Flying with kids is complicated.
One of the biggest concerns when flying with kids is seating on the plane. Do parents need to spend the extra money to purchase tickets with advanced reserve seating? Will an airline really separate young children from their parents if they don’t buy reserved seats? Are parents stuck asking other passengers if they will switch seats? I can’t imagine any random adults really want to entertain my child for the entire flight. Here are the details for different airlines according to their customer service representatives. And while we are sharing the official information from each airline as of today, it’s impossible to predict how airline personnel will choose to seat families.
Allegiant Air
Allegiant Air says they will do their best to accommodate families, but the availability of seats together cannot be guaranteed. They recommend purchasing reserved seats when you book your travel or during online check-in.
American Airlines
American Airlines aims to keep families with children under the age of 15 together. They recommend booking everyone on the same reservation so their computer system will detect that you are a family traveling together. If you chose a Basic Economy fare or don’t want to choose seats ahead of time, the system will search for seats together automatically before the day of departure. If seats are limited, American Airlines will ensure that each child under the age of 15 is seated next to at least 1 adult in your group.
Delta Air Lines
If you buy Basic Economy tickets, seats are not assigned until after check-in. Delta customer service says they will assist with seating a parent with children ages five and under. If the child is over five, Delta will give parents the opportunity to purchase an advance seat assignment prior to check-in.
Frontier Airlines
Purchasing a seat assignment is the only way to guarantee that your family will be seated together. That said, Frontier does try to auto-assign seats to keep groups together at check-in. If your party is separated, the customer service representative recommends approaching the gate agent prior to departure. They are often able to accommodate seating requests.
JetBlue
JetBlue does not charge for seat assignments if you book through their website. You can opt to purchase an Even More Space seat if you want extra room. If needed, you can change your seat assignments when you check-in for your flight.
Southwest Airlines
Southwest Airlines does not assign seats to any of its passengers. Instead, it boards passengers in groups A, B, and C and they can pick any available seat once they board the plane. Families with children age six or under will board the plane between groups A and B. In theory, that should ensure that there are plenty of open seats for them to sit together. If your group gets split up during boarding, the earlier group can save seats for the rest of the group. The customer service representative recommended grabbing seats near the back of the plane, where there will be more room to save seats.
Spirit Airlines
If you don’t purchase a seat assignment, you will be assigned a random seat at check-in. Spirit can’t guarantee that you will be seated with the rest of your group, including your children unless you purchase your seats in advance.
United Airlines
With Basic Economy tickets, you do not get to choose your seat. Instead, your seat will be automatically assigned to you prior to boarding. According to customer service, families will not be able to sit together with Basic Economy tickets unless they purchase advance seat assignments and adjacent seats are available. There is no age exception.
Flying with kids is a challenge, but knowing the rules about family seating can help you prepare. And the reward of travel and sharing new experiences with your family is worth it! 
