Do Babies Need a Ticket to Fly?
Domestically, no. Internationally, usually yes, and often with a fee. The exceptions are where the money and the missed flights live.
By Ryder M. · Published October 11, 2026 · Last reviewed
Disclosure: Wrap & Wander earns a commission on qualifying purchases made through links on this page, at no cost to you. It does not change which products we recommend or the order we rank them in — see how we pick and our full disclosure.
Quick picks
Ranked on the specs that decide it for a traveling parent — carried weight, packed size and fit. Tap a row to jump to the full write-up.
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 |  AmSafe CARES Child Aviation Restraint System11 oz, the only FAA-approved harness-type child aviation restraint, for children 22-44 lb and 40 in or less who can sit upright unaided — AmSafe states it installs in under 60 seconds and packs into a carry-on. | A 22-44 lb child in a purchased seat, with nothing to carry on the ground | 9.0 | |
| 2 |  Safety 1st Smooth Ride Convertible Car Seat8.8 lb and 18.88 in wide, rear-facing 5-40 lb and forward-facing 30-50 lb, certified for use on an aircraft. | The restraint that actually covers a child under 22 lb | 8.9 | $94.99 · View on Amazon #ad we may earn a commission · price as of November 12, 2026 |
The short answer
No, on US domestic flights, if the baby flies on an adult’s lap — JetBlue publishes that lap children under two on US domestic flights do not need to be ticketed, and Southwest, Delta and American all publish a free lap infant domestically. Yes, on international flights: JetBlue publishes that infant tickets are required for all international flights and that departures from an international destination to the US are assessed an infant fee. One lap infant per adult, every time, and a purchased seat from the second birthday.
What each carrier publishes
| Airline | Domestic lap infant | Age window | Per adult | Read |
|---|---|---|---|---|
| JetBlue | No ticket needed for lap children under 2 on US domestic flights; no cost to add to a reservation. Infant tickets required for all international flights | Three days old until the second birthday; doctor's letter required 3-14 days | One | 2026-10-11 |
| Southwest | Carried free of charge domestically | Over 14 days and under 2 years, with an adult 18 or older | One | 2026-09-27 |
| Delta | Infants or children under 2 can travel on the lap of an adult for free within the United States | Under 2 | Not stated on the page we read | 2026-09-27 |
| American | One infant under 2 can travel in your lap; no separate seat required unless you use an FAA-approved car seat on board | Under 2; contact Reservations if under 7 days old | One | 2026-09-27 |
| United | Not readable — United's family travel page renders its policy detail with client-side JavaScript | Not readable | Not readable | 2026-09-27 |
Each row is quoted or closely paraphrased from the airline's own published page, read on the date shown. United's detailed terms were not readable to us and we are recording that rather than borrowing another airline's rule to fill the gap.
The international exception is where the money is
Everybody knows a baby flies free. Far fewer people know that the free lap is a domestic arrangement.
JetBlue is the clearest on it: infant tickets are required for all international flights, and customers departing from an international destination to the US — with Puerto Rico and the US Virgin Islands excepted — will be assessed an infant fee that varies by international point of origin (jetblue.com, read 2026-10-11).
Note the direction of travel in that sentence. The fee is attached to departing an international destination for the US, which is the leg people have usually already paid for by the time they read about it. If your trip crosses a border in either direction, price the baby in rather than assuming the domestic rule carries over.
The second birthday is the expensive one
American publishes it plainly: children 2 and older must have a purchased seat. The trap is a round trip that straddles the birthday, and JetBlue is the only carrier we have read that publishes the solution on its own help page — if the child’s second birthday falls between the outbound and the return, buy two one-way flights, because a seat will need to be purchased for the return.
That advice is good on any airline. Check the birthday against both legs before you book a round trip, and if it falls in the middle, split the booking. Once the child is two, the whole trip changes — the restraint options, the baggage, the food — and that is flying with a toddler.
Free does not mean free of consequences
The lap infant fare is zero domestically. Two things that come with it are not.
Baggage. JetBlue publishes that lap infants do not qualify for any checked baggage allowance, while still allowing one diaper bag, one stroller and one car seat. Southwest goes further and publishes that a lap child may not check or carry on any baggage at all. So an extra person does not mean an extra bag, and planning on one is how families end up paying at a counter.
Safety. The FAA does not require a child restraint on a commercial flight, and it also states that the safest place for a child under two is in an approved restraint rather than on a lap (faa.gov, read 2026-09-27). That is the trade you are making when you take the free lap, stated in the regulator’s own words rather than ours.
If you decide to buy the seat
For a baby, that means a car seat: the Safety 1st Smooth Ride rear-faces from 5 lb, is 18.88 in at its widest point and weighs 8.8 lb. The CARES harness is lighter by an order of magnitude at 11 oz, but its published floor is 22 lb — so it is the answer for a toddler in a purchased seat, not for an infant. Delta publishes both options by name (delta.com, read 2026-09-27).
That decision has its own page at CARES harness vs car seat, the airline rules are collected at car seat on a plane, and the per-carrier detail starts at JetBlue and Southwest.
Alaska is the sixth carrier we have read end to end, and it publishes no minimum age for an infant at all — flying with a baby on Alaska Airlines has its lap infant rules, including the per-row limits set by flight number.
Every pick in full
AmSafe CARES Child Aviation Restraint System
11 oz, the only FAA-approved harness-type child aviation restraint, for children 22-44 lb and 40 in or less who can sit upright unaided — AmSafe states it installs in under 60 seconds and packs into a carry-on.
Best for: A 22-44 lb child in a purchased seat, with nothing to carry on the ground
| For children | 22-44 lb, 40 in or less, able to sit upright unaided |
|---|---|
| Weight | 11 oz |
| Approval | the only FAA-approved harness-type child aviation restraint |
| Install | the brand states under 60 seconds; packs into a carry-on |
Specs from AmSafe CARES product page, read 2026-09-27. Manufacturers revise specs without notice — check the listing before you buy.
Good at
- 11 oz: buying a seat no longer means carrying a car seat through a terminal
- The only FAA-approved harness-type child aviation restraint
- 22-44 lb, 40 in or less, able to sit upright unaided
- AmSafe states installation takes under 60 seconds
- Delta publishes the CARES harness by name as an alternative to a child safety seat
Bad at
The 22 lb floor means it is useless for exactly the age group this page is about. A lap infant is under 22 lb by definition, so if you buy a seat for a baby you are buying a car seat, not a harness. It is also no use at all on the ground.
How it scores (out of 10)
Overall 9.0 — a research score against published specs, not a test result. See how we pick.
Safety 1st Smooth Ride Convertible Car Seat
8.8 lb and 18.88 in wide, rear-facing 5-40 lb and forward-facing 30-50 lb, certified for use on an aircraft.
Best for: The restraint that actually covers a child under 22 lb
| Weight | 8.8 lb |
|---|---|
| Width | 18.88 in |
| Rear-facing | 5-40 lb, 19-40 in |
| Forward-facing | 30-50 lb, 34.4-44 in |
| Fits | three across the back seat of most vehicles |
| Harness | 5-point, front adjust; 5 harness heights, 3 buckle locations |
| Air travel | certified for use on an aircraft |
| Install | LATCH compatible |
Specs from Safety 1st Smooth Ride Convertible Car Seat Amazon listing, read 2026-10-16. Manufacturers revise specs without notice — check the listing before you buy.
Good at
- Rear-facing from 5 lb — the only option here that covers a lap-infant-aged child
- 18.88 in wide, so it fits a standard economy seat and three across in a car
- 8.8 lb
- Certified for use on an aircraft; LATCH compatible
- Also the car seat for the rideshare at the other end
Bad at
Buying a seat for a baby who would otherwise fly free is the most expensive line on this page, and then you carry 8.8 lb of seat through the terminal on top of it. The FAA does not require it; it only states that an approved restraint is the safest place for a child under two.
How it scores (out of 10)
Overall 8.9 — a research score against published specs, not a test result. See how we pick.
#ad we may earn a commission · price as of November 12, 2026
Questions parents actually ask
Do babies need a ticket to fly?
Not on US domestic flights, if the baby travels on an adult's lap. JetBlue publishes that lap children under two on US domestic flights do not need to be ticketed; Southwest publishes that a lap child is carried free of charge domestically; Delta publishes that infants under 2 can travel on an adult's lap for free within the United States; American publishes that one infant under 2 can travel in your lap with no separate seat required. International travel is different — JetBlue publishes that infant tickets are required for all international flights.
Do babies need a ticket for international flights?
Usually yes. JetBlue publishes plainly that infant tickets are required for all international flights, and that customers departing an international destination for the US — Puerto Rico and the US Virgin Islands excepted — will be assessed an infant fee that varies by point of origin. Check your own carrier's published terms for the specific route, because the fee structures differ.
How many babies can fly on one adult's lap?
One. Southwest publishes that each adult may travel with one lap child; JetBlue publishes that one lap infant per adult is allowed; American publishes that one infant under 2 may travel in your lap. If you are flying with twins, that means two adults or a purchased seat — our carriers for twins page covers the on-the-ground version of the same arithmetic.
What proof do I need that my baby is under two?
Something official, and often on paper. Southwest publishes that original or photocopied government-issued identification is the only accepted proof and that screenshots, photos and immunization records are not accepted. JetBlue lists a passport, a birth certificate with copies accepted on domestic travel, or an immunization record. The two carriers disagree on immunization records, which is the clearest possible argument for carrying a birth certificate.
What happens if my baby turns two during the trip?
You need a purchased seat for the return. JetBlue publishes the workaround directly: if the child's second birthday falls between the outbound and the return, buy two one-way flights. American publishes that children 2 and older must have a purchased seat. This is the single most common expensive surprise in infant air travel.
Is a free lap infant actually free?
Domestically, generally yes for the fare — but taxes may be due outside the US and an infant fee applies on international departures to the US on JetBlue. There is also the hidden cost: a lap infant usually gets no checked baggage allowance. JetBlue publishes that lap infants do not qualify for any checked baggage allowance, and Southwest publishes that a lap child may not check or carry on any baggage at all.
Sources
- JetBlue — traveling with lap infants — read 2026-10-11
- Southwest Airlines — traveling with an infant — read 2026-09-27
- Southwest Airlines — lap child documentation — read 2026-09-27
- Delta Air Lines — infant travel — read 2026-09-27
- American Airlines — traveling with children — read 2026-09-27
- United Airlines — flying with kids and family boarding — read 2026-09-27
- FAA — does the FAA require children on commercial flights to be in child restraint systems? — read 2026-09-27
- AmSafe — CARES Child Aviation Restraint System — read 2026-09-27
Every figure on this page traces to one of the sources above. Airline policies and manufacturer specs change without notice — check the primary source before you rely on a number.
Read next
- Flying With a Baby on JetBlue
JetBlue's published infant rules: a three-day minimum, a doctor's letter to 14 days, one lap infant per adult, and what a lap infant may and may not bring.
- Flying With a Baby on Southwest
Lap child age and ID rules, the free stroller and car seat allowance, and the two rules that surprise people.
- Flying With a Baby: Documents
What the big four US airlines publish about lap-child documentation — and the one rule strict enough to ruin a morning if you miss it.
- Flying With a Toddler
What changes when a lap infant becomes a ticketed toddler: the purchased seat, the 22 lb restraint threshold and the gear that replaces a bottle.
- Do You Need a Car Seat on a Plane?
Not required, strongly recommended: what the FAA publishes, what counts as approved, and what each airline states.
- Flying With a Baby on Frontier Airlines
Frontier's published infant rules: lap infants free from 7 days to 2 years, one per adult, a boarding pass required, a second free personal item for the diaper bag, free stroller and car seat checking - and minimum seat widths of 17.4 in and 16.5 in that most car seats exceed.
More in Flying With a Baby, or start from the front page.