My question involves name change laws in the State of Washington, but the child was born in Missouri.
Long story: I am the biological father of a child who lives in Washington state, but was born in Missouri. I still live in Missouri. The child's mother was married to another man when the baby was born and that man's name was placed on the birth certificate. Two years after the child was born, we found out that I am the biological father of this child. The mother and her husband then divorced. Per the court records, their divorce was a dissolution without children, meaning the husband proved he was not the biological father. Once I learned that I was the biological father, I began paying child support to the custodial parent (the child's mother), but the birth certificate was never updated to reflect my name. Fast forward approximately 8 years and the child is now living in Washington state. Beyond paying support on a monthly basis, I have no contact with the child. The mother has since remarried and her new husband is interested in eventually adopting the child. I recently received a notification from the mother that they are changing the child's last name to the step-father's name and I must sign a document approving the change. The thing is, the birth certificate does NOT have my name on it. There's nothing that states I am the biological father of this child, as the paternity test was a private (not court ordered) test and our child support agreement is a non-binding contract completed outside the courts as well. Should I need to sign anything at all since my name is not legally associated with this child?

