Washington Petition to Challenge Paternity Acknowledgment and/or Denial of Paternity is a legal document that can be used by a person to challenge a paternity acknowledgment or denial of paternity that was previously signed or filed by another person. It is a way for a person to contest the decision and/or action taken in the past and to ask the court to determine and establish the paternity of a child in question. There are two types of Washington Petition to Challenge Paternity Acknowledgment and/or Denial of Paternity: 1. The Petition to Challenge an Acknowledgment or Denial of Paternity: This petition is used when a person wishes to challenge an acknowledgment of paternity or denial of paternity that was previously signed or filed by another person. 2. The Petition to Establish Paternity: This petition is used when a person wishes to establish the paternity of a child whose paternity is unacknowledged or denied. The petitioner must provide evidence supporting the alleged paternity.