Ticket fares for babies and children On domestic flights, infants under the age of two often fly for free if seated on their parent's lap, and some airlines charge a (discounted) fare. On international flights, airlines often charge 10% of the adult ticket price.

In 2026, the cost to fly with an infant (a child under 2 years old) depends on whether they are a "lap child" or have their own seat. For domestic flights within the U.S., lap infants typically fly for free or for a very small security fee. However, for international flights, airlines generally charge 10% of the adult fare plus full taxes and surcharges for a lap infant. If you prefer the safety of a dedicated seat for your infant, you must purchase a "Child Fare," which usually ranges from 75% to 100% of the adult price. In 2026, some low-cost carriers have moved toward a flat fee for infants—often around $25–$50 per leg. It is important to remember that even if the "fare" is $0, you must still officially add the infant to your reservation to comply with safety regulations and ensure they are listed on the passenger manifest.