International travel with kids: a checklist for ages 2–6

For an international trip with a child of 2 to 6, pack the documents first: a passport for each child, and a consent letter if only one parent flies. Then the cabin bag: the children’s medicine, snacks, a change of clothes each, things to do on the flight, and a night-light for the first nights in a new time zone.

The story

It’s a night flight to another continent, and the clock where you land is six hours behind home. You fly alone with the two of them, two and five years old; their father joins you at the end of the week. At check-in, the agent opens three passports, one for each of you, and the five-year-old asks why her photo is so serious. In the pouch with the passports is the letter their father signed, saying they travel abroad with you, with his permission. Nobody asks for it today, and you keep it in the pouch for the way back.

Each child has a seat of their own: at two, the youngest is too old to fly on your lap. Each also has a small backpack: a few new stickers, a coloring book, a favorite stuffed animal, and headphones that fit a small head. You carry the rest. At security, you take out the children’s fever medicine, the liquid one in its big bottle, and tell the officer; it’s checked and handed back.

The plane takes off at bedtime. The two-year-old drinks water from a cup with a lid during the climb, and falls asleep in his pajamas before the meal comes. The five-year-old watches a cartoon, then sleeps across her seat and your lap. An hour before landing, the juice goes over the two-year-old’s shirt: the spare is in the cabin bag, and so is yours.

You land in the morning, and in the hotel room there’s a crib for the youngest, asked for when you booked. That night both children are awake and hungry at three in the morning, wide awake, because at home it’s already morning. Crackers from the cabin bag, a night-light, a story read twice, and they sleep again. The next day you keep them outside in the daylight until a normal bedtime.

An international trip with small children comes down to their documents, their medicine, and the cabin bag for the flight and the first two nights. Pack a passport for each, any letter they need, and their things for a long night, first.

What to pack for international travel with kids

Pack each child’s documents and cabin bag first: those are the things you can’t buy when you land.

Documents, for each child

A passport of their own: every child needs one, at any age. Check the expiry date when you book, and apply weeks ahead if it’s close.
A consent letter or travel authorization, if only one parent flies, or the children travel with grandparents or friends: see Good to know for what four countries ask.
A copy of a custody order or a death certificate, if either applies: border officers may ask instead of a letter.
A visa or a travel authorization, if the country asks for one: children need their own.
Travel insurance that names each child, and the pediatrician’s phone number.

Medicine, in the cabin bag

A fever and pain reliever in a children’s dose, with the measuring syringe or cup: the night after a long flight is no time to look for a pharmacy.
Any medicine the children take every day, in its box, with the prescription and a few days extra: flights get delayed.
A thermometer, adhesive bandages, and something for an upset stomach, as your pediatrician suggests.
Liquid medicine over 100 ml in its bottle, with the prescription: take it out at security and tell the officer.

The cabin bag, for each child

A small backpack they carry themselves: stickers, a coloring book, crayons, and one new toy saved for the flight.
Headphones made for children, and a tablet with films downloaded at home: the plane’s screens can be too big or too loud for small heads.
The stuffed animal or blanket they sleep with: a familiar thing on the plane and in a hotel bed.
Snacks they already know, and an empty cup with a lid to fill after security: meals come at odd hours.
Pajamas for a night flight, and a full change of clothes each, plus a top for you: juice spills.
Something to chew or drink for take-off and landing, when the change in pressure can bother small ears.
Diapers or pull-ups and wipes for the youngest, enough for the whole trip and a few hours more.

For the hotel and the time zone

A night-light and a book you can read twice: the first nights, small children wake at their home time.
Snacks for the night they wake up hungry at 3 a.m.
A crib or a bed rail for the youngest, asked for when you book: hotels often have only a few.
A light stroller that folds, or a carrier for a two-year-old: long airport walks, and a bed for naps on the first day.

Phone and money

An eSIM or a roaming plan, set up at home: a map and a taxi app work from the airport, with tired children in hand.
Photos of each child’s passport on your phone, where you can open them offline.

Good to know

Each child’s documents: every child needs their own passport, or their own ID card where one is accepted, and the country you visit may also ask children for a visa or travel authorization; in the EU, each country decides whether a child traveling with one parent needs a signed authorization, and a country you only pass through may ask for it too, says Your Europe (checked October 19, 2026).
One parent, or someone else: for the US, a child traveling with only one parent may need a letter of consent from the other, preferably in English and notarized, says USAGov. Canada recommends one in the same cases: it isn’t legally required, but officials or airlines may ask, says travel.gc.ca. Brazil requires a travel authorization whenever a Brazilian child leaves the country with only one parent, with someone else, or alone, at departure only (Federal Police, in Portuguese). Mexico asks for a SAM form when a Mexican child leaves the country alone or with an adult who isn’t a parent, not with one parent (INM, in Spanish) (all checked October 19, 2026). For other countries, ask the embassy of the country you visit and of the child’s own.
Medicine at security: liquid medicines may go in the cabin bag over 100 ml (3.4 oz), in reasonable amounts for the trip; tell the officer, who may inspect them, says the TSA. In the EU, the 100 ml limit doesn’t apply to medicines, says Your Europe. On international flights from Brazil, you may carry liquid medicines over 100 ml in the amount the flight needs, layovers included, with a prescription, says ANAC (in Portuguese) (all checked October 19, 2026).
Seats: under 2, a child can usually fly on an adult’s lap; from 2, children usually need a seat of their own. A car seat certified for aircraft can go on that seat, and the FAA certifies one harness for children who weigh 22 to 44 lb (10 to 20 kg) and are up to 40 in (102 cm) tall, says the FAA (checked October 19, 2026). Ask your airline which seats a car seat may use.
Health: ask your pediatrician about the trip a few weeks before, and whether the children need any vaccines for the country you visit.
The posts that go with it: with a baby under 2, see what to pack when flying with a baby; for your own documents, money, and phone, what to pack for your first international trip.

Questions

Does a child need a passport to travel internationally?

Yes: every child needs their own passport, at any age, or their own ID card where one is accepted. Some countries also ask children for a visa or a travel authorization, so check for each child.

Do I need a consent letter to travel abroad with my child alone?

Often, yes: the US and Canada advise a signed letter from the other parent, and in the EU each country decides. Brazil requires a travel authorization for Brazilian children leaving with one parent; Mexico asks for its SAM form only when a Mexican child leaves alone or with an adult who isn’t a parent.

Can I bring children’s medicine on a plane?

Yes: liquid medicines may go in the cabin bag over 100 ml (3.4 oz). Take them out at security and tell the officer; the US allows reasonable amounts for the trip, and Brazil the amount the flight needs, with a prescription.

Does a 2-year-old need a seat on a plane?

Yes, usually: from 2, children need a seat of their own. A car seat certified for aircraft can go on it, and the FAA certifies one harness for children of 22 to 44 lb (10 to 20 kg).

How do I help my child with jet lag?

Plan for the first nights: small children often wake at their home time, hungry. Keep snacks and a night-light by the bed, and spend the next day outside in the daylight until a normal bedtime.