Flying With a Baby in 2026: Lap Infant Fares, Rules and Car Seats

Updated August 2026

Flying with a baby creates an odd combination of airline rules.

A child under two may be able to fly across the country on your lap without buying another seat. Put the same family on an international flight and the infant may need a ticket, taxes, fees or a percentage of the adult fare even though the baby still does not get a seat.

Then there are car seats, bassinets, strollers, passports, birth certificates and the surprisingly important question of whether your child turns two before the trip home.

The short version: Children under two can generally travel as lap infants on major U.S. airlines. Domestic lap-infant travel usually does not require buying the child a separate seat. International pricing varies substantially by airline and itinerary. Once the child reaches age two, a separate ticket and seat are required.

There is also a safety issue worth understanding before deciding whether to use the free lap-infant option. The FAA strongly recommends that young children travel in their own purchased seat using an approved child restraint system rather than on an adult’s lap.

Question	Quick Answer
Can a child under 2 fly on my lap?	Generally yes on U.S. airlines
Is a lap infant free domestically?	Generally no separate seat fare; airline rules still apply
Is an international lap infant always 10% of the adult fare?	No
Does a lap infant need to be on the reservation?	Yes
Does a 2-year-old need a seat?	Yes
Does TSA require ID for a child under 18 on a domestic flight?	No, but the airline may require proof of age
Does a baby need a passport internationally?	Generally yes
Can I use a car seat on the plane?	Yes, if it is approved for aircraft use and the child has a seat
Is a lap infant as safe as a child in a car seat?	The FAA recommends an approved restraint in the child’s own seat

Is a Baby Under 2 Free on a Domestic Flight?

On the major U.S. airlines, a child who has not reached their second birthday can generally travel on an accompanying adult’s lap without purchasing a separate seat for a domestic flight.

You may see several names for this:

• Lap infant
• Lap child
• Infant in arms
• Infant-in-arms

They mean essentially the same thing: the child is included in the reservation but does not occupy a separate passenger seat.

Do not simply show up at the airport with the baby. Airlines generally require the lap infant to be added to the reservation even though you are not purchasing another domestic seat.

The exact process varies. Some airlines let you add the infant during online booking. Others let you modify an existing reservation or require additional handling for certain international itineraries.

Lap Infant Fares on Major U.S. Airlines

The domestic rules look fairly similar. International pricing does not.

Airline	Domestic Lap Infant	International Lap Infant
Delta	Free within the U.S.	Generally 10% of applicable adult fare plus international taxes and fees
American	Infant under 2 may travel on an adult’s lap; add infant to reservation	Taxes and a percentage of the adult fare may apply
United	Children under 2 may travel on a parent’s lap	Charges and ticketing depend on the international itinerary
Southwest	No separate ticket charge for qualifying lap child	Applicable government taxes and fees apply
JetBlue	No cost to add a qualifying lap infant	Variable infant fee applies on certain travel from an international destination to the U.S.
Alaska	One lap infant per ticketed adult on domestic travel	10% of applicable adult fare plus taxes on long-haul international flights

These policies change, and partner-operated flights can follow different rules. Check your airline’s current infant policy before buying the ticket.

• Delta infant travel policy
• American Airlines traveling with children
• United traveling with children
• Southwest traveling with an infant
• JetBlue lap infant policy
• Alaska lap infant policy

International Infant Fares Are More Complicated Than “10%”

You will frequently hear that an international lap infant costs 10% of the adult fare.

Sometimes that is exactly what happens. It is not a universal rule.

Delta currently says an international infant in arms generally pays 10% of the adult fare plus international taxes and fees.

Alaska similarly charges 10% of the applicable adult fare plus taxes for lap infants on long-haul international travel.

American tells passengers that taxes and a percentage of the adult fare may apply on international trips rather than presenting one universal price on its consumer travel page.

JetBlue uses a different approach. It says there is no cost to add a lap infant to the reservation, but an infant fee is assessed when a lap infant departs from an international destination for the United States, with exceptions for Puerto Rico and the U.S. Virgin Islands. The amount depends on the international origin.

Southwest says international lap children can incur government-imposed taxes and fees.

The practical lesson is simple: price the infant as part of the actual itinerary before deciding what a trip costs.

Do not calculate 10% of the fare you see on Google Flights and assume that will be the baby’s final price.

Why Can an Infant Fare Be More Expensive Than Expected?

Airfares contain several pieces.

A discounted infant fare may apply to the airline’s fare while taxes, airport charges and government fees are calculated separately. Some of those charges do not shrink merely because the passenger is eight months old.

There is another wrinkle: the “adult fare” used to calculate an infant fare may not always work out exactly the way a traveler expects from looking at the lowest advertised ticket price.

That is why the useful number is the actual infant price quoted for your reservation.

If you are comparing airlines for an international family trip, add the infant before making your final fare comparison.

Do You Have to Add a Lap Infant to the Reservation?

Yes.

A free domestic lap infant is still a passenger.

The airline needs to know that the child is traveling for passenger records, safety planning and equipment requirements. Aircraft rows have limits on lap infants because only certain numbers of supplemental oxygen masks are available.

Delta, American, JetBlue, Alaska and Southwest all provide procedures for adding a lap infant to a reservation.

If two adults are traveling with two lap infants, do not assume everyone can sit together in the same set of seats. Oxygen-mask restrictions can affect where the airline is allowed to seat you.

What Happens If Your Baby Turns 2 During the Trip?

This is an easy problem to overlook when buying a round trip months in advance.

Once the child reaches their second birthday, the lap-infant exception ends.

Delta specifically says a ticket must be purchased if the child turns two during the trip. American says that if the infant turns two during the trip, the child needs their own seat for the remainder of the journey. JetBlue similarly says a seat will be required for a return flight after the child’s second birthday.

Suppose your child is 23 months and 29 days old on the outbound flight but turns two during the vacation.

The outbound might qualify for lap-infant travel. The return does not.

Price this before buying the itinerary. JetBlue even suggests purchasing two one-way tickets in this situation so that the return can be booked correctly.

Does a Baby Need ID to Fly?

There are two separate questions here: what TSA requires and what the airline requires.

TSA says children under 18 generally do not need to present identification for domestic U.S. air travel.

But an airline may want proof that the child really is under two and therefore qualifies as a lap infant.

Airline requirements differ.

For example:

• Southwest says it may request proof of age and accepts specified government-issued documents such as a passport or birth certificate.
• JetBlue requires proof of age for lap infants and lists passports, birth certificates and immunization records among its acceptable documents.
• Alaska reserves the right to request proof of age such as a birth certificate or passport.
• American says passengers may have to present proof of age such as a birth certificate.

Check the airline before traveling. In particular, do not assume that a photo of a document stored on your phone will satisfy the airline. Southwest, for example, specifically says electronic screenshots or photos do not qualify as its required proof of age.

Does a Baby Need a Passport for an International Flight?

Plan on your baby needing their own passport for international travel.

A parent’s passport does not cover the infant.

JetBlue explicitly requires a valid passport for lap infants traveling internationally, and other airlines direct parents to comply with the documentation requirements of the countries involved.

Depending on the destination and who is traveling with the child, additional documentation may be required. A consent letter can be relevant when a child travels internationally with only one parent or with another adult.

Check the entry and exit rules for the actual countries on the itinerary rather than relying solely on the airline.

Should You Buy a Separate Seat for a Baby?

For many families, this is where cost and safety collide.

Airlines permit qualifying children under two to fly on an adult’s lap. The FAA recommends something safer.

The FAA says:

The safest place for a child under two on a U.S. airplane is in an approved child restraint system or device, rather than on an adult’s lap.

The concern is turbulence and sudden movement. An adult may be wearing a seat belt while the infant is essentially unrestrained.

The FAA therefore strongly encourages parents to buy the child a seat and use an approved restraint for the entire flight.

You can read the FAA’s current guidance at Flying with children.

Why Is a Lap Infant Allowed If a Car Seat Is Safer?

Because the U.S. rules permit children who have not reached their second birthday to travel on an adult’s lap.

Permitted and recommended are two different standards.

The airline can therefore legally offer you the lap-infant option while the FAA can simultaneously recommend buying a seat and using an approved restraint.

For parents, the decision often comes down to a substantial expense. Buying another ticket can add hundreds or even thousands of dollars to a family trip.

It is still useful to understand what you are choosing rather than assuming that lap travel and restrained travel provide the same protection.

Can You Bring a Car Seat on an Airplane?

Yes, but the car seat must be approved for use aboard an aircraft.

For a U.S.-manufactured car seat, look for labeling stating that the restraint is certified for use in motor vehicles and aircraft.

If you purchased a seat for your child and have a properly approved restraint that is appropriate for the child, FAA rules generally protect your ability to use it. The airline can impose reasonable rules about where the restraint is installed.

A window position is commonly preferred because the car seat cannot block another passenger’s access to the aisle.

Car seats cannot be installed in exit rows.

Follow the child-seat manufacturer’s instructions regarding whether the seat should be rear-facing or forward-facing for your child’s size.

What If the Car Seat Doesn’t Fit the Airplane Seat?

Aircraft seats vary in width and configuration.

The FAA says that if you bought the child a ticket and an approved child restraint does not fit in a particular aircraft seat, the airline is responsible for accommodating the restraint in another seat in the same class of service.

That does not mean every car seat can be installed anywhere you choose.

Airlines can restrict restraints from places such as exit rows, certain premium seats or positions where the restraint would block another passenger’s escape path.

Check both your car-seat dimensions and the airline’s rules before travel, especially if you are using a very wide seat.

What Is a CARES Harness?

CARES stands for Child Aviation Restraint System.

It is a lightweight FAA-approved harness that works with the airplane seat belt and can be much easier to carry through an airport than a full car seat.

But CARES is not a replacement for an infant car seat for every child.

The FAA certifies CARES for children who:

• Weigh between 22 and 44 pounds
• Are up to 40 inches tall
• Can sit upright independently in a forward-facing position
• Have their own aircraft seat

That means many young infants are too small for CARES.

It is also an aviation restraint, not a car seat. You cannot use it as your child’s restraint in a rental car after landing.

The FAA also warns that counterfeit CARES-style restraints are sold online. Check for the proper FAA approval marking rather than buying something merely because the listing says “airplane harness.”

Do You Need to Buy a Seat to Use a Car Seat or CARES?

Yes.

A restraint system requires an aircraft seat in which to install it.

Buying a ticket is the only way to guarantee that your child will have that seat.

Some airlines may allow a lap infant to use an otherwise empty seat if one remains available, but you should never build your travel plan around that possibility.

A full flight eliminates the empty seat immediately.

Can You Use a Baby Carrier During Takeoff and Landing?

Do not assume that a wearable baby carrier counts as an approved aircraft restraint.

The FAA says baby carriers, booster seats and backless child restraints cannot be used as the required child restraint during ground movement, takeoff or landing.

Airlines can have their own rules about whether a carrier may be used during the cruise portion of the flight.

A sling strapped to a parent and an FAA-approved CRS are not interchangeable from an aviation-safety perspective.

What About Airplane Bassinets?

Bassinets can be extremely useful on long flights, but there is no single U.S. airline bassinet rule.

Availability depends on airline, aircraft and seat.

For example, Delta’s SkyCots are available only on qualifying widebody flights, have size and weight restrictions, and are limited in number. American offers bassinets on certain Boeing 777 and 787 aircraft on a first-come, first-served basis and limits them to smaller infants.

A bassinet generally does not solve the safety issue during turbulence. Airlines require babies to be removed from bassinets and held or otherwise secured when conditions require it.

If a bassinet is important to your trip:

1. Check the exact aircraft.
2. Read the airline’s weight and size limits.
3. Request it as early as the airline allows.
4. Understand that a request may not be a guarantee.
5. Have a plan for the flight if the aircraft changes or the bassinet is unavailable.

Do Strollers and Car Seats Count as Checked Bags?

Often they do not, but baggage treatment is airline-specific.

Several major airlines are generous with basic child equipment.

American allows a stroller and car seat to be checked free when traveling with a child, subject to its handling rules. Delta says strollers and child safety seats are not counted as standard baggage and can be checked free. JetBlue allows a stroller and car seat with a lap infant and says checking a child safety seat does not count toward the normal checked-bag allowance.

Other baby equipment may be treated differently.

A playpen, portable crib or wagon can be considered a normal checked bag even when a stroller or car seat would be free.

Check the actual airline policy before arriving at the airport with half the nursery.

Should You Gate Check the Stroller?

For many families, yes.

Keeping the stroller until the gate can be extremely useful for getting a baby, diaper bag and assorted family debris across a large airport.

But there are tradeoffs.

Gate-checked equipment still goes into the airline’s baggage-handling system. If you have an expensive stroller that you would hate to see scratched or damaged, consider whether a simpler travel stroller makes more sense.

Large or non-collapsible strollers can also have different check-in requirements. American, for example, requires certain larger stroller types to be checked at the ticket counter rather than the gate.

Can You Bring Formula and Breast Milk Through TSA?

Yes.

TSA permits formula, breast milk, toddler drinks and baby food in quantities greater than the normal 3.4-ounce liquid limit when traveling through U.S. airport security.

Cooling accessories such as ice packs can also be permitted for these items.

Tell the TSA officer that you are carrying infant feeding items and separate them from the rest of your belongings when requested for screening.

TSA’s current family-travel guidance is available at Traveling with Children.

What Is the Best Airplane Seat When Flying With a Baby?

There is no single answer because the right seat changes depending on how the child is traveling.

If you’re using a car seat

A window seat is usually the easiest choice and is preferred by several airlines because the child restraint is less likely to block another passenger from reaching the aisle.

Avoid exit rows and check restrictions for premium cabins or unusual seat designs.

If you’re requesting a bassinet

You will usually be dealing with specific bulkhead positions on an equipped aircraft. Choose based on the airline’s bassinet map rather than simply selecting any bulkhead seat.

If you’re traveling with a lap infant

Remember the oxygen-mask issue. Airlines may limit the number of lap children permitted in a row or section of seats.

If two adults are traveling with two lap infants, the airline may be unable to seat both adults exactly where you expected.

When I Would Seriously Consider Buying the Baby a Seat

The extra ticket can be expensive, so there is no point pretending this is an insignificant decision for a family.

I would give a separate seat serious consideration when:

• The flight is long
• The itinerary is overnight
• You already have an aircraft-approved car seat
• The child sleeps well in the car seat
• You expect substantial turbulence
• You have multiple flight segments
• You would simply be more comfortable knowing the child is restrained

A separate seat also gives the family physical space. Holding a 20-pound child for five or eight hours can become exhausting long before the flight ends.

When the Lap-Infant Option Can Save a Lot of Money

The opposite side of the equation is obvious.

If a domestic ticket costs $600, taking a qualifying child as a lap infant can save roughly the price of another $600 seat.

For a family that flies several times during the child’s first two years, that can add up quickly.

On an international trip, compare the actual lap-infant charge with the price of buying another seat. If the infant fare plus taxes is already substantial, the price difference between lap travel and a separate ticket may be smaller than you expected.

Run both prices before deciding.

What I Would Check Before Booking

Before paying for a flight with a baby, I would answer these questions:

1. How old will the child be on every flight?
2. What does this airline charge for a lap infant on this exact itinerary?
3. Does the baby need a separate international ticket?
4. What proof of age will the airline accept?
5. Do we want to purchase a separate seat?
6. Is our car seat certified for aircraft use?
7. Will that car seat fit the airline seat?
8. Does the aircraft offer bassinets?
9. What can we check free?
10. Do we have the baby’s passport and any additional international documents?

Answering those before booking is much easier than discovering the problem at an airport ticket counter with a baby and six bags.

A Note About Family Travel Gear

Traveling with a baby makes the useful-versus-useless travel-gear distinction especially important.

You already have more things to carry. Anything added to the bag should solve a real problem.

For our broader approach to chargers, trackers, power banks and other equipment that actually earns its place in a carry-on, see Useful Travel Gear for Flying: The Stuff That Actually Helps.

Frequently Asked Questions

Can a baby under 2 fly for free?

On major U.S. airlines, children under two can generally travel as lap infants on domestic flights without purchasing a separate seat. The infant still needs to be added to the reservation and the airline may require proof of age.

How much does a lap infant cost internationally?

It depends on the airline and itinerary. Some airlines charge around 10% of the applicable adult fare plus taxes, while others charge different infant fees or government taxes. Do not assume 10% applies to every airline.

Does Delta charge for a lap infant?

Delta says an infant under two can travel on an adult’s lap free within the United States. International lap infants generally cost 10% of the applicable adult fare plus international taxes and fees.

Does American Airlines charge for a lap infant?

American permits one infant under two to travel on the lap of a ticketed accompanying adult. For international travel, American says taxes and a percentage of the adult fare may apply.

Does United allow lap infants?

Yes. United permits children under two to sit on a parent’s lap. International ticketing and charges can vary by itinerary, so price the infant when making the reservation.

Does Southwest charge for lap infants?

A qualifying lap child can travel domestically without a separate ticket charge. Government taxes and fees can apply to international travel. The child must still be added to the reservation.

Does JetBlue charge for a lap infant?

JetBlue says there is no cost to add a qualifying lap infant to the reservation. For certain international travel back to the United States, however, JetBlue charges an infant fee that varies by point of origin.

Does Alaska Airlines charge for a lap infant?

Alaska permits one lap infant per ticketed adult for domestic travel. On long-haul international flights, Alaska says lap infants travel for 10% of the applicable adult fare plus taxes.

Does a lap infant need a boarding pass?

The child must be included in the airline’s reservation and passenger records. The exact document or boarding-pass process varies by airline and itinerary.

Do babies need ID for domestic flights?

TSA does not generally require identification from children under 18 for domestic U.S. flights. Airlines can separately require proof of age for a child traveling as a lap infant.

Can I use a birth certificate for a lap infant?

Many airlines accept birth certificates as proof of age, but their rules about originals, copies and alternative documents differ. Check your airline’s current requirements before leaving home.

What happens if my child turns 2 during vacation?

The child will need a ticket and their own seat for flights taken after the second birthday. Do not assume a round-trip lap-infant reservation remains valid merely because the child was under two on the outbound flight.

Is it safer to buy a baby a seat?

The FAA strongly recommends placing a child under two in an approved child restraint system in the child’s own seat rather than traveling with the child on an adult’s lap.

Can I bring my baby’s car seat on the plane?

Yes, if the restraint is approved for aircraft use and you have a seat in which to install it. Look for the required aircraft-use certification on the restraint.

Can a car seat go in an aisle seat?

Airline placement rules vary, but window seats are commonly preferred so a child restraint does not block another passenger’s path to the aisle. Car seats cannot be used in exit rows.

What is a CARES harness?

CARES is an FAA-approved aircraft restraint for children who can sit upright independently and meet its size requirements. The FAA lists it for children weighing 22 to 44 pounds and up to 40 inches tall.

Can an infant use a CARES harness?

Only if the child meets the device’s weight, height and developmental requirements. Many babies are too small. CARES does not replace a rear-facing infant car seat.

Can I bring breast milk or formula through airport security?

Yes. TSA permits breast milk, formula, toddler drinks and baby food in quantities greater than the normal 3.4-ounce liquid limit, subject to screening procedures.

Do airlines check strollers and car seats for free?

Many major U.S. airlines do, including specific allowances at American, Delta and JetBlue, but rules for strollers, wagons, portable cribs and other child equipment vary. Check the airline you are actually flying.

Can I request a bassinet on an international flight?

On some airlines and aircraft. Bassinets are limited, have weight or size restrictions and are generally tied to particular seats. Request one early and do not assume availability is guaranteed.