Southwest Airlines infant and child policy: lap infants, strollers and kids flying alone
Your guide to Southwest Airlines infant and child policies. Learn the rules for lap infants, baggage, car seats, strollers, and kids flying alone.
Southwest Airlines has some family friendly policies, including letting lap infants fly free on domestic flights. Each ticketed customer traveling with a child can also check one stroller and one car seat at no cost. However, it’s important to know that a lap infant is not permitted any baggage allowance, checked or carry-on.
| Topic | What Southwest Airlines says |
|---|---|
| Who counts as a lap infant | A child older than 14 days and under 2 years old can be carried as a Lap Child by an adult who is 18 years of age or older. The child does not occupy a seat.Source |
| Lap infant, domestic flights | A lap child can be transported free of charge on domestic flights.Source |
| Baby in its own seat | Buying a seat for your child is the only way to guarantee that a Child Restraint System (CRS) can be used on the plane.Source |
| Lap infant limits | One child older than 14 days and under two years old can travel as a lap child with an adult who is 18 years of age or older.Source |
| Turning 2 during the trip | If a child reaches age 2 and is no longer eligible to be a lap child, a seat must be purchased for them.Source |
| Youngest age to fly | A child must be over 14 days old to travel as a lap child.Source |
| Stroller | When traveling with children, each ticketed customer can check one stroller and one car seat free of charge.Source |
| Checking a car seat | Each ticketed customer traveling with a child is allowed to check one car seat or child restraint system at no cost.Source |
| Car seat on board | Car seats are not allowed in aisle seats and are preferred in window seats. A car seat cannot be placed in a middle seat if it obstructs the exit path for the passenger in the window seat.Source |
| Infant baggage | A lap child is not permitted to have any checked or carry-on baggage.Source |
| Service required for | Children aged five through 11 must travel as Unaccompanied Minors (UMs) if they are not traveling with a passenger who is 12 years of age or older.Source |
| Service fee | Southwest charges an Unaccompanied Minor service fee for each child, which is in addition to the airfare.Source |
| Flights allowed | Unaccompanied Minors can only travel on nonstop flights or on same-plane service, which may have stops but does not require changing planes or flight numbers.Source |
Lap infants and infant fares
On Southwest Airlines, a child older than 14 days and under 2 years old can travel as a lap infant with an adult who is 18 years or older. Lap infants fly free of charge on domestic flights. If a child reaches age 2 and is no longer eligible to be a lap child, a seat must be purchased for them.
An adult can only carry one lap child. To guarantee that you can use a car seat, or Child Restraint System, on the plane, you must purchase a separate seat for your child.
“One child over 14 days and under 2 years of age, not occupying a seat, may be carried as a Lap Child when traveling with an adult (18 years of age or older).”
Official wording, support.southwest.com, checked Oct 21, 2026
“A Lap Child can be carried free of charge domestically.”
Official wording, support.southwest.com, checked Oct 21, 2026
“Purchasing a seat for your child is the only way you will be able to ensure that a CRS can be used onboard.”
Official wording, support.southwest.com, checked Oct 21, 2026
“One child over 14 days and under 2 years of age, not occupying a seat, may be carried as a Lap Child when traveling with an adult (18 years of age or older).”
Official wording, support.southwest.com, checked Oct 21, 2026
“If a child is not eligible to travel as a Lap Child (either because the child has reached age 2 or because the accompanying Passenger is not 18 years of age or older), a seat must be purchased for the child.”
Official wording, support.southwest.com, checked Oct 21, 2026
Newborns and proof of age
Southwest Airlines requires a child to be over 14 days old to travel as a lap infant. The official information we checked does not state whether you need to show proof of age for a lap infant. It is a good practice to carry a copy of your child’s birth certificate or other identification when flying.
For children traveling alone as Unaccompanied Minors, a birth certificate or other valid identification is required at check-in to provide proof of age.
“One child over 14 days and under 2 years of age, not occupying a seat, may be carried as a Lap Child when traveling with an adult (18 years of age or older).”
Official wording, support.southwest.com, checked Oct 21, 2026
Strollers and car seats
For each ticketed customer traveling with a child, Southwest allows one stroller and one car seat to be checked free of charge. If you bring a car seat onboard, the airline prefers it to be in a window seat. A car seat is not allowed in an aisle seat. It also cannot be in a middle seat if it blocks the exit path for the passenger in the window seat.
Remember that purchasing a seat for your child is the only way to ensure you can use a car seat on the plane.
Full details, with the airline’s own wording: Southwest Airlines car seat and stroller policy.
“When traveling with a child(ren), each ticketed Customer may check one stroller and one car seat/child restraint system free of charge.”
Official wording, support.southwest.com, checked Oct 21, 2026
Baby baggage
A key rule to be aware of on Southwest is that a lap child is not permitted to have any checked or carry-on baggage. This means you will need to pack all of your baby’s necessities, from diapers to clothes, within the baggage allowance of the ticketed adult passengers in your group.
Planning your packing strategy around this rule can help make your airport experience smoother.
“A Lap Child may not check or carry on any baggage.”
Official wording, support.southwest.com, checked Oct 21, 2026
Kids flying alone
Children ages five through 11 traveling without a passenger age 12 or older must use the Unaccompanied Minor service. Southwest charges a service fee for each child for this, which is in addition to the airfare. Unaccompanied Minors can only travel on nonstop flights or on same-plane service, which may have stops but does not require changing planes or flight numbers.
At check-in, you will need to provide proof of age for the child, such as a birth certificate. Passengers who are 12 or older can travel by themselves without being classified as Unaccompanied Minors.
Full details, with the airline’s own wording: Southwest Airlines unaccompanied minor policy: ages, fee and rules.
“Children ages five through 11 traveling without an accompanying Passenger age 12 or older must travel as Unaccompanied Minors (UMs) on Southwest Airlines®.”
Official wording, support.southwest.com, checked Oct 21, 2026
Related pages
More on Southwest Airlines:
- Southwest Airlines unaccompanied minor policy: ages, fee and rules
- Southwest Airlines car seat and stroller policy
Same topic, other airlines: