Frontier Airlines Pet Policy 2026: $99 Fee, 6 Species Allowed

Frontier charges $99 each way to fly with a pet in the cabin — the lowest fee among major US airlines. Dogs, cats, rabbits, guinea pigs, hamsters, and small household birds are all welcome on domestic flights, giving Frontier the widest species list in the industry.

No cargo option exists. No checked pets. And as of early 2025, no pets on international flights — service dogs only. This guide covers cabin rules, carrier sizes, the booking process, and what actually happens at check-in.

In-Cabin Travel

Frontier allows pets in the cabin on all domestic flights for $99 per direction, non-refundable. You can pay during booking or at the airport counter.

Your carrier goes under the seat in front of you. Frontier accepts both soft-sided and hard-sided carriers:

• Soft-sided: 18" × 14" × 11" (45 cm × 35 cm × 28 cm) — recommended by Frontier
• Hard-sided: 18" × 14" × 8" (45 cm × 35 cm × 20 cm)

The 8-inch height limit on hard carriers is tight — most standard pet carriers exceed it. Use a soft-sided carrier. The extra 3 inches of height makes a real difference.

Frontier has no official weight limit. The carrier must fit under the seat and be large enough for your pet to stand, turn around, and lie down. Carrier dimensions are the real constraint.

One pet per passenger. Your carrier does not count as your personal item — you get the carrier plus one bag (personal item free, carry-on for a fee). Most airlines make the carrier replace your personal item, so this is a genuine perk.

Seat restrictions: No Row 1, no exit rows. If your carrier doesn't fit under a particular seat, Frontier will work with you to reassign.

In-flight rules: Your pet must stay in the carrier the entire flight. Frontier recommends no food or water for your pet within 4 hours of departure and none during the flight. If your pet becomes disruptive, you need to calm them without removing them from the carrier. Frontier advises against sedating pets — the effects of tranquilizers at altitude are unpredictable, and a visibly sedated pet may be refused boarding.

Species

This is where Frontier stands out. Domestic flights accept:

• Dogs and cats (minimum 8 weeks old)
• Rabbits
• Guinea pigs
• Hamsters
• Small household birds (no parrots, macaws, cockatoos, or birds of prey)

Most US airlines only allow dogs and cats. If you're flying with a rabbit or guinea pig, Frontier is one of your only options.

Not allowed: Large birds, rodents (mice, rats, squirrels), beavers, ferrets, reptiles, amphibians, spiders, insects.

Cargo and Checked Pets

Frontier doesn't transport pets in cargo or as checked baggage. If your pet doesn't fit in a cabin carrier, Frontier can't help you.

For large dogs, Alaska Airlines offers cargo at $200 each way.

Service Animals

Frontier accepts trained service dogs only — no emotional support animals (discontinued February 1, 2021), no service animals in training. Psychiatric service dogs are accepted.

Service dogs fly free in all cabins. You need the DOT Service Animal Air Transportation Form — submit it at least 48 hours before departure through Frontier's online portal. If you booked less than 48 hours out, bring the form to the airport.

Domestic: dogs must be over 4 months old. International: 6 months. Max 2 service dogs per passenger.

One thing to know: Frontier's system has a history of not updating passenger records with service animal status. A traveler with approved paperwork was pulled off a plane because the CRO couldn't see the animal in the system — Frontier later admitted the error. Check your passenger record 24 hours before departure to confirm the service animal shows up.

Breed Restrictions

None. Frontier has no breed restrictions — flat-faced breeds (French Bulldogs, Pugs, Boston Terriers, Persian cats) fly under the same cabin rules as every other breed.

Since Frontier doesn't offer cargo, the brachycephalic breed bans that affect other airlines don't apply here.

Required Documents

These are Frontier's rules — separate from what your destination state may need.

Domestic flights: Frontier doesn't ask for a health certificate or vaccination proof. Show up with your pet in an approved carrier and you're set.

The catch: your destination state might have its own rules. Colorado technically requires a health certificate for dogs entering the state. In practice, nobody checks — but it's on you, not Frontier.

Puerto Rico: Health certificate within 30 days of travel, rabies vaccination within 6 months (pets 4+ months old), external parasite treatment within 72 hours before entry, and a microchip or collar with ID tag.

US Virgin Islands: Health certificate, rabies vaccination within 6 months, ID with address and phone recommended.

How to Book a Pet on Frontier

1. Book your flight first on flyfrontier.com or the Frontier app.
2. Add your pet during checkout — select "Cabin Pet" in the Passenger Info section. Already booked? Go to Manage Trip and select "Add Pet in Cabin."
3. Pay the $99 fee during booking or at the airport counter.
4. Check in online — Frontier lets you check in online with a pet on your reservation. Most airlines force counter check-in for pet travelers, so this saves time.
5. Arrive 30 minutes early anyway. Gate agents may inspect your carrier at boarding, and the counter handles any issues with your reservation.
6. At TSA security: Remove your pet from the carrier, carry them through the metal detector, and send the empty carrier through the X-ray. For cats or nervous pets, ask for a private screening — TSA takes you to a small room instead.

Tip

Bring a leash for TSA even if your pet never uses one. You'll carry your pet through the metal detector while the carrier goes on the X-ray belt. Without a leash, a nervous cat or dog can bolt.

Common Mistakes

What Travelers Say

We monitor recent traveler experiences through Reddit, Facebook groups, and other sources. Here's what keeps coming up.

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On check-in and enforcement:

"I've flown in and out of Denver with my 10-lb dog dozens of times. I have never once been asked for anything, ever." — Lisa T., frequent Frontier flyer

"I've flown with Frontier with my pets and had no problem. I paid online for it and was able to check in online. They literally do not care and are so chill." — Karen M., cat owner

"They didn't even ask me for the health certificate, or even look twice at the carrier." — Megan S., California to Colorado

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On carrier size:

"My second flight with my pet, Frontier was so strict about the crate fitting under the seat in front of me. I would recommend a carrier that's soft instead of those hard crates." — Megan S., Frontier regular

"Frontier is known to be very strict on bag sizes, especially because their gate employees are contractors who receive pay bonuses for baggage charges." — Jake R., experienced traveler

"I have a ragdoll cat, about 15 pounds. He couldn't fit in any carrier that met Frontier's dimensions. I ultimately flew Southwest." — Emily P., ragdoll cat owner

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On the overall experience:

"Strangely had better experiences on Frontier than on United." — Karen M., multi-airline comparison

"I've flown with my pet a lot to and from Denver on Frontier. Nobody checks anything. They DO want the pet out of the carrier to go through security. I learned to ask for a private screening to avoid my cat being terrified and trying to escape." — Dan C., Denver regular

Watch Out

Frontier's gate agents are contractors — they're stricter on carrier size than agents at most legacy airlines. A soft-sided carrier that meets the 18" × 14" × 11" limit is your safest bet.

Tips for Flying Frontier with Your Pet

Use a soft-sided carrier — always. The 3-inch height difference between hard-sided (8") and soft-sided (11") is the difference between your pet fitting and not fitting. The Sherpa Original Deluxe Medium is recommended by multiple Frontier travelers for cats up to 18–19 lbs.

Your carrier doesn't replace your personal item. Unlike most airlines, Frontier lets you bring the pet carrier plus one bag. You keep your backpack or purse — but if you want a carry-on (the larger bag), that's an extra fee.

Ask for a private TSA screening with cats. Instead of removing your cat in the middle of the security line, request a private room. TSA takes your carrier through the X-ray while you handle your cat in an enclosed space. Multiple Frontier travelers call this a game changer for anxious cats.

Use WhatsApp for booking issues. Frontier's phone support is limited, but their WhatsApp chat (accessible through flyfrontier.com) handles pet additions, one-way pet bookings on round trips, and other changes.

The hidden costs. The $99 fee is just Frontier's cut. A carrier runs $30–$80 (the Sherpa Deluxe is the most recommended by Frontier travelers). If you're flying to Puerto Rico or the USVI, a vet visit for the health certificate runs $50–$150. Budget the full picture.

International Routes

Frontier no longer accepts pets on international flights — effective early 2025. Only service dogs (with CDC Dog Import Form, microchip, and DOT form) can fly internationally on Frontier.

Before this change, dogs and cats could fly to Mexico and the Dominican Republic. Several third-party sites haven't updated this yet — if you see Mexico or DR listed as pet-friendly on BringFido or similar sites, that information is wrong.

Pets are still allowed on flights to Puerto Rico and the US Virgin Islands (these are domestic, not international), but you'll need destination-specific paperwork — see Required Documents above.

How Frontier Compares

Frontier's $99 fee is the lowest among major US airlines. Delta jumped to $150 in April 2025, and JetBlue matches that. The trade-off: no cargo, no international pet travel, and gate agents who are tighter on carrier size than most airlines. If your pet fits in the carrier, Frontier is a solid budget option. If your pet is borderline on size, Southwest's more relaxed enforcement is the safer bet.

FAQ

Your next step: Add your pet during booking on flyfrontier.com — select "Cabin Pet" in the Passenger Info section. If you've already booked, use Manage Trip to add it.