Flying With a Toddler: What Goes in the Bag

The question is not what to bring. It is which bag it is in.

On a plane with a small child you have three bags doing three completely different jobs: the one under the seat in front of you, the one in the overhead bin, and the one you checked. Only the first is reachable when the seatbelt sign is on — which is precisely when things go wrong. Almost every flying-with-a-toddler disaster is really a packing-location error.

So: three bags, three lists.

The bag under the seat

This is the trip. Everything in it has to be findable one-handed, in dim light, with a child on your lap.

• Diapers: roughly one per hour of door-to-door travel, plus two. Count the whole journey, not the flight. A three-hour flight is usually an eight-hour day.
• Wipes, more than the diaper count suggests. They are also the napkin, the washcloth and the tray-table cleaner.
• Two full changes of clothes for the child, socks included.
• One clean shirt for you. This is the item nobody packs and everybody needs. When a toddler is sick or a drink goes over, it lands on the adult holding them. A child in a stained shirt is fine — children are always in stained shirts. An adult in one, for the next six hours plus baggage claim and the taxi, is a bad day.
• A wet bag, or a couple of zip-top bags, for whatever the change produced.
• Snacks that are dry, plain and slow to eat. Raisins, breadsticks, dry cereal. Not the exciting new snack you have never tried before, and nothing that needs a spoon.
• A familiar cup or bottle, emptied before security.
• The comfort object. If a duplicate exists and you can get one before you travel, do, and keep the spare in the checked bag. If it is one of a kind, it never leaves this bag.
• Any medication, in its original packaging.

The security rule worth knowing before you get in line

The 3.4oz liquid limit does not apply to any of it.

As of August 2026, the TSA classifies formula, breast milk, toddler drinks and baby food — puree pouches included — as medically necessary liquids. They are allowed through in quantities over 3.4oz, and they do not have to fit inside the quart bag. Three parts of that rule surprise people:

• Your child does not have to be with you. You can carry breast milk or formula through security travelling alone.
• Ice packs, freezer packs and gel packs are covered too — including when they are not currently cooling anything.
• You can decline the X-ray. If you would rather the milk was not screened that way, say so; you and the liquid get additional screening instead.

What you do have to do is tell the officer at the start of screening and take those items out of the bag to be screened separately. Doing that first, rather than after somebody spots a large bottle on the belt, is the difference between a two-minute conversation and a bag search with a queue behind you.

Check the TSA’s traveling-with-children page before you fly. Rules do change, and this is ninety seconds well spent.

Ears: the drink is for landing

The standard advice is to feed on takeoff. It is half right, and it is aimed at the wrong half of the flight.

The pressure change that hurts is the one on descent. On the way up, air trapped in the middle ear expands and vents outward fairly easily. On the way down the outside pressure rises and the eustachian tube has to open inward to let air back in — which is harder, especially in a small child, whose tubes are narrower and more horizontal than an adult’s, and harder still if they have a cold.

So keep something to suck, chew or drink for the descent specifically. A bottle, a cup, a snack, a pacifier — whatever they will actually take. If they sleep peacefully all the way down and then wake up screaming in the last twenty minutes, that is what happened.

Entertainment that does not need charging

A tablet is fine. It is also the thing that runs out first and the thing that cannot be taken away without a scene. Everything below buys you fifteen to thirty minutes, and none of it needs a battery.

• A roll of painter’s tape. It is the best airplane toy there is. It tears by hand, sticks to the tray table and the window and a shoe, peels off without leaving a mark, and a toddler will happily make a mess with it for a long stretch. One roll costs less than a coffee.
• Stickers, and a plain notebook to stick them into
• Two lift-the-flap books — one they know, one they have not seen
• Twist-up crayons and paper. Not pencils, which snap and then roll under someone else’s seat.
• A few small figures in a zip-top bag
• An empty container with a lid they can nearly open

The pacing matters more than the contents. Do not hand everything over at once. Keep the items in separate bags and produce one every twenty to thirty minutes. Hold one genuinely new thing back for the last hour, when everything else has stopped working.

The overhead bag

Everything here is a spare of something below. You can get to it — just not immediately.

• The third change of clothes
• The rest of the diapers and a second pack of wipes
• More snacks
• Formula, milk, and anything that needs making up
• Two large plastic bags: one for wet clothes, one for the moment you need a bag and there is not one

The checked bag

Only things you could genuinely replace. Never the medication, never the comfort object, and never every diaper and wipe you own with none in the cabin. Bags get delayed, and a delayed bag is an inconvenience right up until it contains the only thing that gets your child to sleep.

Two things worth putting in it:

• A sheet, sleep sack or blanket from their own bed. Unwashed, so it smells like home. Unfamiliar rooms are the actual reason nobody sleeps on the first night, and this is the closest thing there is to a portable bedroom.
• Whatever makes the noise they sleep to, and a nightlight.

Car seat and stroller

A stroller nearly always goes at the gate. A car seat can usually go either way, and the gate is the better option because it is handled less and stays with you right up to the aircraft door. A cheap padded bag for each is worth it, because they come back scuffed either way. Put your name and phone number on both, attached in a way that cannot be pulled off.

Whether the car seat should be on the plane at all is worth deciding on purpose rather than by cost. As of August 2026 a child under two may legally be held on an adult’s lap, but that is what the rules permit, not what they advise: the FAA recommends that children under 40 pounds fly in an approved child restraint system, on the grounds that an adult cannot reliably keep hold of a child in unexpected turbulence. An approved seat carries a label stating it is certified for use in both motor vehicles and aircraft — check for that wording before you rely on it, because a booster without a back is not approved for aircraft. The current guidance is on the FAA’s child safety seat page.

What you can leave at home

• The brand-new toy that needs explaining. Novelty is good. Instructions at 30,000 feet are not.
• The full-size diaper bag. Use a backpack. You need both hands, permanently.
• Half the snacks. It is always half.
• A fixed plan for boarding. If the child is happily running around the gate, board last. If you need the space and the time, board first. Decide there, not at home.

The cost nobody budgets for

Diapers, wipes, sunscreen, a spare pacifier, a phone charger, children’s pain reliever. Every one of those is available inside an airport at a price that assumes you have no alternative — and in that moment, you do not. Buying things you already own at home is the biggest quiet expense in family travel, and it is a packing problem wearing a price tag. The same pattern, and what to do about it, is in the budget piece.

Pack the under-seat bag as though the other two are lost. If that bag is right, everything else is logistics.

The list changes faster than the child does

The frustrating part of packing for a small child is that the list is different every few months — the diaper count drops, the snacks change, the comfort object gets replaced, and suddenly they need shoes that fit. Writing it down once is not enough. It has to be a list that carries forward and gets adjusted.

That is what PackLyst does with traveler profiles: a list per person, scaled to the length of the trip, with the things this particular child always needs already on it before you start.

Sources, and what to re-check

Two rules in this post come from federal agencies, and both are the kind that get revised. Everything else is anatomy or experience and will not move.

• Liquids for infants and toddlers — checked August 2026. Current rules: TSA, traveling with children. Re-check before any flight, and note that screening procedures at a specific checkpoint can be stricter in practice than the published rule.
• Child restraint systems — checked August 2026. Current guidance: FAA child safety seat tips. This is a recommendation, not a requirement, and airlines add their own conditions on top of it — check yours if you intend to bring a seat on board.
• The ear-pressure section is physiology and does not need re-checking.