his last name from Alex. This is the tricky part.

Only a parent can change a child’s last name, which means that if Jack uses a paternity test to prove he isn’t the father, he forfeits the ability to change the name.

With a definitive paternity test and a bit of legal maneuvering, Jack will most likely be able to get his name removed off Alex’s birth certificate, but the name will remain.

Jack’s best bet is to use a paternity test to prove he has no legal responsibility to the child, and then negotiate with the mother to get the name changed. If Jill refuses to change Alex’s last name, Jack might be out of luck.

The lesson to be learned here is to always get a paternity test, unless you’re extremely confident.

In Oklahoma, when a married couple has a baby the husband and wife are assumed to be the mother and father. When an unmarried couple has a baby there is no assumption of parenthood.

Unmarried couples have two options, sign an acknowledgement of paternity (AOP), which means they both agree they are the parents, or take paternity test.
When an AOP is signed it’s pretty straightforward, but if tests are involved a lawyer should also be involved.