Parents or a legal guardian traveling with children under 18 years must present the child's birth certificate and an identity card with photo (passport, for example) at the check-in. For international travels to Brazil, if just one of the parents is traveling with the child, she/he must present â in addition to the child's certificate of birth and identity card with photo â a letter authorizing the trip signed by the other parent with a notarial certification of signature. In case the parents or the legal guardian, as applicable, cannot or are unwilling to give this authorization, a judicial authorization is required. People who intend to travel to Brazil with children must consult with the Brazilian consulate before traveling for more information.