Disney operates on a mostly "honor-based" system for child ages, but in 2026, they have strict policies regarding the age at the start of the trip. A child under 3 is a "special guest of Mickey" and does not require a ticket. If a child turns 3 during the vacation, Disney allows them to remain "free" for the duration of that specific stay—they "do not age" once they have checked in or entered the park on day one. While Cast Members at the turnstiles rarely ask for a birth certificate, they may politely ask a child how old they are if there is a significant discrepancy (e.g., a child who appears to be 5 or 6). If you have booked a "Vacation Package" (hotel + tickets), the age you provide at the time of booking is what the system will use. For activities like Bibbidi Bobbidi Boutique, which has a strict minimum age of 3, you may be asked for verification if the child appears younger, but for general park entry, Disney prioritizes a friction-free guest experience over rigorous ID checks for toddlers.