Begin using your preferred middle name for your child as early as possible. This establishes a precedent that the name is what you intend. Include it on her pediatrician’s records, day care or school records, and any census or similar forms you complete.
Contact the registrar of vital records in your state. If your child is less than a year old, changing her middle name on her birth certificate usually only requires submitting an application on which you make the request. Find out the procedure in your state, ask for the appropriate form and complete it. Attach copies of your records using the new middle name when you submit the application. You’ll usually receive a new birth certificate within a few months, showing the change.
Download legal name change forms from the Internet if your child is too old, or if the change is significant enough that your state will not change her birth certificate without a court order. Some states offer these forms on their websites. In other states you may have to visit the court to pick them up personally or to receive guidance as to where you can find them. They usually include a petition, an affidavit or certification explaining why you want the change, and a court order or judgment the judge will sign to approve the change.
Complete the necessary forms for a court-ordered name change and file them with the court. If you are married or living with your child’s other parent, you should both sign the petition. This usually eliminates the need for a court appearance. A judge will review your paperwork, sign your order and you'll receive a copy in the mail.
Ask the court clerk for your state's procedure for serving your child's other parent, if you are not married to or living him. Most states require you to give him notice of the change you're requesting so he can object if he doesn't agree. If he does object, the court will generally schedule a hearing before approving the change.
Contact the registrar of vital records in your state again after you've received the signed name change order from the court. Complete the required application to change your child's birth certificate just as you would have done had your state not required a court order. Include a certified copy of the order when you submit the application.