Southwest Pet Policy: Fees, Carrier Rules, and How to Book (2026)

Southwest pet policy is Southwest Airlines' in-cabin program for small, vaccinated domestic cats and dogs on U.S. domestic flights. As of August 2026, pets must be at least eight weeks old, travel in an approved under-seat carrier, and cannot fly in cargo, to or from Hawaii, or internationally. The Pet Fare is $125 per carrier each way on the U.S. mainland and $35 between Hawaiian Islands, per Southwest Airlines. Six pet carriers are allowed per flight.

Last updated: August 18, 2026. By Animal Passport. Rules, fees, and carrier limits come from Southwest Airlines official Help Center articles and Contract of Carriage. This guide is informational only—not veterinary or legal advice. Animal Passport is a private digital livestock and pet identity platform; it is not a government-issued pet travel document and does not replace airline or state entry requirements.

What Is the Southwest Pet Policy?

The Southwest pet policy allows ticketed passengers to bring one pet carrier per person into the aircraft cabin on domestic Southwest Airlines flights. Each carrier may hold up to two small cats or dogs of the same species. Southwest Airlines states that pets must be vaccinated, at least eight weeks old, and remain inside a leak-proof, well-ventilated carrier for the entire journey—from the gate area through boarding, the flight, and deplaning.

Unlike many U.S. carriers, Southwest does not transport pets in the cargo hold. The airline's Contract of Carriage explicitly prohibits pets in aircraft cargo compartments and limits cabin pet carriers to six per flight on a first-come, first-served basis, per Southwest Airlines Contract of Carriage.

Southwest Pet Policy at a Glance

• Eligible animals: Small, vaccinated domestic cats and dogs only (Southwest Airlines Help Center, 2026).
• Minimum age: Eight weeks (Southwest Airlines Help Center, 2026).
• Cabin only: No checked or cargo pet transport (Southwest Airlines Contract of Carriage).
• Pet Fare: $125 per carrier each way on the U.S. mainland; $35 between Hawaiian Islands (Southwest Airlines Optional Travel Charges, 2026).
• Per passenger: One pet carrier; up to two pets of the same species per carrier (Southwest Airlines Help Center, 2026).
• Per flight cap: Six pet carriers maximum, first-come, first-served (Southwest Airlines Contract of Carriage).
• Booking: Pet reservations must be made by phone; fare paid at the airport ticket counter (Southwest Airlines Contract of Carriage).
• Refund: Pet Fare is refundable if you cancel the reservation (Southwest Airlines Help Center, 2026).

Who Can and Cannot Fly Under the Southwest Pet Policy

Eligible travelers and pets

Any ticketed adult passenger may travel with a pet carrier, provided space is available on the flight. Unaccompanied minors cannot travel with a pet, according to Southwest Airlines. Pets must be healthy, harmless, inoffensive, and odorless, and must not require special attention during the flight, per the Southwest Airlines Contract of Carriage.

Routes where pets are not accepted

Southwest's destination rules restrict pets on several itineraries:

• Hawaii to or from the continental U.S.: Pets are not allowed (Southwest Airlines Help Center and Contract of Carriage).
• Between Hawaiian Islands: Pets are accepted at the reduced inter-island Pet Fare of $35 per carrier each way (Southwest Airlines Optional Travel Charges, 2026).
• International flights: No pets on international flights or any itinerary that includes an international segment (Southwest Airlines Help Center, 2026).
• Puerto Rico: Pets may be permitted on domestic routes, but Southwest notes that specific requirements may apply; passengers must research local animal laws (Southwest Airlines Help Center, 2026).

Pet Fare, Booking, and Check-In

How much does Southwest charge for pets?

Southwest Airlines lists a one-way Pet Fare of $125 per pet carrier on U.S. mainland routes and $35 per pet carrier on flights between Hawaiian Islands, on its Optional Travel Charges page as of August 2026. Pricing is subject to change. Southwest also sells its own branded pet carrier at airport ticket counters for $58 per carrier, separate from the Pet Fare.

How to book a pet on Southwest

Pet reservations cannot be added online alone. Southwest Airlines Contract of Carriage states that pet reservations can only be booked by calling Southwest at 1-800-I-FLY-SWA (1-800-435-9792). Because each flight accepts at most six pet carriers, Southwest recommends calling early to secure a spot.

On travel day, you must check in at the airport ticket counter, pay the Pet Fare by credit card, and complete pet check-in before proceeding to the gate, per Southwest Airlines airport guidance.

1. Book your passenger ticket on Southwest.com or by phone.
2. Call Southwest (1-800-435-9792) to add a pet reservation to your itinerary.
3. On departure day, pay the Pet Fare at the ticket counter before going to security.
4. At TSA, carry your pet through the metal detector while the empty carrier is X-rayed.
5. Board with your assigned group; stow the carrier under the seat in front of you for the entire flight.

Approved Pet Carriers and Size Limits

Southwest requires carriers that are specifically designed for pets, leak-proof, well ventilated, and small enough to fit under the seat in front of you. The pet—including head and tail—must remain fully inside the carrier and be able to stand up and move around with ease, according to Southwest Airlines carrier guidance.

Your pet carrier counts as either your personal item or your carry-on bag—you may board with the carrier plus one personal item, or the carrier plus one standard carry-on, but not both a personal item and a full carry-on in addition to the carrier, per Southwest Airlines.

Airport Security and Day-of-Travel Expectations

At the TSA security checkpoint, you will remove your pet from its carrier and carry or lead the animal through the screening device while the empty carrier passes through the X-ray machine, according to Southwest Airlines airport pet guidance. All pet carriers may be searched.

Pets must stay in the carrier at all times in the gate area, during boarding and deplaning, and throughout the flight. Pet relief areas are available at Southwest-served airports, but Southwest will not hold a flight while you use one. Pet strollers may be checked for standard baggage fees; Southwest does not assume liability for stroller damage.

Onboard Rules, Seating, and Behavior

During the flight, your pet carrier must remain stowed under the seat in front of you. Southwest prohibits pets from occupying a passenger seat, sitting in exit rows, or sitting in the first row (bulkhead), per Southwest Airlines onboard pet guidance. Aisle seats may offer less under-seat space; Southwest recommends soft-sided carriers for flexibility.

Southwest may deny boarding or remove a pet that shows disruptive behavior, including excessive barking or whining, growling, biting, jumping, lunging, or urinating or defecating in the cabin or gate area, according to Southwest Airlines Help Center articles. Animals with heart disease, anxiety disorders, or brachycephalic (short-nosed) airway anatomy may face higher complication risk during flight; Southwest advises consulting your veterinarian before travel.

Service Dogs, Emotional Support Animals, and Pets Compared

Following a U.S. Department of Transportation (DOT) rule effective in 2021, Southwest no longer accepts emotional support animals as service animals. Effective March 1, 2021, Southwest accepts only individually trained service dogs—dogs that perform tasks for a person with a disability—and charges no fee for qualified service dogs, per Southwest Airlines news release and Help Center.

Trained service dogs must be harnessed, leashed, or tethered, behave under the handler's control, and sit at the handler's feet or in their lap if no larger than a child under age two. A completed U.S. Department of Transportation Service Animal Air Transportation Form—dated on or after ticket purchase—is required; vests and ID cards alone are not accepted, per Southwest Airlines service dog guidance. Destination-specific rules apply for Hawaii, Puerto Rico, and international travel with service dogs.

Vaccination and Health Records

Southwest requires pets to be vaccinated but its published Help Center articles do not specify a mandatory health certificate for domestic mainland travel. The Contract of Carriage requires pets to be healthy, harmless, inoffensive, and odorless. For Puerto Rico and certain destinations, local animal import laws may require additional documentation beyond Southwest's baseline rules.

This is distinct from the EU Pet Passport issued under the European Union Pet Travel Scheme (PETS), which is an official veterinary document for cross-border movement within Europe. Animal Passport—the product published at animalpassport.co—is a private digital identity record using muzzle biometrics, phone-based capture, breed and age estimates, body condition scoring, and vaccination history. It is not a government-issued travel document and does not satisfy airline check-in or border-entry requirements on its own. Keeping vaccination dates organized in any reliable format, however, helps you meet Southwest's expectation that cabin pets are vaccinated. Read more on our blog.

Additional Southwest Pet Policy Details

• Rapid Rewards: Pets do not earn Rapid Rewards points (Southwest Airlines Help Center, 2026).
• Cremated remains: Cremated pet remains may be carried onboard as a personal item subject to TSA screening; they cannot be checked as baggage (Southwest Airlines Help Center, 2026).
• Assigned seats: As of 2026, all Southwest flights use assigned seating. Choose a non-exit, non-bulkhead seat with under-seat storage when traveling with a pet.
• Medical emergencies: Southwest will not administer oxygen or first aid to a pet that becomes ill in flight, and no oxygen mask is available for animals, per Contract of Carriage.

Planning Checklist Before You Fly Southwest With a Pet

1. Confirm your route accepts pets (no Hawaii mainland segments, no international legs).
2. Verify your cat or dog is at least eight weeks old, vaccinated, and fit to fly per your veterinarian.
3. Measure your carrier against Southwest's 18" × 10.5" × 10" maximum (or use the 15" × 10" × 10" Southwest-branded carrier).
4. Call 1-800-435-9792 immediately after booking to reserve one of six pet spots on your flight.
5. Arrive early for ticket-counter Pet Fare payment and TSA screening with your pet out of the carrier.
6. Pack absorbent padding, a familiar blanket, and any destination-specific health documents for Puerto Rico or other territories.

For the latest fees and policy changes, check Southwest Airlines Help Center before every trip. Airline pet rules differ from official government pet travel schemes and from private digital ID tools—know which document each authority actually requires.