The court may modify a child support award subsequent to the one child support percentage for fathers filing of a motion for modification and upon a showing of a material change of circumstance. Be sure the child support and court case numbers are on the requests and keep a copy that has the date on it, as proof of sending them. The parent will not be able to go back and change past amounts of child support owed once those payments are lat If you have any questions about the child support g...