Minors under 18 do not need identification to fly to Puerto Rico. The TSA treats flights between the mainland and Puerto Rico as domestic travel, and its checkpoint policy exempts every passenger under 18 from showing ID.1Transportation Security Administration. Acceptable Identification at the TSA Checkpoint Your child walks through security next to you without a separate document check. The adult flying with them still needs a valid ID, and the airline may want proof of the child’s age for its own reasons, so a little preparation at the counter matters more than anything at the checkpoint.
Why the Domestic Rule Applies
Puerto Rico is an unincorporated U.S. territory, so a flight between the mainland and San Juan follows the same rules as a flight between two states. No passport. No customs form. No immigration check on arrival. Because the trip is domestic, the TSA’s standing exemption for passengers under 18 applies just as it would on a flight from Boston to Denver. Once a traveler turns 18, the exemption ends and they need their own acceptable ID.1Transportation Security Administration. Acceptable Identification at the TSA Checkpoint
One narrow exception exists: an unaccompanied minor enrolled in TSA PreCheck must present an acceptable ID to receive expedited screening.1Transportation Security Administration. Acceptable Identification at the TSA Checkpoint Outside that situation, no ID for the child.
What the Adult Needs to Bring
Every passenger 18 and older must present valid identification at the checkpoint. Since May 7, 2025, state-issued driver’s licenses and ID cards have had to be REAL ID-compliant, marked with the star symbol in the upper corner. Non-compliant licenses are no longer accepted.2Transportation Security Administration. TSA Begins REAL ID Full Enforcement
If your license isn’t REAL ID-compliant, several alternatives work:
- U.S. passport or passport card
- Permanent resident card
- U.S. Department of Defense ID, including dependent IDs
- DHS trusted traveler cards (Global Entry, NEXUS, SENTRI)
- Federally recognized Tribal Nation ID
- Foreign government-issued passport
TSA also accepts certain mobile driver’s licenses from approved states and is testing digital IDs through Apple, Google, and CLEAR.1Transportation Security Administration. Acceptable Identification at the TSA Checkpoint
When the Airline Will Ask About Your Child
The TSA won’t ask your child for papers, but the airline might. Airlines set their own rules for minors, and those rules go beyond what happens at security.1Transportation Security Administration. Acceptable Identification at the TSA Checkpoint Two situations catch families off guard at check-in.
Lap Infants Under Two
Most airlines let a child under two fly on a parent’s lap for free or at a reduced fare on domestic routes, but they want proof the child qualifies. A birth certificate, passport, or government-issued photo ID all work as proof of age, and the airline can ask for it at any point during the trip. Without it, the airline can require you to buy a separate ticket for the child.3Southwest Airlines. Traveling with an Infant A certified birth certificate slipped into a carry-on covers this and any other age question that comes up.
Discounted Child Fares
Some carriers sell tickets at a child rate for specific age ranges. If you bought one, expect a gate agent to ask for verification. A birth certificate or school-issued photo ID clears it in seconds. The TSA officer won’t care, but a fare dispute at the counter can eat your boarding window.
If Your Child Is Flying Alone
Unaccompanied minor service adds paperwork and cost. Airlines generally require the service for children between 5 and 11. From 12 (or 15 on some carriers) up through 17, the airline treats the child as a young adult who can travel without the special escort unless a parent requests it. Children under 5 typically cannot fly unaccompanied at all.4U.S. Department of Transportation. When Kids Fly Alone
At check-in you fill out an unaccompanied minor form with the name, address, and phone number of the adult dropping the child off and the adult picking them up. The airline will only release the child to the person named on that form, so a last-minute substitute has to be added to the paperwork before the flight.4U.S. Department of Transportation. When Kids Fly Alone Expect a separate fee from the airline on top of the ticket price; the amount varies by carrier and is worth checking before you book.
Single-Parent Trips and Custody Situations
No federal law requires a consent letter for domestic air travel, and Puerto Rico is domestic. The TSA doesn’t ask for one, and airlines generally don’t either. Still, if you’re flying with your child without the other parent, a brief signed letter from the other parent stating they’ve given permission heads off awkward questions, especially if the trip could later be disputed.
If you have sole custody, a copy of the custody order does the same job.5USAGov. International Travel Documents for Children That guidance is written for international trips, but the practical logic carries over: it’s faster to show a document than to explain a custody arrangement to an airline employee. Notarization isn’t required for domestic travel, though it adds weight if anyone questions the letter.
What Screening Actually Looks Like With Kids
The officer checks the adult’s ID and boarding pass. Your child walks through without a separate document check. From there, a few accommodations make the process easier.
For Children 12 and Under
Kids 12 and under can keep their shoes, light jackets, and headwear on during screening.6Transportation Security Administration. Traveling with Children If the child uses the body scanner, light jackets come off and go on the X-ray belt. Children aren’t separated from a parent or guardian during screening. Infants must come out of strollers and car seats and be carried through the walk-through metal detector, but babies in slings or soft carriers can usually stay in them.
Baby Formula, Breast Milk, and Baby Food
Formula, breast milk, toddler drinks, and baby food, including puree pouches, are exempt from the 3.4-ounce liquid rule. You can bring reasonable quantities, and they don’t need to fit in a quart-sized bag.6Transportation Security Administration. Traveling with Children Tell the officer at the start of screening and pull the items out of your carry-on for separate inspection. Ice packs and freezer packs used to keep these items cold are allowed too, whether or not breast milk is present.
PreCheck With Kids
If you have TSA PreCheck, children 12 and under automatically join you in the expedited lane. No separate enrollment or Known Traveler Number for the child.7Transportation Security Administration. TSA PreCheck for Families For teenagers 13 through 17, the PreCheck indicator has to appear on their boarding pass, which means the adult and teen need to be on the same reservation.
What to Have in Your Carry-On
- The adult’s REAL ID-compliant license, passport, or other accepted ID
- The child’s birth certificate if you’re flying with a lap infant or bought a child fare
- Printed or digital boarding passes for everyone in the party
- An unaccompanied minor form if the child is flying without a parent or guardian
- A consent letter or custody order in single-parent or guardianship situations
- Formula, breast milk, or baby food packed for easy removal at screening