See what documents a child needs to travel to or from the US alone or with a parent or relative. Non-US citizen children traveling to the US.While it's recommended to have notarised written consent, it's definitely not required and in my experience you're highly unlikely to be asked for it. No, it is not legal for one parent to leave the US with a minor child without the consent of the other parent. A notarized letter of consent is a crucial requirement when traveling with minors without both parents or guardians. We will be sharing some family travel tips about what documentation is needed, such as a travel consent letter, for international travel with a minor. Completing a travel consent form is easy with Notarize. Keep reading to learn about the notarization process and signer requirements for this document.