Learn more below! Lap Children: From 7 days old until his/her second birthday (age 7 days to 23 months), a child is considered a lap child and does not need a paid seat; however, Guests may opt to buy a seat for the infant if they prefer.

On Spirit Airlines, children who have not yet reached their second birthday (under 24 months old) are eligible to fly for free as "lap children." This means they do not require a separate paid seat and can travel on the lap of an adult who is at least 15 years old. This policy applies from the time the infant is at least 7 days old until the day before their second birthday. If a child turns two years old during a trip (for example, between the departure and return flights), a seat must be purchased for the return portion of the journey at the standard adult fare. While the "seat" is free for lap infants, some taxes and fees may still apply, especially on international routes. Spirit also allows guests traveling with an infant to bring one diaper bag per child free of charge, which does not count toward the standard "one personal item" limit. Parents must be prepared to provide proof of age, such as a birth certificate or passport, as Spirit gate agents frequently verify the age of toddlers to ensure they are still under the two-year-old limit for free travel.