Southwest Airlines Dog Policy: Fees, Carrier Rules, and Requirements

Southwest Airlines' dog policy allows small, vaccinated dogs at least 8 weeks old to travel in the cabin, inside a carrier stowed under the seat, for a $125 Pet Fare each way on U.S. mainland flights, according to Southwest Airlines' official pet policy page. Southwest does not offer cargo transport for pets, does not allow pets on flights to or from Hawaii or on any international itinerary, and limits each flight to six pet carriers on a first-come, first-served basis.

This guide summarizes what Southwest actually publishes about flying with a dog, current as of August 2026, and separates it from unrelated topics — USDA export health certificates and Animal Passport's biometric livestock identification product — that frequently get confused with airline pet policy in search results.

Southwest Airlines Dog Policy at a Glance

Southwest's pet policy is published across several official Southwest support pages rather than one long document. Here is what those pages state.

Source: Southwest Airlines official pet policy and travel fee pages (see Sources below).

How Much Does It Cost to Fly a Dog on Southwest?

Southwest Airlines charges a $125 Pet Fare per pet carrier, each way, for travel within the U.S. mainland, and a separate $35 each-way fare for flights between the Hawaiian Islands, according to Southwest's official Optional Travel Charges page (2026). The fee is per carrier, not per animal, so if you fit two small dogs of the same species into one approved carrier, you still pay a single Pet Fare for that carrier. Southwest states that Pet Fares are nonrefundable if unused but are refundable if you cancel the reservation, and the fare must be paid at the airport ticket counter rather than online.

Southwest's fee schedule is subject to change, so confirm the current amount on Southwest's official fees page before booking, especially since third-party travel blogs sometimes cite outdated figures from prior years.

Carrier and Cabin Requirements

Southwest's official pet policy article states that "All in cabin pets must be carried in an appropriate carrier," and that the carrier counts as your carry-on or personal item for the flight. Southwest's published policy text does not list exact carrier inches or a maximum combined weight, unlike some competing airlines that publish precise dimensions. In practice, this means the carrier must be small enough to fit entirely under the seat in front of you, similar to Southwest's standard personal-item allowance.

Because Southwest's own documentation is general on carrier sizing, it is worth measuring your specific aircraft's under-seat space and choosing a carrier that is leak-proof, ventilated, and allows the dog to stand and turn around — a widely recommended baseline even where the airline itself does not spell out inches.

Behavior and Boarding Rules

Southwest's additional pet policy information page lists behaviors that can result in a pet being denied boarding, including:

• Excessive scratching, whining, or barking
• Growling, biting, or lunging
• Urinating or defecating in the cabin or gate area

Southwest also notes that pets must stay inside the carrier for the full flight, and that unaccompanied minors cannot travel with a pet.

Dogs Southwest Will Not Fly: Hawaii and International Routes

Southwest's destination information page is explicit: "Pets are not allowed to travel on flights to/from Hawaii," though "pets are accepted on flights between Hawaiian Islands." Southwest also states pets "are not allowed on international flights or any itinerary that includes an international flight." If your trip touches Hawaii from the mainland, or crosses any international border, Southwest will not carry your dog in the cabin — no exceptions are listed on the airline's official page.

For travel to Puerto Rico, Southwest directs customers to review U.S. Department of Agriculture (USDA) entry requirements before booking, since agricultural rules can apply even for domestic-feeling routes.

Service Dogs Are a Separate Policy From Pets

Southwest's dog policy for pets is distinct from its policy for trained service dogs. Since a rule change that took effect March 1, 2021, Southwest "will accept only trained service dogs for travel and will no longer transport emotional support animals," following the U.S. Department of Transportation's December 2020 final rule on traveling by air with service animals, which redefined a service animal as "a dog that is individually trained to do work or perform tasks for the benefit of a person with a disability" and removed emotional support animals from that category.

To fly with a service dog on Southwest, you must present a completed U.S. Department of Transportation (DOT) Service Animal Air Transportation Form at check-in, dated on or after your ticket purchase date. Southwest states that "a service animal vest, harness, ID card, or registration certificate will not be accepted in place of the form." Unlike pets, service dogs travel free, must be harnessed or leashed at all times, and sit at the handler's feet rather than inside a carrier during flight (carriers are used only during taxi, takeoff, and landing).

Southwest Pet Policy vs. Service Dog Policy

USDA Requirements: A Different Layer From Southwest's Policy

Southwest's dog policy governs what the airline itself will carry in the cabin. It does not replace federal or state paperwork that may apply to your specific trip. The United States Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) is the federal agency that manages health certification for pets crossing state and international lines. Most countries require a USDA-accredited veterinarian to issue a health certificate — commonly the United States Interstate and International Certificate for Health Examination for Small Animals (APHIS Form 7001) — that is then endorsed by APHIS, according to USDA APHIS's pet travel guidance. Airlines, including Southwest, may layer their own requirements on top of whatever USDA and the destination country or state require, so travelers should check both. For a step-by-step walkthrough of that federal process, see Animal Passport's guide to USDA APHIS pet travel health certificates.

Southwest's Pet Policy Is Not an EU Pet Passport

Because Southwest does not fly international routes with pets in the cabin at all, its policy should never be confused with the European Union's pet passport system, which is a government-issued travel document used for intra-EU pet movement, or with the U.S. rules for re-entering pets from abroad, which the Centers for Disease Control and Prevention (CDC) oversees for dogs. A Southwest pet reservation is an airline booking record for a seat and fare — it carries no legal or veterinary weight outside the flight itself.

This is also where Animal Passport's own product is worth distinguishing clearly, since the name invites confusion. Animal Passport is a phone-based, muzzle-biometric digital identity record for livestock — it captures a nose print, which is unique like a human fingerprint, along with owner, breed, an estimated age from a dental photograph, and a body condition score from a side-profile photo. It was used during livestock flood rescue in Pakistan in August 2025, helping farmers reclaim animals after paper ear tags washed away. It is not a substitute for a USDA health certificate, an EU pet passport, or Southwest's own booking process, and it is not a government-issued travel document. If you are flying a dog on Southwest, use Southwest's official policy and, where applicable, USDA APHIS guidance — not a livestock ID tool. You can read more about how Animal Passport's biometric ID works on the Animal Passport homepage and browse related explainers on the Animal Passport blog.

How to Book a Dog on Southwest: Step by Step

1. Book your own ticket first, since pet space is limited to six carriers per flight and is first-come, first-served.
2. Call Southwest at 1-800-435-9792 to add a pet reservation to your itinerary as early as possible.
3. Confirm your dog is at least 8 weeks old and current on vaccinations, since Southwest requires both.
4. Choose an appropriate carrier that is leak-proof, well-ventilated, and small enough to fit fully under the seat in front of you.
5. Check whether your route touches Hawaii from the mainland or includes any international leg — Southwest will not carry pets on either.
6. Arrive at the airport and go to the ticket counter, not the gate, to check in your pet and pay the Pet Fare before proceeding through security.
7. Keep your dog inside the carrier for the entire flight, including taxi, takeoff, and landing.

Frequently Asked Questions

How much does it cost to fly a dog on Southwest Airlines?

Southwest charges a $125 Pet Fare per carrier, each way, for U.S. mainland flights, and $35 each way for flights between the Hawaiian Islands, according to Southwest's official travel fees page (2026). The fee is nonrefundable if unused but refundable if the pet reservation is canceled.

Can I bring my dog in the cabin on Southwest?

Yes. Southwest allows small, vaccinated dogs at least 8 weeks old to travel in the cabin inside a carrier stowed under the seat, but only on domestic U.S. mainland routes or between the Hawaiian Islands — not to or from Hawaii from the mainland, and not on any international itinerary.

Does Southwest allow dogs in cargo?

No. Southwest's official pet policy states pets are not transported in the cargo compartment; dogs may only travel in the cabin as a carry-on pet, or not at all on that route.

What size carrier does Southwest require for dogs?

Southwest's official policy requires the carrier to fit under the seat in front of you and count as your carry-on or personal item, but Southwest's published pet policy article does not state exact inch or weight limits. Choose a leak-proof, ventilated carrier sized to your specific aircraft's under-seat space, and confirm with Southwest directly if you are unsure it will fit.

Can emotional support animals fly free on Southwest?

No. Since March 1, 2021, Southwest no longer transports emotional support animals under its service animal policy; they must fly as pets and are subject to the standard Pet Fare, carrier rules, and route restrictions.

Does Southwest allow dogs on flights to Hawaii?

No. Southwest's official destination policy states pets are not allowed on flights to or from Hawaii from the mainland, though pets are accepted on flights between the Hawaiian Islands.

What documentation does a service dog need on Southwest?

A completed U.S. Department of Transportation Service Animal Air Transportation Form, dated on or after the ticket purchase date, is required at check-in. Southwest states that a vest, harness, ID card, or registration certificate cannot substitute for this form.

How many pets can I bring on one Southwest flight?

Each ticketed customer may bring one pet carrier, which can hold up to two small cats or dogs of the same species, and Southwest limits each flight to six total pet carriers on a first-come, first-served basis.