[Butch Cassidy Slept Here]

First, a lot of airlines only offer a reduced, or free, fare if the child is less than 2 years of age. Whether the discount is for being less than 2, or an older age, the child must be less than the required age on the day of ALL flights, not just on the day the ticket was purchased. To provide another example: If the child's birthday occurred between the outbound and return flights you would owe an adult fare for both the outbound and return.