Fees, carrier sizes, weight limits, and the one airline that stands out for pet owners — everything you need to know before you book
More Americans are refusing to leave their pets behind when they travel, and airlines have responded with structured policies that make in-cabin pet travel more predictable than ever. But the rules are specific, the spots are limited, and the fees add up fast.
Here is what you need to know before you book.
The Basics Apply Everywhere
Regardless of which airline you fly, the core requirements are largely the same across major U.S. carriers.
Your pet must be small enough to fit in an FAA-approved, ventilated, leak-proof carrier that slides under the seat in front of you. Most airlines enforce a combined weight limit of around 20 pounds for the pet and carrier together. Soft-sided carriers are strongly recommended because they compress slightly to fit tight under-seat spaces.
Once you're at the airport and on the plane, your pet stays zipped inside that carrier the entire time — no exceptions.
How the Major Airlines Compare
Most major carriers charge $150 each way for an in-cabin pet. Alaska Airlines is the outlier at $100, and it has earned a reputation among pet travelers for flexibility and staff familiarity with animals.
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Read more →Here is how the four main carriers stack up:
United Airlines charges $150 one way and allows carriers up to 18″ x 11″ x 11″. Notably, United offers an “extra seat” option that allows passengers to travel with up to two pets.
American Airlines also charges $150 with the same maximum carrier dimensions of 18″ x 11″ x 11″. The airline now allows one pet carrier in addition to a full-size carry-on or personal item.
JetBlue charges $150 one way with a slightly smaller maximum carrier size of 17″ x 12.5″ x 8.5″. Pet owners earn TrueBlue loyalty points when traveling with their animals, though pets are not permitted in Mint business class.
Alaska Airlines charges $100 one way with a carrier maximum of 17″ x 11″ x 9.5″ and is widely regarded as the most pet-friendly major U.S. carrier.
What Could Catch You Off Guard
Even if your pet meets all the requirements, there are a few things that trip up first-time pet travelers.
Limited spots per flight. Airlines typically allow only four to eight pets per flight. If you wait until the last minute, you may be out of luck regardless of your pet's size.
International travel is a different story. Many countries, including the United Kingdom and Australia, do not allow pets to arrive in the cabin at all. Even if your airline permits in-cabin pets, your destination country may require the animal to travel as cargo.
Emotional Support Animals no longer get a pass. Airlines stopped recognizing Emotional Support Animals as service animals several years ago. If your pet is not a trained service animal, it travels under standard pet policy and pays the standard fee.
Health paperwork may be required. For international routes or certain domestic destinations like Hawaii, you will need a USDA-endorsed health certificate and proof of rabies vaccination.
The Bottom Line
Flying with a pet in 2026 is entirely manageable if you plan ahead. Book early to secure one of the limited pet spots on your flight, invest in a quality soft-sided carrier that meets your airline's dimensions, and verify your destination's entry requirements well before departure.
If you have flexibility on which airline you fly, Alaska Airlines currently offers the lowest fees and the most accommodating reputation among frequent pet travelers.
