Yes, cruise lines are extremely meticulous about checking a child's age, and they do so primarily during the initial booking and embarkation process. You are required to provide the child's official birth certificate or passport, which is scanned into the ship's manifest. In 2026, this is not just for pricing accuracy, but for safety and regulatory compliance. Cruise lines have strict minimum age requirements (usually 6 months for standard sailings and 12 months for trans-oceanic ones) and use age to determine which youth clubs, shore excursions, and pool areas a child can access. If a child's age is found to be misrepresented, the cruise line reserves the right to deny boarding without a refund or to move the child to the correct age-based programming. It is a peer-to-peer warning: do not try to "age up" a child to get them into a teen club or "age down" to save money; the digital manifests are checked multiple times before the ship even leaves the pier.