Your first flight with a baby feels easier once you know what the airline, security, and the plane will ask of you. This guide covers the five things parents ask about most, plus what to do at home before you leave.
Rules differ by airline and change over time, so check TSA.gov and your airline's page before you fly. We reviewed the sources below on October 10, 2026.
What documents does a baby need to fly?
For a flight inside the U.S., airlines can ask you to prove your baby is under 2 if they'll sit on your lap. American, for example, says you may be asked for proof of age such as a birth certificate. Southwest requires an original or a paper copy of a birth certificate or passport for a lap infant and doesn't accept screenshots or phone photos. Each airline sets its own rules, so bring a paper copy and check yours. Look up your airline's lap child policy and save a screenshot of it.
For international flights, your baby needs their own passport, even on your lap. For domestic flights, United and Southwest both say children under 18 don't need an ID at security.
Some airlines require a doctor's letter for very young newborns. Delta and American both require one for babies under 7 days old, and Southwest accepts lap infants only from 2 weeks old. If your baby is a newborn, ask your airline when you book.
Before you leave home, print a copy of your baby's proof of age and keep it in your carry-on. Save a photo on your phone as a backup.
On Southwest, a lap infant doesn't get a boarding pass. You get a Boarding Verification Document at the airport kiosk or counter instead.
Can you bring formula and breast milk through security?
Yes. TSA allows formula, breast milk, toddler drinks, and baby food in amounts over 3.4 ounces, and they don't need to fit in a quart-sized bag. To make screening go faster:
- Tell the officer at the start that you're carrying baby liquids over 3.4 ounces.
- Take them out of your carry-on so they can be screened separately.
- Use clear bottles when you can. Pouches and bags can take longer.
- Pack ice packs or gel packs if you need to keep milk cool. TSA allows them.
You can ask the officer not to X-ray or open the items. TSA says that leads to extra screening for you, so give yourself more time. Bring enough for the trip plus extra in case of delays. If you have questions about screening, you can call TSA Cares at (855) 787-2227 up to 72 hours before your flight.
How do strollers, car seats, and carriers work at security?
TSA screens strollers, car seats, and baby carriers by X-ray. Collapse them so they fit on the belt. Items that don't fit get a hand inspection.
You'll take your baby out of the stroller or car seat and carry them through the metal detector. A baby can stay in a sling or carrier, but you may get extra screening. Children 12 and under can keep their shoes and headwear on.
Should your baby fly on your lap or in their own seat?
Children under 2 are allowed to fly on a lap. The FAA strongly discourages it and recommends a car seat in a ticketed seat for the whole flight. The FAA also says that buying a ticket is the only way to guarantee you can use a car seat, and it points to turbulence as the top cause of pediatric injuries on planes.
If you bring a car seat:
- Look for the label that says it's certified for use in motor vehicles and aircraft.
- Check that it's no wider than 16 inches. If it's wider, the airline may ask you to check it.
- Don't install it in an exit row.
The FAA-approved CARES harness is for children who weigh 22 to 44 pounds and can sit upright on their own, so it doesn't fit a young baby.
Both choices are allowed. Ask your pediatrician and your airline which one fits your trip.
Two more rules to check. Delta and American both allow only one lap infant per adult, so a second child under 2 needs their own seat. American also says your child must be under 2 for the whole trip, so if your child turns 2 before the return flight, they need their own seat for it.
Some flights offer a bassinet, but they're limited. American offers them on certain widebody aircraft, first come, first served at the gate. Delta offers them on certain longer flights and limits them to two per aircraft. United offers a free bassinet only in Polaris business class or on select international Economy flights, and supply is limited. Ask before you count on one.
What should you keep within reach on the plane?
Pack one small bag you can reach during the flight, not one that goes in the overhead bin. Put in:
- Diapers and wipes
- A full change of clothes for your baby
- A spare top for you
- Formula or bottles, and a pacifier if your baby uses one
- A blanket
- A plastic bag for dirty clothes
Pack more than you think you need. Delays happen.
United suggests keeping snacks on hand to ease ear pressure during takeoff and landing, and many parents offer a bottle, nursing, or a pacifier to babies. If you have questions about your baby's ears or health before you fly, ask your pediatrician.
First flight checklist
- ☐ Look up your airline's lap child or infant policy and save a screenshot
- ☐ Print a copy of your baby's proof of age for your carry-on, and save a photo on your phone as a backup
- ☐ Bring a passport for your baby if you're flying internationally
- ☐ Download your boarding passes before you leave home
- ☐ Decide lap or own seat, and check your car seat's aircraft label if you bring one
- ☐ Ask your airline if a bassinet or bulkhead seat is available
- ☐ Pack formula or bottles in clear containers and tell the officer at security
- ☐ Pack a full change of clothes for your baby and one for you in the bag you keep with you
Keep all of this on your phone with FamGo
FamGo keeps your documents, boarding passes, packing list, and prep tasks in one place, built around your baby's age. Your trip data is stored on your device, so you can open it when the airport signal is weak. The free plan includes up to three documents per trip.
Open FamGo, add your baby's age, and it builds your packing list and prep tasks for you.
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