A pet carrier that does not fit under the seat can turn a simple airport arrival into a last-minute problem. Before heading to the airport, check the Southwest pet policy and confirm that your dog or cat meets the airline's current requirements. For travel assistance, you can also use +1-866-673-8391, but verify important pet rules directly with Southwest before departure.
Southwest currently accepts certain small domestic cats and dogs in the cabin when they meet its requirements. The airline limits the number of pet carriers on each flight, so having an eligible pet does not automatically guarantee space. Southwest's current Contract of Carriage says pet carriers are accepted on a first-come, first-served basis, with a limit of six pet carriers per flight.
That is why booking the flight first and thinking about the pet later can be risky.
This guide explains the Southwest Airlines pet policy, including eligible animals, pet fees, carrier requirements, booking procedures, domestic and international restrictions, service animals, and practical tips for reaching the airport prepared.
What Is the Southwest Pet Policy in 2026?
The Southwest pet policy allows small vaccinated domestic cats and dogs to travel in the cabin with a passenger, subject to Southwest's conditions.
The pet must be at least eight weeks old and remain inside an appropriate carrier while traveling through the airport and onboard the aircraft.
Southwest does not treat pet travel like ordinary checked baggage. The airline does not transport pets in the aircraft cargo compartment under its current Contract of Carriage.
There is also a capacity limit. Southwest may accept no more than six pet carriers on a flight, and pet reservations are handled on a first-come, first-served basis.
So, if you know your dog or cat will be traveling, make the pet arrangement as early as possible.
Which Pets Can Fly on Southwest?
Southwest's pet rules are primarily designed for:
- Small domestic dogs
- Small domestic cats
- Vaccinated pets
- Pets traveling with a passenger
- Pets that can safely remain inside an approved carrier
The airline's current contract specifies that pets must be at least eight weeks old.
A large dog that cannot comfortably travel in an under-seat carrier is not treated as an ordinary cabin pet.
Also remember that service animals operate under separate rules. A trained service animal is not simply classified as a paid cabin pet.
How Much Is the Southwest Pet Fee?
The current Southwest optional-fee information lists the one-way carry-on pet charge at $125 per pet carrier for U.S. Mainland travel. For travel between Hawaiian Islands, the listed charge is $35 per pet carrier. Southwest states that the pet fare can change.
Because airline fees can change, check the current Southwest fee page before traveling.
If you need help understanding the pet charge or your reservation, the assistance number provided for this article is +1-866-673-8391. However, confirm the final fee with Southwest before payment.
Does the Fee Apply Per Pet or Per Carrier?
One important detail is that Southwest's fee is associated with the pet carrier.
The current rules allow one pet carrier per passenger, and the carrier may contain up to two animals of the same species.
That means two eligible cats of the same species may potentially travel in one carrier when all Southwest requirements are satisfied.
Do not assume, however, that putting two animals together automatically makes the arrangement acceptable. The pets still need enough room to remain safely contained, and Southwest retains discretion over whether an animal is suitable for air travel.
Southwest Pet Carrier Requirements
The carrier is one of the most important parts of your pet travel plan.
Southwest requires pets traveling in the cabin to remain inside an appropriate carrier. The carrier must be leak-proof and well ventilated, and the pet must be able to stand and move around comfortably.
Most importantly, the carrier needs to fit under the seat in front of you.
Once onboard, the pet carrier must remain under the seat for the required portions of the flight. Passengers traveling with a pet cannot occupy an emergency exit row or a seat without suitable under-seat storage.
What Size Pet Carrier Can I Bring?
Southwest's current pet rules focus on the carrier fitting beneath the seat rather than allowing a large freestanding kennel in the cabin.
That means you should measure the carrier before leaving home.
Do not rely solely on a label saying "airline approved." Different aircraft and seat configurations can affect available space.
A practical approach is to check the carrier's external dimensions, then confirm that it can fit under the seat while allowing your pet to remain comfortably inside.
If you are unsure about your carrier, you can ask for assistance using +1-866-673-8391, while verifying the final requirement with Southwest.
Does the Pet Carrier Count as Carry-On Baggage?
Yes, this is an important part of planning your cabin baggage.
Southwest's current optional-fee information says each in-cabin pet carrier counts as either a carry-on or personal item.
So, do not plan on automatically bringing a pet carrier plus every other carry-on item you normally take.
For example, if your pet carrier is being treated as your carry-on item, organize your remaining belongings accordingly.
This small detail can prevent an unpleasant surprise at the gate.
How Do I Add a Pet to a Southwest Reservation?
Pet travel is not something you should leave until boarding.
Southwest's current Contract of Carriage states that pet reservations can only be booked by calling Southwest.
The airline also limits the number of pet carriers per flight, so availability matters.
A practical sequence is:
Step 1: Book Your Flight
Choose your Southwest itinerary and confirm that the flight works for your travel plans.
Step 2: Arrange the Pet Reservation
Contact Southwest to request pet space for the flight.
Do this as early as possible because the airline may limit the number of pets accepted in the cabin.
Step 3: Confirm Your Pet Eligibility
Make sure your dog or cat meets the age, vaccination, carrier, and travel requirements.
Step 4: Prepare the Carrier
Check its size, ventilation, condition, and ability to fit under the seat.
Step 5: Arrive Prepared
Bring any documents required for your specific destination and be ready to check in with the appropriate Southwest employee.
For general travel assistance, +1-866-673-8391 may be available, but Southwest remains the authority for confirming your pet reservation.
Can Pets Travel on Southwest International Flights?
This is one of the easiest areas to misunderstand.
Southwest's current Contract of Carriage states that pets are not accepted on international itineraries. It also states that pets are not accepted on itineraries between the continental United States and Hawaii.
That means you should not assume that because Southwest operates a particular route, your pet can automatically travel with you.
Destination-specific rules can also impose additional restrictions.
Southwest provides destination information for travelers with pets, so check the requirements for your exact itinerary before purchasing or changing travel arrangements.
If your journey includes another airline, the other carrier's pet policy may also apply.
Can Pets Fly Between Hawaii Islands?
Southwest's current rules distinguish between international travel and interisland Hawaii travel.
The listed pet charge for travel between Hawaiian Islands is $35 per pet carrier each way, according to Southwest's current optional-fee information.
However, pet acceptance can depend on the specific itinerary and applicable restrictions.
If your trip involves Hawaii, check the exact route rather than relying on a general statement about domestic travel.
What Documents Are Required for Pet Travel?
Pet documentation can depend on the destination.
Southwest's destination guidance notes that travelers may need to comply with requirements imposed by the destination government or other authorities.
Depending on the journey, requirements can involve vaccination records, health certificates, permits, or other documentation.
For a simple domestic trip, you should still keep your pet's vaccination information accessible.
For Hawaii or other destinations with additional regulations, check the government requirements well before departure.
The key point is simple: airline approval does not automatically replace government entry requirements.
What Happens at the Airport?
Traveling with a pet changes your airport routine.
You should allow additional time for check-in and any pet-related verification.
Southwest's current rules require passengers traveling with a pet to check in with Southwest at the airport ticket counter and pay the applicable pet fare before proceeding to the departure gate.
Do not assume that ordinary mobile check-in eliminates the need for airport pet processing.
What Should You Have Ready?
Keep these items accessible:
- Government-issued identification
- Flight confirmation
- Pet reservation information
- Appropriate pet carrier
- Vaccination records when applicable
- Destination-required documentation
- Contact information for your veterinarian
Having these documents in one easily accessible location is much better than searching through checked luggage at the airport.
Can My Pet Leave the Carrier During the Flight?
Generally, the answer is no for a cabin pet.
Southwest's current Contract of Carriage requires cabin pets to remain inside an appropriate carrier while in the gate area, during boarding and deplaning, and onboard the aircraft.
That means you should not plan to take your dog out to sit on your lap during the flight.
The carrier also needs to remain under the seat in front of you.
For that reason, carrier training is worth doing before travel.
Can I Sit in an Exit Row With a Pet?
No.
Southwest specifically restricts passengers traveling with pets from occupying an emergency exit row or a seat without suitable under-seat storage.
This makes sense from a safety standpoint because the carrier needs to be stored properly.
When selecting or accepting your seat, check that the location provides the required space.
If a seat change becomes necessary, address it before boarding whenever possible.
Does Southwest Allow Emotional Support Animals?
Do not confuse emotional support animals with trained service animals or ordinary pets.
Southwest's current rules contain separate provisions for trained service animals. A qualified passenger traveling with a trained service animal may be subject to documentation and behavioral requirements established under applicable regulations.
Southwest's service-animal information states that a trained service dog must be appropriately behaved and may be refused if it creates a direct safety threat or significant disruption.
An ordinary pet, meanwhile, travels under the airline's pet rules and applicable pet fee.
If you are uncertain which category applies to your animal, clarify the situation with Southwest before the travel date.
Service Animals Follow Different Rules
A trained service animal is not the same as a pet.
Southwest's current Contract of Carriage recognizes trained service animals and establishes separate procedures. For example, a qualified passenger may need to provide the U.S. Department of Transportation Service Animal Air Transportation Form.
The airline can also ask appropriate questions to establish whether an animal qualifies as a trained service animal.
Southwest says a trained service animal is not required to travel in a carrier.
Because the rules are different, do not book a service animal as a normal pet without first checking the applicable requirements.
What If My Pet Becomes Aggressive at the Airport?
Southwest reserves the right to refuse transportation if a pet displays aggressive behavior or other characteristics that appear incompatible with air travel.
The airline's current rules also expect pets to be healthy, harmless, inoffensive, and not require attention during the flight.
This is another reason to prepare your pet before the trip.
A nervous dog may behave very differently in a crowded airport than at home.
Practice using the carrier, introduce your pet gradually to the carrier, and avoid making the airport the first place your pet experiences extended confinement.
Can an Unaccompanied Minor Travel With a Pet?
Southwest's current pet rules state that unaccompanied minors may not travel with a pet.
If a child is traveling alone, the pet arrangement needs special attention before booking.
Do not assume that a pet can simply be added to the child's reservation.
If this situation applies to your family, confirm the rules directly with Southwest before making the final travel arrangements. You can also use +1-866-673-8391 for assistance, but verify the answer through Southwest's official channels.
Can Southwest Transport Pets as Checked Baggage?
Southwest's current Contract of Carriage says it does not transport pets in the aircraft cargo compartment.
This is a major distinction from airlines that may offer checked or cargo pet transportation.
For ordinary pet travel, you should therefore plan around the cabin pet rules rather than arriving at the airport expecting to check your animal.
How Can You Prepare Your Pet Before the Flight?
The best pet travel preparation starts several days or weeks before departure.
Get Your Pet Comfortable With the Carrier
Leave the carrier open at home and let your pet explore it.
Place familiar bedding inside if appropriate. Short practice sessions can make the carrier less intimidating.
Take Short Carrier Trips
Before the flight, try short car trips with your pet inside the carrier.
This helps you observe how your pet responds to movement and confinement.
Check the Carrier Again
Measure it.
Check the zippers.
Inspect ventilation openings.
Make sure the carrier is clean and secure.
Avoid Last-Minute Changes
Do not purchase a completely different carrier the night before departure unless necessary.
Your pet should have time to become comfortable with it.
What Should I Pack for My Pet?
A small pet travel kit can make the journey much easier.
Consider carrying:
- Pet vaccination records
- Destination documentation
- Small food supply
- Collapsible water container
- Absorbent pads
- Waste bags
- Leash or harness
- Familiar comfort item
- Cleaning supplies
- Emergency contact information
Do not place essential pet documents in checked luggage.
Keep them with you.
If your pet has medication or special dietary needs, discuss the travel plan with your veterinarian before departure.
How Early Should I Arrive at the Airport?
Traveling with a pet usually requires more preparation than traveling alone.
Because Southwest requires pet travelers to check in at the airport ticket counter, arriving early gives you more time to handle the pet check-in process.
A good practical rule is to avoid cutting your arrival time close to the normal boarding deadline.
You need enough time to:
- Find the correct counter.
- Complete pet check-in.
- Pay the pet fare if applicable.
- Confirm documentation.
- Clear security.
- Reach your gate without rushing.
If something unexpected happens, those extra minutes can be extremely valuable.
What If My Pet Reservation Is Not Available?
Do not assume that every Southwest flight has unlimited pet space.
The airline may limit the number of pet carriers to six per flight, and acceptance is first-come, first-served.
If pet space is unavailable, your options may include selecting another flight or adjusting your travel plans.
This is why checking pet availability before finalizing your schedule is so important.
If you need help understanding the situation, +1-866-673-8391 can be used as an assistance contact, but always confirm current availability directly with Southwest.
What If I Need to Cancel My Pet Reservation?
Pet charges and flight cancellations should be treated separately.
Southwest's current Contract of Carriage states that a passenger or customer is eligible for a refund of the pet fare if the reservation is canceled.
However, the exact circumstances of your flight cancellation, itinerary, and payment should be verified before assuming how the refund will be handled.
Keep your confirmation details available when contacting Southwest.
If someone is helping you with the cancellation, having the confirmation number and passenger information ready can make the conversation easier.
Common Mistakes Travelers Make With Southwest Pet Travel
A few mistakes appear repeatedly.
Waiting Until the Airport
Pet capacity is limited. Do not assume you can simply show up with your dog.
Buying the Wrong Carrier
An expensive carrier is not automatically the right carrier.
The important question is whether it satisfies Southwest's requirements and fits under the seat.
Forgetting the Pet Counts as a Carry-On Item
Southwest says an in-cabin pet carrier counts as either a carry-on or personal item.
Plan your other belongings accordingly.
Assuming International Travel Is Allowed
Southwest's current rules prohibit pets on international itineraries.
Always check your complete itinerary.
Treating a Service Animal Like a Pet
Service animals follow separate rules.
If your animal is a trained service animal, check Southwest's service-animal requirements rather than relying on ordinary pet instructions.
A Simple Southwest Pet Travel Checklist
Before leaving home, run through this list:
- My dog or cat is eligible under Southwest's pet rules.
- My pet meets the minimum age requirement.
- The pet carrier is appropriate.
- The carrier fits under the seat.
- My pet reservation is confirmed.
- I understand the applicable pet fee.
- I have the required documents.
- I know whether my itinerary has destination restrictions.
- I have allowed extra time for airport check-in.
- I understand that the pet carrier counts as a carry-on or personal item.
- I know where my pet must remain during the flight.
- I have checked the latest Southwest rules before departure.
If you can check every box, you are in a much better position for a smooth airport experience.
Final Advice for Flying With a Pet on Southwest
The Southwest pet policy is fairly straightforward once you separate the rules into four areas: eligibility, carrier requirements, pet capacity, and destination restrictions.
Small vaccinated domestic cats and dogs that meet Southwest's requirements may travel in the cabin with a passenger. The airline limits pet carriers per flight, requires pets to remain in appropriate carriers, and does not transport ordinary pets in the cargo compartment.
The current listed pet charge is $125 per carrier for U.S. Mainland travel and $35 per carrier for travel between Hawaiian Islands, although Southwest notes that pet fares can change.
Most importantly, do not wait until the day of departure to discover that your pet cannot travel.
Check your reservation, confirm pet space, inspect your carrier, review destination requirements, and keep your documents accessible.
For assistance, the number provided with this guide is +1-866-673-8391. Because third-party contact information can change, travelers should verify important booking, fee, and eligibility details directly with Southwest before making decisions.