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.The form linked below is permission to travel. Download and fill it out. 1. Fill Out Form DS-11 and Print It 2. Get Evidence of US Citizenship (and a photocopy) 3. My question is do you really need the form? Me and my older sister are traveling to Brazil over the summer in June. If the child is traveling with only one of their custodial parents, they must have a letter of consent, preferably in English and notarized. The intention of this letter is to provide consent for a minor child to travel without the company of both legal parents.