Pet in Cabin Fee by Airline: What US Carriers Charge in 2026

The in-cabin pet fee on US airlines runs from $99 to $150 each way, per pet, as of September 2026. Frontier is the cheapest at $99. Delta, American, and United are the most expensive at $150. JetBlue and Southwest charge $125. Alaska starts at $100. None of these carriers include the fee in your fare, and every one of them charges it in each direction, so a round trip doubles the number.

That is the answer most people come here for. The rest of this article covers what the fee does and does not buy, the carrier size limit for each airline, which animals are allowed in the cabin, and the limit on how many pets a single flight will accept. That last point is the one that strands people: the fee is not the constraint, the seat count is.

All figures below were verified against each airline’s current pet-travel policy in September 2026. Airlines revise these fees without much notice, so confirm the current number on the airline’s own site before you book. Spirit Airlines ceased operations on May 2, 2026, and is not included.

In-cabin pet fee by airline

This is the one-way, per-pet fee for a small dog or cat traveling in the cabin on domestic US flights, as of September 2026.

Airline	Fee each way	Round-trip cost	Verified from
Frontier	$99	$198	Frontier pet policy
Alaska	From $100	From $200	Alaska pets policy
JetBlue	$125	$250	JetBlue JetPaws
Southwest	$125	$250	Southwest Optional Travel Charges
Delta	$150	$300	Delta pet-travel overview
American	$150	$300	American pets policy
United	$150	$300	United pet policy

Two details this table hides. First, the fee is per direction. The “round-trip cost” column is what most travelers actually pay, and it is the number worth planning around. Second, Alaska prices its fee as a range from $100 to $200 depending on the route, so treat $100 as a floor, not a guarantee.

The fee buys your pet a place in an approved carrier under the seat in front of you. It does not buy a seat. Your pet stays in the closed carrier for the entire flight, from boarding to arrival at the gate.

Carrier size limits by airline

The fee is only half the problem. The other half is whether your carrier fits. Every airline caps the carrier dimensions because the bag has to slide under the seat in front of you and stay there. A carrier that is legal on Frontier can be too tall for United.

Airline	Max carrier dimensions	Combined pet + carrier weight
Delta	18 x 11 x 11 in (soft-sided, recommended)	Not published; must fit comfortably
American	Must fit under the seat	20 lb combined
United	18 x 11 x 11 in soft / 17.5 x 12 x 7.5 in hard	Not published; pet must stand and turn
Southwest	18.5 x 8.5 x 13.5 in (or 17 x 10.5 x 10 in SW carrier)	Not published
Alaska	Must fit under the seat	Not published
JetBlue	17 x 12.5 x 8.5 in	20 lb combined
Frontier	18 x 14 x 8 in	17 lb combined

The weight rule is the one that catches people off guard. American and JetBlue both cap the pet plus the carrier at 20 pounds combined, and Frontier caps it at 17 pounds. That is the carrier and the animal together, weighed on the scale at check-in. A 15-pound dog in a 4-pound carrier is over Frontier’s limit. Weigh both at home before you commit to a fare.

Southwest and JetBlue publish the tightest height limits. JetBlue’s 8.5-inch height cap is shorter than Delta’s or United’s recommended soft-sided carriers, so a carrier bought for a Delta trip may not clear JetBlue’s under-seat space. Measure the specific aircraft’s under-seat clearance if you can, because it varies by plane.

Where an airline does not publish a combined weight limit, the practical test is the same on every carrier: your pet must be able to stand up, turn around, and lie down inside the closed carrier. A gate agent who decides your pet cannot do that can refuse to board it, and you do not get the fee back.

Which animals are allowed in the cabin

Most US airlines allow only small dogs and cats in the cabin. Frontier is the exception, and it is the widest by a distance.

Airline	Animals allowed in cabin
Delta	Dogs and cats (at least 8 weeks old, domestic)
American	Dogs and cats (at least 8 weeks old)
United	Cats and dogs only
Southwest	Small vaccinated domestic cats and dogs (at least 8 weeks old)
Alaska	Dogs and cats
JetBlue	Small dogs and cats (at least 8 weeks old)
Frontier	Dogs, cats, rabbits, guinea pigs, hamsters, and small household birds

If you are flying with a rabbit, a hamster, a guinea pig, or a small bird, Frontier is the only major US carrier on this list that will take it in the cabin. Frontier restricts those species to domestic flights, and it bans large birds, rodents like mice and rats, ferrets, reptiles, amphibians, spiders, and insects outright. The six other airlines here take dogs and cats and nothing else.

Age matters on several carriers. Delta, American, Southwest, and JetBlue require the animal to be at least 8 weeks old to fly in the cabin. Alaska sets the same 8-week minimum. Confirm the minimum age on your airline’s pet page, because a puppy or kitten under that age is refused at the gate no matter what you paid.

The real constraint: pets per flight

The fee is not what stops most people from flying with a pet. The seat count is. Every airline caps how many pets it will carry in the cabin on a single flight, and once those spots are gone, no fee will buy you another one.

• Delta allows 2 pets in Delta First and 4 in Main Cabin or Comfort on domestic flights, and books them first-come, first-served. Delta One and Business do not accept in-cabin pets at all.
• JetBlue caps each flight at 6 pets and each passenger at 2, and does not allow pets in the Mint premium cabin.
• Southwest lets each ticketed customer bring one carrier, and one carrier may hold up to two small cats or dogs of the same species.
• United, American, and Alaska each limit the number of in-cabin pets per flight and take them first-come, first-served, which is why every one of them tells you to reserve the pet as early as possible.

The practical rule: add your pet to the reservation the moment you book your own seat. On Southwest and Alaska that means calling, because you cannot always add a pet online. Waiting until check-in is how people discover the flight is already full of dogs.

What the fee does not cover

The in-cabin pet fee covers the transport, and nothing else. Three costs sit outside it.

The carrier itself is your expense. If you show up without one, Southwest will sell you a carrier at the ticket counter for $58, but most airlines expect you to bring your own. A soft-sided carrier that meets the size limit runs $30 to $80 at a pet store.

Health paperwork is separate and sometimes required. Domestic flights within the US usually do not require a health certificate, but some airlines and some destination states ask for one, and it is on you to check the destination’s rule before you fly. This is a US-domestic guide; international pet travel carries its own import rules and is out of scope here.

The fee is also non-refundable on most carriers once the pet has flown, and it does not transfer if you rebook. If your flight is cancelled and you are rebooked, the pet fee generally moves with you, but confirm that at the counter rather than assuming it.

How to pay the least to fly your pet in the cabin

Work through this before you book:

1. Check whether your pet plus carrier clears the weight limit on the airline you want. Frontier’s 17-pound combined cap is the tightest. If your pet is close, weigh it in the carrier at home first.
2. Compare the round-trip fee, not the one-way fee. Frontier at $198 round trip undercuts Delta and American at $300, but only if Frontier flies your route and your carrier fits its size limit.
3. Confirm your carrier fits the specific airline’s dimensions. A carrier that is legal on Frontier’s 8-inch height limit clears everyone. A taller carrier may not fit JetBlue.
4. Add the pet to the reservation when you book your seat, not at check-in. Spots per flight are capped and go first-come, first-served.
5. If you are flying a non-dog, non-cat pet, your only option among these carriers is Frontier, and only on a domestic flight.

The honest caveat

The cheapest fee is not always the cheapest trip. Frontier’s $99 each way is the lowest in-cabin pet fee among major US carriers, but Frontier’s base fares, seat fees, and carry-on charges can erase that saving on some routes. Price the whole itinerary, pet fee included, against a carrier like Southwest or Alaska before you decide. The pet fee is one line on the receipt, not the whole receipt.

For the bag-fee side of the same trip, see the full checked bag fees by airline guide, which covers the same seven carriers.

---

Pet fees above are as of September 2026 and were verified against each airline’s current pet-travel policy. Frontier’s $99 figure appears in Frontier’s booking flow rather than as a fixed number on its policy page, so confirm it at booking. Airlines revise pet fees without much notice. Check the airline’s own pet-travel page before you book, and reserve your pet’s spot as early as you reserve your own.