Här är länken:
help.cbp.gov/app/answers/detail/a_id/268
Det står bland annat:
Due to the increasing incidents of child abductions in disputed custody cases and as possible victims of child pornography, Customs and Border Protection (CBP) strongly recommends that unless the child is accompanied by both parents, the adult have a note from the child's other parent (or, in the case of a child traveling with grandparents, uncles or aunts, sisters or brothers, or friends, a note signed by both parents) stating "I acknowledge that my wife/husband/etc. is traveling out of the country with my son/daughter. He/She/They has/have my permission to do so."
CBP also suggests that this note be notarized.
While CBP may not ask to see this documentation, if we do ask, and you do not have it, you may be detained until the circumstances of the child traveling without both parents can be fully assessed. If there is no second parent with legal claims to the child (deceased, sole custody, etc.) any other relevant paperwork, such as a court decision, birth certificate naming only one parent, death certificate, etc., would be useful.
Eftersom jag är ensam vårdnadshavare behövde inte pappan skriva på för att de skulle få pass.