Book your pet's spot the moment you buy your own ticket. US airlines cap the number of animals allowed per flight, and once that limit is hit, you're out of luck. Call the airline directly (most don't let you add a pet online), pay the fee—typically $95 to $150 each way for a carry-on pet—and confirm your dog or cat fits in an approved under-seat carrier. If your pet is too big for the cabin, your options narrow fast: most major US airlines have stopped flying pets in cargo, so you'll be looking at pet-shipping services or a road trip instead.
Cabin, Cargo, or Ground: Know Your Options First
There are three ways a pet travels by air, and the right one depends almost entirely on your pet's size.
- In-cabin (carry-on): Small dogs and cats that fit in a soft-sided carrier under the seat in front of you. This is what most travelers use, and it's the safest option for your animal.
- Checked baggage / cargo hold: Larger pets in a hard kennel in the climate-controlled hold. This has largely disappeared from US carriers. Delta and United no longer accept pets as checked baggage for most passengers, and American limits it heavily. Alaska Airlines still offers it on many routes.
- Cargo shipping: Booked through a separate freight/pet-shipping program (like United's PetSafe for military and diplomatic families). Expensive—often $500 to $1,000+—and requires a professional shipper for many bookings.
If your pet weighs more than roughly 20 pounds combined with the carrier, plan on cargo shipping or driving. The comfortable cabin option simply won't work.
What It Costs: 2026 Pet Fees by Airline
Pet fees are one-way and charged on top of your own ticket and any checked-bag fees. They rose across the board in 2025, so budget for the current numbers, not what you paid three years ago.
| Airline | In-cabin fee (each way) | Pets per passenger | Notes |
|---|---|---|---|
| American | $150 | 1 carrier | Carrier counts as your personal item or carry-on |
| Delta | $95–$150 | 1 carrier | Carrier is your carry-on; no cargo for most flyers |
| United | $150 | 1 carrier (up to 2 pets if you buy a second seat) | Carrier counts as carry-on item |
| Southwest | $125 | 2 pets per carrier | See the Southwest baggage policy for how the carrier counts |
| JetBlue | $125 | 1 carrier | Earns TrueBlue points; limit 6 pets per flight |
| Alaska | $100 | Varies | Still offers cargo/checked pet on many routes |
One thing to watch: on most airlines, the pet carrier counts as your carry-on or personal item. So if you bring a pet in the cabin, you may only get one other bag onboard. Factor that into your packing.
Carrier Rules That Actually Get Enforced
Gate agents check carriers, and they turn people away. The universal rule: your pet must be able to stand up, turn around, and lie down comfortably, and the carrier must fit fully under the seat in front of you.
Soft-sided carriers are the safe bet because they squish to fit. Typical maximum dimensions run around 18" long x 11" wide x 11" high, but each airline differs and bulkhead/window rows sometimes have smaller under-seat space. Check your specific aircraft's dimensions before you buy a carrier.
- Your pet must stay inside the carrier for the entire flight—no lap time, no bathroom trips in the cabin.
- The carrier must be leak-proof and ventilated on at least two sides.
- You cannot put the carrier in an overhead bin. It goes under the seat.
- Most airlines require pets to be at least 8 weeks old and weaned.
If your dog whines, barks, or scratches constantly, a gate agent can deny boarding. Do a few practice runs in the carrier at home before travel day, and don't feed a large meal right before the flight.
Service Animals vs. Emotional Support Animals: The Big Change
This trips up a lot of travelers who haven't flown with a pet since before 2021. The DOT rewrote the rules, and airlines are strict about them now.
Trained service dogs (dogs individually trained to do work for a person with a disability) fly free in the cabin. You'll need to submit the DOT Service Animal Air Transportation Form in advance—usually 48 hours before departure. The dog must fit within your foot space and can't block an aisle.
Emotional support animals are no longer recognized as service animals under DOT rules. As of the 2021 change, airlines treat ESAs as regular pets, meaning they pay the standard pet fee and follow all the size/carrier rules above. There's no free ESA travel anymore, and no airline is required to accept a letter from your therapist.
Don't try to pass a pet off as a service animal. Airlines can require the DOT form, ask what task the dog is trained to perform, and deny transport if the answers don't add up. Fraudulent claims can get you banned.
Health Documents and Destination Rules
For domestic flights, most airlines don't require a health certificate, but some do for certain routes, and Hawaii has strict quarantine rules for animals arriving from the mainland. Rule of thumb: carry a recent rabies vaccination record and a health certificate dated within 10 days of travel. It costs $50–$100 at the vet and prevents a very bad day at the airport.
International travel is a different animal entirely. Requirements vary wildly by country—the EU, UK, and many others require microchips, specific rabies timelines, and USDA-endorsed paperwork that can take weeks to arrange. Start at least a month out and check both the destination country's rules and the USDA APHIS Pet Travel site.
A note on breeds and weather: snub-nosed (brachycephalic) breeds like bulldogs, pugs, and Persian cats face the highest risk of breathing problems in flight, and some airlines restrict them entirely. Airlines also impose temperature embargoes on cargo pets during summer and winter extremes.
Day-of-Travel Tips From Someone Who's Done It
- Arrive early. You often have to check in at the counter to confirm the pet and pay the fee—you can't do it at a kiosk. Give yourself an extra 30–45 minutes.
- Walk your dog right before security. There's no easy bathroom option once you're airside, though many larger airports now have indoor pet relief areas past security.
- You'll carry the pet through the metal detector. At the TSA checkpoint, you take your pet out of the carrier, send the empty carrier through the X-ray, and walk your pet through the scanner in your arms (or on a leash). Speed this up with TSA PreCheck.
- Freeze a small water dish so it doesn't spill at the gate but melts to drinkable water in flight.
- Book direct flights. Connections mean more stress for your pet and more chances for a missed connection. If you do miss a connection, having a pet limits your rebooking options since the next flight may already be at its pet limit.
What You're Owed if Things Go Wrong
Your pet's fee is separate from your fare, and the DOT's protections are worth knowing. Under the 2024 DOT refund rule, if the airline cancels your flight or makes a significant change and you choose not to travel, you're entitled to an automatic cash refund of your ticket. That refund should include the pet fee, since the service wasn't provided—if it doesn't, push back.
If you're involuntarily bumped, the standard denied-boarding rules apply to you (up to $1,075 for a 1–2 hour domestic delay, up to $2,150 beyond that), but the airline should also rebook your pet on your new flight—confirm the pet limit isn't full before you accept.
Note that the DOT's $3,800 domestic baggage liability limit does not cover pets in the cabin the same way it covers luggage. If an airline mishandles a pet in cargo, that's governed by their contract of carriage, which typically limits their liability. When an airline breaks its own stated policy or mishandles your booking, you can file a DOT complaint.
Frequently Asked Questions
Can I buy a second seat for my larger dog?
Generally no—US airlines don't let you buy an extra seat to place a large pet carrier on the seat beside you. The carrier must fit under the seat. The exception is that some airlines let you bring a second pet if you purchase a second seat for yourself and place both carriers under the seats. Larger dogs need cargo shipping or ground transport.
Does the pet fee count toward my checked bag allowance?
No. The pet fee is a standalone charge, and it usually doesn't waive any bag fees. On most airlines, the pet carrier counts as your carry-on or personal item, so you may lose a piece of your normal cabin allowance.
Are pets allowed to fly if I'm traveling with an infant?
Yes, but foot space gets tight. A pet carrier and an infant both take up your under-seat and lap area, so plan carefully—see our guide on flying with a baby for how those rules interact.
What happens if the flight is full of pets already?
You won't be allowed to board with your pet, even if you paid. That's why you must reserve the pet spot when you book, not at the airport. If the airline oversells its pet limit and can't take yours, ask to be rebooked on the