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. The intention of this letter is to provide consent for a minor child to travel without the company of both legal parents.Use our Child Travel Consent form to prove that a child can travel without their parents or guardians. Know what documents a child needs to travel to or from the U.S. All children, including infants, must have their own travel documents. We are all British citizens with British passports. How do I write a consent letter for my child to travel? Children under 18 may need a Letter of Consent to travel internationally without both parents. Country-specific regulations. The easiest thing to do would be to have each parent write a separate letter, sign it in front of a notary, and give them to you for travel. A travel consent is used to when traveling with minor children whether on trips with organizations, family members, or one parent.