From August 3, 2026, Thai minors under 18 leaving Thailand via Suvarnabhumi Airport must carry more than a passport. Immigration will accept an original birth certificate, a photocopy or an electronic photo of it. They may also ask for a consent letter from the child's father, mother or both parents, issued or certified by a government agency. Staff and clients who travel with children, including family trips and school or tour groups, should check these documents before departure. The notice does not specify penalties or whether other airports apply the same rule.