What Documents Does a Child Need to Fly in the U.S.? A Checklist by Age
TSA does not require ID for kids under 18 on domestic flights, but airlines can ask for proof of age, especially for lap infants. What to bring for each age, airline differences, and PreCheck rules.
The short answer
For a domestic U.S. flight, a child under 18 does not need an ID to get through TSA security. The documents that matter come from the airline: a lap infant under 2 almost always needs proof of age, such as a birth certificate, and a child flying alone needs the airline's unaccompanied minor paperwork. The adult traveling with them needs a valid, REAL ID-compliant ID or another TSA-approved document.
In this explainer
What to bring, by age and situation
| Situation | TSA requirement | Airline paperwork to bring | Source |
|---|---|---|---|
| Under 2, on your lap | None | Proof of age (birth certificate or passport); some airlines want the original or a paper copy | Southwest, Allegiant |
| Under 2, own seat | None | Their boarding pass; an FAA-approved car seat if you use one | FAA |
| Ages 2 to 17, with an adult | None (TSA) | Boarding pass; a birth certificate copy is a good backup if age could be questioned | Allegiant |
| Flying alone (unaccompanied minor) | None for standard screening | Airline form, proof of age, adult's ID at drop-off and pickup | American Airlines |
| Teen flying alone with TSA PreCheck | Acceptable ID needed to use PreCheck | Boarding pass with PreCheck indicator | TSA |
| The adult | Acceptable ID such as a REAL ID, passport or military ID | Boarding pass | TSA ID list |
Lap infants: the one place parents get turned back
Airlines need to confirm a lap child is really under 2, and they do not all accept the same proof. Compare two published policies:
| Southwest | Allegiant | |
|---|---|---|
| Accepted proof | Original or photocopy of a government-issued ID: passport, birth certificate, or government photo ID | Unaltered copy of birth certificate (digital or printed) or government ID such as a passport |
| Phone photo or screenshot | Not accepted | Digital copy accepted |
| Immunization record | Not accepted | Not listed |
| Extra step | Print a Boarding Verification Document at the airport | Proof of age required |
Because policies differ, a printed copy of the birth certificate is the one document that satisfies both. Keep it in the same folder as your boarding passes. Check your own airline's page before you fly; these rules change.
Car seats on the plane
The FAA says the safest place for a child under 2 is in an approved child restraint system, not on a lap, and it strongly urges using one for the entire flight. Buying a seat for your child is the only way to guarantee you can use one. Before you pack it, look for the label that reads "This restraint is certified for use in motor vehicles and aircraft." For children 2 and older, the FAA also accepts a CARES harness, which is certified for aircraft only.
TSA PreCheck with kids
TSA's family rules split by age when a parent has PreCheck:
- 12 and under: can go through the PreCheck lane with you. Their boarding pass does not need the indicator.
- 13 to 17: can use PreCheck only if the indicator appears on their own boarding pass. That happens when they are on the same reservation as you and your pass shows PreCheck. Leave the child's Known Traveler Number blank if they do not have one.
- On a separate reservation without their own number: not eligible for PreCheck screening.
Children flying alone
Unaccompanied minor programs are set by each airline, not by TSA. American Airlines, for example, asks parents to arrive at least two hours early and bring a birth certificate or passport for the child, the adult's REAL ID-compliant license or other acceptable ID, a phone number, and the name, address and phone number of the adult meeting the child. Children traveling alone cannot check in online or at a kiosk there. The adult picking up also needs ID and a gate pass.
Night-before checklist
- Boarding pass for every ticketed child (and the BVD step for a Southwest lap infant)
- Printed copy of birth certificate for any child under 2
- Your REAL ID, passport, or military ID
- Car seat with the aircraft certification label, if using one
- Unaccompanied minor form and pickup adult details, if a child flies alone
- PreCheck: teen on the same reservation as you, KTN field blank if they have none
Questions readers ask
Does a 16- or 17-year-old need ID to fly domestically?
TSA does not require ID for travelers under 18 on domestic flights. Some airlines still ask teens flying alone to prove their age, and a teen flying alone with TSA PreCheck needs an acceptable ID to use PreCheck screening.
Can I show a photo of the birth certificate on my phone?
It depends on the airline. Southwest says screenshots and phone images are not accepted for lap infants, while Allegiant accepts an unaltered digital or printed copy. A paper copy works for both.
Does my baby need a ticket?
Children under 2 can usually fly on a parent's lap. The FAA says buying a seat is the only way to guarantee you can use an approved car seat, and it strongly urges using one for the whole flight.
What ID does the parent need?
Adults 18 and older need an acceptable ID at the checkpoint. Since May 7, 2025, TSA no longer accepts state driver's licenses or IDs that are not REAL ID compliant.
Sources and fact-check
- Do minors need identification to fly within the U.S.?, TSA
- Acceptable Identification at the TSA Checkpoint, TSA
- TSA PreCheck for Families, TSA
- Flying with Children, Federal Aviation Administration
- Southwest Airlines Family Travel Hub, Southwest Airlines Newsroom
- Traveling with Children, Allegiant Air
- Children traveling alone, American Airlines
Rules change. Spot something out of date? Tell us.
