Appear in Person

• Your child must apply in person with both of his parents or guardian. If only one parent can appear, you will need a notarized statement of consent from the other parent, according to us-passport-service-guide.com.
  
  

Application Form

• You will need to fill out an application for your child's U.S. Passport. The form must be signed in front of an authorized agent, according to travel.state.gov.
  
  

Documentation

• You will need an original copy of the child's birth certificate, a photo ID of the child and two passport sized photos, according to us-passport-service-guide.com. The person applying for the passport on the child's behalf must establish his relationship to the child, if it is not certified by the child's birth certificate.