Traveling with an infant can feel overwhelming—especially when it comes to airline rules, documentation, and booking details. If you’re flying with Southwest Airlines and planning to travel with a child under two years old, understanding how to add an infant lap child to a Southwest booking is essential for a smooth and stress-free journey.
This comprehensive guide explains Southwest’s lap infant policy, walks you through step-by-step booking instructions, highlights documentation requirements, and shares expert-backed safety tips supported by reputable organizations such as the CDC, NIH, and Consumer Reports. Whether you’re booking for the first time or modifying an existing reservation, this article provides practical, transparent guidance you can rely on.
What Is a Lap Infant on Southwest Airlines?
A lap infant is a child under the age of two who travels on an adult’s lap instead of occupying a separate seat.Southwest Airlines allows lap infants to fly:
- Free of charge on domestic flights
- With applicable taxes and fees on international flights
This policy is consistent with U.S. Department of Transportation (DOT) regulations, which permit—but do not require—separate seating for infants under two.
Southwest Airlines Lap Infant Policy Overview
Key Policy Highlights
- Infant must be under 2 years old for the entire trip
- One lap infant allowed per adult passenger
- Infant does not receive a seat or boarding position
- Lap infants do not earn Rapid Rewards points
- A boarding verification document is required
Based on publicly available information, there is no confirmed data on Southwest imposing a weight limit for lap infants.
Why You Must Add a Lap Infant to Your Booking
Some parents assume they can simply show up with a baby and be added at the airport. While Southwest does allow airport check-in for lap infants, adding your infant in advance is strongly recommended.
Benefits of Adding a Lap Infant Early
- Faster airport check-in
- Reduced documentation issues
- Ensures compliance with TSA and FAA rules
- Avoids gate delays or rebooking complications
Consumer Reports emphasizes that advance passenger data accuracy reduces travel disruptions—especially for families traveling with minors.
How to Add an Infant Lap Child When Booking a New Southwest Flight
Step-by-Step Instructions (Online Booking)
- Go to Southwest.com
- Enter your origin, destination, and travel dates
- Select the number of adult passengers
- Click “Add Infant”
- Choose “Lap Infant”
- Enter the infant’s:
- Full name
- Date of birth
- Complete booking as usual
Once completed, the infant will be linked to the adult passenger’s reservation.
How to Add a Lap Infant to an Existing Southwest Booking
If you’ve already booked your flight, don’t worry—Southwest makes it relatively easy to add a lap infant later.
Option 1: Add Online via “My Trips”
- Visit Southwest.com
- Click “My Trips”
- Enter your confirmation number
- Select “Add Infant”
- Choose Lap Infant
- Enter infant details
- Save changes
Option 2: Add by Phone
Call Southwest Customer Service and request to add a lap infant. This option is useful if:
- You’re traveling internationally
- Your reservation includes multiple segments
- You encounter website errors
Adding a Lap Infant at the Airport: What to Expect
Southwest allows lap infants to be added at the airport, but this should be your last resort.Airport Process
- Visit the ticket counter (not the kiosk)
- Present infant’s proof of age
- Receive a Boarding Verification Document
Expert insight:
The TSA recommends arriving earlier than usual when traveling with infants due to additional screening and verification steps.
Required Documents for Lap Infants on Southwest
Domestic Flights (U.S.)
- Proof of age may be requested:
- Birth certificate (original or copy)
- Passport (if available)
International Flights
- Infant passport (mandatory)
- Applicable visas (depending on destination)
- Taxes and government fees apply
According to the U.S. Department of State, all international travelers—including infants—must have a valid passport.Lap Infant vs Buying a Seat: What’s Safer?
While lap infants are permitted, the FAA, CDC, and American Academy of Pediatrics recommend purchasing a separate seat and using an FAA-approved child safety seat whenever possible.
Safety Comparison Table
| Option | Cost | Safety Level | Convenience |
|---|---|---|---|
| Lap Infant | Low | Lower | High |
| Separate Seat + Car Seat | Higher | Highest | Moderate |
The NIH notes that turbulence-related injuries disproportionately affect unrestrained passengers, including infants.
Can You Bring a Car Seat If Your Infant Is a Lap Child?
Yes. Southwest allows you to bring:
- One car seat
- One stroller
These items can be:
- Checked for free
- Gate-checked
However, if your infant is flying as a lap child, the car seat cannot be used onboard unless you purchase a separate seat.Boarding Process With a Lap Infant on SouthwestSouthwest offers Family Boarding between boarding groups A and B.
Family Boarding Eligibility
- Traveling with a child 6 years old or younger
- Includes families with lap infants
This allows families to board together and settle in comfortably.How Southwest Handles Seating With Lap InfantsSouthwest’s open seating policy still applies.
Important Seating Rules
- Lap infants cannot occupy exit row seats
- Only one lap infant per row of oxygen masks
- Bulkhead seats may be restricted on some aircraft
Flight attendants may reseat passengers to comply with FAA safety requirements.
International Travel With a Lap Infant on Southwest
Key Differences
- Lap infants are not free
- Taxes and fees vary by country
- Documentation is stricter
Based on publicly available information, there is no confirmed flat international lap infant fee—costs depend on destination and government charges.
Common Mistakes Parents Make (and How to Avoid Them)
- Forgetting proof of age
- Assuming lap infants don’t need to be added
- Waiting until the gate to add the infant
- Not accounting for international taxes
Pro tip: Always review your booking confirmation to ensure the infant is listed.
Expert-Backed Tips for Flying With a Lap Infant
- Feed during takeoff and landing to reduce ear pressure (CDC guidance)
- Use a baby carrier during boarding
- Choose aisle seats for easier movement
- Bring documentation even if not explicitly required
Harvard Business Review research on travel stress highlights preparation as the single biggest factor in improving family travel experiences.Frequently Asked Questions (FAQ)
1. Is a lap infant free on Southwest Airlines?
Yes, on domestic flights. International flights require taxes and fees.
2. Can I add a lap infant after booking?
Yes, online, by phone, or at the airport.
3. Does my infant need a boarding pass?
No, but you will receive a Boarding Verification Document.
4. What if my child turns two during the trip?
You must purchase a seat for the return flight.
5. Are lap infants allowed in exit rows?
No, per FAA regulations.
6. Can I earn points for my lap infant?
No, lap infants do not earn Rapid Rewards points.
7. Do lap infants count toward passenger limits?
Yes, for safety and seating compliance.
8. Can two adults share one lap infant?
No. One infant per adult passenger.
9. Is a birth certificate mandatory?
Not always, but proof of age may be requested.
10. Is it safer to buy a seat for my infant?
Yes. Safety organizations recommend a separate seat with an approved car seat.
Final Thoughts: Is Adding a Lap Infant on Southwest Easy?
Yes—Southwest offers one of the most family-friendly lap infant policies among U.S. airlines, especially for domestic travel. When handled correctly, adding a lap infant is straightforward, affordable, and flexible.
The key is preparation: add your infant early, carry proper documentation, and understand the safety trade-offs. By following the steps and expert guidance in this article, you can focus less on logistics—and more on enjoying your journey with your little one.
