If children are not travelling with both their parents, (ie: if they are travelling alone, or with another adult), this form can be used to give permission. A notarized letter of consent is a crucial requirement when traveling with minors without both parents or guardians.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. Child's Information: The form includes the child's full name, date of birth, place of birth, and passport or identification details. Apostille Texas can authenticate, legalize, and apostille travel consent letters and apostille travel consent forms for any country in the world. The most common interpretation is that the traveling parent requires a notarized letter something not found in any custody order. This guide includes forms and instructions for a letter and affidavit to request that the court register an out-of-state custody order in Texas.