Quick Answer
The cost nobody quotes you: a fee, plus a bag
Search interest in flying with a dog peaks in November and December, which is exactly when flights are fullest and the space under the seat in front of you is worth the most.
Most guides quote the pet fee and stop. The fee is the visible half. The invisible half is that on every US airline in the table below, the carrier occupies your baggage allowance: you are paying $150 to $200 for the privilege of also giving up a free bag.
Here is the other thing worth knowing before you book. Two of the biggest US carriers will not put a dog in the hold at all, which means for a large dog the answer is not “it costs more”, it is “you cannot fly them”.
How these picks were chosen
VoyageHacks read the in-cabin pet policy published by six airlines on their own sites on 24 August 2026, recorded the carrier dimensions, the one-way fee and the baggage treatment exactly as each carrier states them, and then selected carriers whose published external dimensions sit inside those limits. Nothing here was bench-tested by us: these are manufacturers’ published specifications measured against airlines’ published rules, which is the comparison that decides whether you and your dog board.
The carrier most often waved through, and the reason is a patented spring wire frame: the rear end pushes down several inches so the bag squashes into an under-seat space that its stated height would not otherwise clear. Mesh on multiple sides, locking zippers, top and side entry, washable liner. The catch: the medium footprint is too long for the tightest limit in the table below, so match the size to your airline rather than to your dog’s ego.
Check price on Amazon Live price on AmazonThe same collapsible-end design in the size that clears the strictest under-seat limits, which matters if JetBlue or an American Eagle regional jet is anywhere in your itinerary. Buy this one if your dog is genuinely small and you would rather not gamble at the gate. The catch: small is small, and a dog has to be able to stand up and turn around inside, which is an airline requirement and not a nicety.
Check price on Amazon Live price on AmazonZipped shut it is 18 x 10.5 x 11 inches, which sits inside the soft-sided allowance that United and American both publish. Unzip the side panel at the gate or in the hotel and it expands into a much larger lounging space. Self-locking zippers, plywood base, fleece bedding. The catch: 18 inches of length is over JetBlue’s 17-inch limit, and the expansion must stay zipped shut for the whole flight.
Check price on Amazon Live price on AmazonIf your dog is too big for the cabin and the airline still carries animals in the hold, this is the standard: Petmate states the Sky Kennel meets IATA requirements for live animal transport, with 360-degree ventilation, tie-down holes and the LIVE ANIMAL stickers, food and water cups and absorbent pad in the box. The catch: several major airlines no longer carry pets in the hold at all, so confirm before you buy a crate you cannot use.
Check price on Amazon Live price on AmazonThe part of the trip most people ignore is the drive to the airport, which is statistically the dangerous leg. Kurgo publishes crash-test certification for this harness for dogs up to 75 lb, with five adjustment points, all-steel nesting buckles and a seatbelt tether with a steel carabiner. The catch: it is a car restraint, not a carrier, so it does nothing for you once you are inside the terminal.
Check price on Amazon Live price on AmazonThe single cheapest way to stop a delay turning into a disaster. These sit in the bottom of the carrier and lock wetness away from the dog, which matters when a two-hour connection becomes six. Sized for a carrier floor rather than a room. The catch: they are disposable, so pack a spare and a bag for the used one, because airport bins are not where you want to be improvising.
Check price on Amazon Live price on AmazonFood-grade silicone bowls that fold flat and, unusually, come with lids, so you can fill one at a water fountain past security and carry it to the gate without it sloshing through your bag. Dishwasher safe, 12 oz each. The catch: 12 oz is a small drink for a big dog, and you cannot take water through the checkpoint, so the fill happens airside.
Check price on Amazon Live price on AmazonIn-cabin pet rules by airline, checked August 2026
Every figure comes from the airline’s own pet policy page on 24 August 2026.
| Airline | In-cabin carrier limit | Fee each way | Does it use your baggage allowance? | Pets in the hold? |
|---|---|---|---|---|
| United | Hard 17.5 x 12 x 9 in (44 x 30 x 22 cm); soft 18 x 11 x 11 in (45 x 27 x 27 cm) | $150 | Not stated on the pet page | Not offered in cabin booking flow |
| American | Soft 18 x 11 x 11 in (46 x 28 x 28 cm); hard mainline 19 x 13 x 9 in; hard American Eagle 16 x 12 x 8 in | $200 per kennel, $150 to/from Brazil | Yes. One additional item only: a personal item or a carry-on, not both | Yes, via American Airlines Cargo |
| Delta | No dimensions published. Kennel must fit under the seat in front | $150 domestic, $200 international | Yes. Kennel plus one personal item or one carry-on | Not in the in-cabin policy |
| JetBlue | 17 x 12.5 x 8.5 in (43.2 x 31.8 x 21.6 cm) | $150 | Yes. Pet and carrier count as one personal item | No. No dogs or cats carried in cargo |
| Southwest | Not published on the pet policy page | Pet Fare, published on its Optional Travel Charges page | Yes. Counts as either your carry-on or your personal item | No. No pets in the cargo compartment |
| Lufthansa | Dog or cat up to 8 kg including the container | Not published on the animals page | No. Carried as additional carry-on baggage | Yes, over 8 kg, in the air-conditioned hold |
Three things in that table deserve a second read.
The regional jet is the trap. American publishes 19 x 13 x 9 in for a hard carrier on mainline flights and 16 x 12 x 8 in on American Eagle. Book a connection that drops you onto a regional aircraft and the carrier that was legal on the first leg is not legal on the second.
Delta publishes no dimensions at all, exactly as it publishes no personal-item dimensions. In practice the under-seat space is comparable to the others, but you have no rule to point at if an agent disagrees.
Lufthansa is the outlier worth knowing about. It carries the container as additional carry-on baggage, so a European itinerary can cost you a fee without also costing you a bag.
United’s aircraft rule, and why two dogs need two seats
United publishes something the others do not: a list of aircraft where the under-seat space allows only one pet per person, covering the A319, A320, A321neo, 737-800 and 737-8 (MAX 8), and 737-900 and 737-9 (MAX 9). United also states that bringing two pets means buying two seats, next to each other, and that there are no weight or breed limits for in-cabin pets as long as the animal travels in a carrier.
That combination is unusual and generous on size, and restrictive on aircraft. Check the equipment on your specific flight, not just the airline.
What the CDC requires to enter or re-enter the United States
This is the part that ends trips, and it applies to US citizens coming home with their own dog just as much as to anyone importing one.
Every dog needs a CDC Dog Import Form receipt. The CDC states that all dogs entering the United States must be accompanied by one.
For a dog that has spent the previous six months only in countries the CDC classifies as dog-rabies-free or low risk, the CDC states no other documents are required, but the dog must still:
- appear healthy on arrival,
- have a microchip that can be read, and
- be at least 6 months old.
For a dog that has been in a high-risk country for dog rabies in the previous six months, additional rabies vaccination and documentation requirements apply, and the CDC states plainly that a dog which is not vaccinated against rabies and has been in a high-risk country in the past six months will not be allowed to enter.
Two details that catch people out:
The port of entry must match the form. The CDC states the port of entry must match the one listed on the Dog Import Form receipt. If weather or a missed connection reroutes you through a different city, that receipt no longer matches your arrival.
The microchip has to come first. A rabies vaccination given before the dog was microchipped and scanned cannot be tied to that animal, which is why the sequence matters more than the dates.
You also have to satisfy the US Department of Agriculture and the rules of your destination state, and dogs imported for resale carry further USDA requirements.
Choosing the carrier: soft, expandable or hard
Soft-sided is what you want for the cabin, and every airline here either permits or recommends it. The reason is structural: a soft carrier with a collapsible end, like the spring-wire frame on the Sherpa Original Deluxe, compresses into an under-seat space that a rigid box of the same stated size would not clear.
Expandable carriers like the Mr. Peanut’s solve the layover, not the flight. Zipped shut, it is 18 x 10.5 x 11 in and sits inside United’s and American’s soft-sided allowances. Unzipped at the gate or in the hotel, the dog gets room to stretch. It must stay zipped shut in flight.
Hard crates are for the hold, and the reference standard is the IATA Live Animals Regulations container requirement: rigid shell, ventilation on multiple sides, secure door, tie-down points, and space for the animal to stand, turn and lie down. Petmate states the Sky Kennel meets IATA requirements and ships with the LIVE ANIMAL stickers, cups and absorbent pad.
Buy this if you fly in the cabin: the Sherpa, in the size that matches your strictest airline. Skip it if JetBlue or American Eagle is on the itinerary and you were about to buy an 18-inch carrier. The alternative: the Small Sherpa, which is the sane answer for the tightest limits.
Edge cases that end trips
Snub-nosed breeds and the hold. Brachycephalic dogs (pugs, bulldogs, boxers) have well-documented breathing difficulty under heat and stress, and many airlines restrict or refuse them for hold travel for that reason. If your dog is one, the cabin is not a preference, it is the only responsible route, and that caps the dog’s size at whatever fits under a seat.
Behaviour is a boarding condition, not a formality. Southwest lists scratching, excessive whining or barking, growling, biting, lunging and toileting in the cabin or gate area as grounds for denying boarding. A dog that has never been in a carrier for six hours should practise before the airport, not at it.
Space is capped per flight. Airlines limit how many animals travel in the cabin, and Southwest recommends booking by phone in advance. A pet is not a thing you add at the gate.
Unaccompanied minors cannot travel with a pet on Southwest, which matters for families splitting up a journey.
International adds a second rulebook. The CDC governs entry to the US; your destination has its own, and some countries do not accept pets at all. United warns that some countries do not allow pets to travel and others have strict rabies rules. Start that paperwork weeks out, not days.
What changed recently
- 1 August 2024: the CDC’s current dog importation framework took effect, introducing the Dog Import Form and the universal microchip and 6-month age requirements for dogs entering the United States.
- 8 April 2025: Delta’s in-cabin pet fee structure changed, with $150 applying to domestic tickets issued on or after that date and $200 international.
Fees and rules move without much notice. The figures here were read off the airlines’ own pages on 24 August 2026, and the operator’s site is always the last word.
Sources
- United Airlines, traveling with pets , checked 24 August 2026.
- American Airlines, traveling with pets , checked 24 August 2026.
- Delta Air Lines, pet travel overview , checked 24 August 2026.
- JetBlue, traveling with pets , checked 24 August 2026.
- Southwest Airlines, pet policy , checked 24 August 2026.
- Lufthansa, travelling with animals , checked 24 August 2026.
- Centers for Disease Control and Prevention, bringing a dog into the U.S. , checked 24 August 2026.
- Centers for Disease Control and Prevention, frequently asked questions on dog importations , checked 24 August 2026.
Frequently Asked Questions
How much does it cost to fly with a dog in 2026?
In-cabin pet fees run around 150 to 200 US dollars each way on the major US airlines. United charges 150 dollars each way, JetBlue charges 150 dollars each way, Delta charges 150 dollars for domestic tickets issued on or after 8 April 2025 and 200 dollars international, and American charges 200 dollars per kennel with a lower 150 dollar fare to and from Brazil. Those are one-way figures, so a round trip roughly doubles them.
What size pet carrier is allowed in the cabin?
There is no single limit. United allows a hard-sided carrier up to 17.5 x 12 x 9 inches or a soft-sided one up to 18 x 11 x 11 inches. American allows a soft-sided carrier up to 18 x 11 x 11 inches on all flights, but only 16 x 12 x 8 inches for a hard-sided carrier on American Eagle regional flights. JetBlue caps carriers at 17 x 12.5 x 8.5 inches. Delta publishes no dimensions and requires only that the kennel fits under the seat in front of you.
Does a pet carrier count as your carry-on bag?
On US airlines, yes, and this surprises most first-time flyers. American states you may bring only one additional item with your pet, a personal item or a carry-on bag but not both. Delta states that in addition to the kennel you may bring one personal item or one carry-on item. JetBlue states the pet and carrier count as one personal item, and Southwest states the carrier counts as either your carry-on or your personal item. Lufthansa is the exception in this comparison and carries the container as additional carry-on baggage.
What are the CDC rules for bringing a dog into the United States?
Every dog entering or returning to the United States must be accompanied by a CDC Dog Import Form receipt. Dogs arriving from countries the CDC classifies as dog-rabies-free or low risk need no other documents but must still appear healthy, have a readable microchip and be at least 6 months old. Dogs that have been in a high-risk country in the previous 6 months face additional rabies vaccination and documentation requirements, and an unvaccinated dog coming from one will not be allowed in.
Can big dogs fly in the hold?
It depends entirely on the airline, and fewer carry animals in the hold than travellers assume. JetBlue states plainly that no dogs or cats are carried in cargo, and Southwest states that no pets are transported in the cargo compartment, so on those two the cabin is the only option and a large dog simply cannot fly. Lufthansa carries dogs and cats over 8 kg including the container in the air-conditioned hold as excess baggage.
How old does a dog have to be to fly?
Airlines and border rules set different floors, and you have to clear both. Southwest requires pets to be at least eight weeks old to travel. Separately, the CDC requires any dog entering or returning to the United States to be at least 6 months old, whatever the airline allows, so a puppy that meets the airline’s minimum can still be refused entry at the US border. VoyageHacks checked both rules on the operators’ own pages in August 2026.
The bottom line
Buy the carrier to your strictest airline, not your favourite one. For most people flying in the cabin that is the Sherpa Original Deluxe, in the size that clears the tightest limit on your itinerary, with DryFur pads in the bottom and collapsible bowls in your bag. If the drive to the airport is part of the trip, the Kurgo Tru-Fit is the piece that actually protects the dog.
Do not book anything until you have checked two things: the aircraft on each leg, because a regional jet can shrink the limit mid-journey, and your CDC form’s port of entry, because a reroute breaks it.
And budget for the bag you are about to lose. Since the carrier takes your personal item on most US airlines, the best personal item bags guide is worth reading backwards: what you need is the smallest bag that still carries your own kit, because the under-seat space now belongs to the dog. A luggage tracker in the checked bag frees you to watch the dog instead of the carousel.
Airline-by-airline rules live in our airline reviews , including United Airlines , American Airlines and Delta Air Lines . Everything else we pack is in the travel gear hub .