How To Choose The Best Airline‑Approved In‑Cabin Pet Carrier

Flying internationally with a cat or small dog starts with choosing the right in‑cabin pet carriers and airline, not just booking a ticket. The pet carrier you use on moving day affects your pet’s stress, safety, and comfort, and can determine whether they are allowed to travel in the cabin with you or must go in the aircraft hold instead.

Why In‑Cabin Pet Carriers Matter When You Move Abroad

Cargo or checked‑baggage transport is still used every day, but it adds layers of uncertainty that many relocating pet owners want to avoid if they possibly can. Pets in the hold are handled by ground crews, exposed to temperature swings during loading, and separated from you during delays and diversions, which is a lot to ask of an animal already coping with an international move. In‑cabin carriers, by contrast, let your pet stay in a climate‑controlled environment at your feet, away from heavy luggage and loud cargo equipment, with you watching for signs of overheating, anxiety, or motion sickness on long‑haul routes.

Because of that, this guide focuses specifically on small cats and small dogs that are eligible to travel in the cabin under the seat in front of you, not medium or large breeds that must use checked or cargo options. The typical in‑cabin limit is around 8–10 kg (about 17–22 lb) including the carrier on many international and Canadian airlines, which means a lot of popular small breeds and most cats can qualify if you plan carefully. The goal here is to help Americans relocating overseas choose an airline‑approved in‑cabin carrier that actually fits real airline rules while keeping their pet as calm and comfortable as possible on what is probably the longest trip of that animal’s life.

What “Airline‑Approved In‑Cabin Pet Carrier” Really Means

When airlines talk about “airline‑approved” pet carriers, they are not talking about a single global certification sticker you can rely on. Instead, each carrier has its own set of rules for pets in cabin, pets as checked baggage, and pets shipped as cargo, and a carrier is “approved” only if it fits the rules for the specific option you are booking on the specific route you are flying. For a typical American moving abroad, that usually means making sure a soft‑sided in‑cabin carrier fits under the seat on every leg of a multi‑flight itinerary while still giving your pet enough space to stand up, turn around, and lie down comfortably.

Airlines generally group pet travel into three buckets that matter for planning an international move. In‑cabin travel is for small cats and dogs that stay with you in the passenger cabin in a carrier that counts as your carry‑on and must fit entirely under the seat in front of you. Checked‑baggage pet travel uses a hard‑sided crate that goes in the hold on the same flight as you, while cargo travel usually runs through a separate cargo system and is often the only option for larger dogs or pets on certain routes and aircraft types. When airlines talk about a carrier being suitable “for cabin” versus “for cargo,” they are really pointing to different size, construction, and ventilation standards that match those three categories.

Basic Airline Rules for Pets in Cabin

Although every airline publishes its own pet policy, the basics for in‑cabin travel are surprisingly consistent in 2025–2026. Small cats and dogs are typically allowed in the cabin if the combined weight of the pet and carrier stays under the airline’s limit, which for many international and North American airlines now sits around 8–10 kg, and the carrier can slide fully under the seat in front of you. Carriers must be well‑ventilated, secure, and leak‑resistant so that a nervous pet does not escape in the aisle or soil the cabin, which is why airlines and pet‑travel specialists generally recommend soft‑sided, flexible carriers for in‑cabin use rather than rigid plastic crates.

Most major airlines also require that your pet stay inside the closed carrier for the entire time you are in the terminal boarding area, during boarding and deplaning, and for the full duration of the flight. Delta, for example, specifies that the pet must remain inside a soft‑sided ventilated kennel under the seat in front of you, and that the carrier counts against your standard carry‑on allowance. Air Canada similarly limits in‑cabin travel to one small cat or dog per passenger, with a combined pet‑plus‑carrier weight cap of about 22 lb (10 kg), and requires that the carrier be stowed under the seat and treated as part of your carry‑on allowance. In practice, that means you cannot plan on having your cat on your lap for take‑off or landing, and you must be comfortable managing the whole trip with one pet in a small, secure, soft‑sided carrier at your feet.

IATA Guidelines and Why They Matter (Even If Airlines Don’t “Approve” Brands)

Behind most airline pet policies sit broader aviation safety and animal‑welfare standards, including the IATA Live Animals Regulations and, for European operators, regulations such as EU 965/2012 and related guidance around pets in cabins up to specific weight limits. These frameworks do not hand out brand‑level “approvals” for in‑cabin carriers, but they do lay out the safety principles airlines must follow: pets must be transported in containers that prevent escape, allow the animal to stand and turn naturally, protect them from injury, and can be secured so they do not become hazards during turbulence.

In Europe, for example, regulators historically limited pets in cabin to a maximum of 8 kg including the carrier, and some national aviation authorities have begun testing slightly higher limits (up to 10 kg) as long as safety and evacuation rules are still met. IATA’s guidance also emphasizes ventilation, secure doors and zippers, absorbent flooring, and the need to avoid overcrowding animals in a single container, which is why airlines tend to insist on one or two small animals per carrier and clear weight caps even when you are using a soft‑sided bag under the seat. For someone relocating abroad, paying attention to these underlying standards helps you choose a carrier that not only fits this year’s airline size chart but is also likely to remain compliant as policies evolve in 2025–2026 and beyond.

Standard In‑Cabin Carrier Dimensions and Weight Limits (With Table)

If you’re trying to choose one carrier that will work across multiple flights, it helps to know that most in‑cabin rules fall into the same general ballpark. On U.S. and Canadian airlines, under‑seat carrier dimensions usually land somewhere around 16–18 inches long, 10–12 inches wide, and 8–11 inches high, with the crucial requirement that the bag can slide fully under the seat in front of you on your specific aircraft type. A lot of airlines do not publish a strict weight cap for in‑cabin pets, but when they do, the combined pet‑plus‑carrier weight commonly falls between about 17 and 22 pounds (8–10 kg), which lines up with what you’ll see on many international and Canadian carriers.

Where things get more complicated is when you mix U.S. carriers that focus on “must fit under the seat” with international airlines that are much more precise. European and some transatlantic airlines often specify exact dimensions and an 8 kg (about 17.6 lb) maximum, including the carrier, and they are more likely to actually weigh and measure at check‑in. That means a bag that squeaks by on a domestic U.S. route could be too tall or too heavy on the long‑haul leg that actually takes you abroad, so it’s smart to pick a soft‑sided carrier that can flex slightly in height and keep your pet’s body weight a couple of pounds below the posted limit.

If your dog is too large for any standard airline-approved carrier—think 50+ pounds, or breeds like Golden Retrievers, German Shepherds, or Labradors—traditional commercial airlines will force you into cargo. Period. But a growing number of families moving abroad refuse to put their dogs in the hold, and for good reason: cargo travel carries real risks, especially for brachycephalic breeds.

Your alternative? Semi-private and charter pet flights. Services like JSX (dogs up to 79 lbs), Bark Air, K9 Jets, and RetrievAir allow large and giant breeds to fly in-cabin with you—no carrier required, your dog sits at your feet or on the seat. Yes, it’s expensive (tickets range from $750 to $12,000 depending on the service and route), but for many immigrating families, keeping their large dog safe and stress-free is worth the cost.

If cargo isn’t an option for your big dog, read our complete guide on US Airlines That Allow Large Dogs in Cabin (Not Cargo) to compare services, pricing, and routes for semi-private pet travel.

Typical Under‑Seat Carrier Sizes on U.S. and Canadian Airlines

On big U.S. brands, you’ll notice a pattern once you start comparing the numbers. Delta and United list 18 x 11 x 11 inches as a common reference size, American and Alaska are in that same neighborhood, and Southwest allows slightly wider bags but with a similar maximum height. In practice, these measurements are really proxies for the footprint under the seat, which can differ between aircraft, so airlines still tell you to choose a carrier that can “fit comfortably under the seat in front of you” rather than guaranteeing a single standard.

Canadian airlines aren’t quite identical, but they’re moving in the same direction. Air Canada, for example, has tightened its rules in recent updates so that only flexible, soft‑sided carriers are allowed in the cabin, and passenger reports and policy summaries put the under‑seat maximum at roughly 17 inches long, 16 inches wide, and about 8 inches high for soft carriers. Air Transat publishes an even more conservative set of measurements—around 17 x 9.5 x 10 inches—for in‑cabin carriers and explicitly requires that your pet stay in that carrier under the seat for the whole flight. When you average those ranges, a realistic working target for a “move‑abroad” carrier that works on most North American flights is something like 17 x 11 x 10 inches, with enough flexibility in the sides and top to compress a bit if a particular seat is tighter.

Example In‑Cabin Pet Limits by Popular Airlines

Below is a simplified snapshot of current in‑cabin limits for airlines that come up often in U.S.‑to‑abroad moves. Always double‑check your specific flight, but this table gives you a sense of the real‑world constraints you’re planning around.

Always verify dimensions, weight limits, and pet fees directly on your airline’s website for your specific route and aircraft within a few weeks of departure; the numbers in this guide are reference ranges, not guarantees.

For a move abroad with a small pet, it’s usually safest to choose a carrier that respects the strictest set of rules you’re likely to encounter—often something that fits KLM/Turkish‑style dimensions and keeps your combined weight under 8 kg, even if your first leg is on a more generous U.S. airline.

How to Measure Your Cat or Dog for an In‑Cabin Carrier

Getting the dimensions right starts with your pet, not the bag. Airlines care that your cat or dog can stand naturally, turn around, and lie down without being crammed into a tight space, and the only way to guarantee that is to measure your animal and then work outward to a carrier size that also fits under‑seat rules. If you’re moving abroad, it’s worth doing this carefully once and writing the numbers down so you can cross‑check multiple airlines and carriers without guessing every time you see a new size chart.

Step‑by‑Step: Measuring Your Pet for Airline Travel

Start with weight, because that immediately tells you which airlines and routes are realistic. Weigh your cat or dog on a home scale, then remember that most soft‑sided carriers add roughly 1–2 kg (2–4 lb), which eats into those 8–10 kg in‑cabin limits faster than people expect. If an airline says the maximum is 8 kg including the bag, you usually need your pet alone to be closer to 6–7 kg to leave room for the carrier and a lightweight mat or pad.

Next, measure length. Have your pet stand naturally and measure from the chest (roughly the base of the neck) to the base of the tail, then add about 4 inches (10 cm) so they can stretch out without being pressed against both ends of the bag. For height, measure from the floor up to the top of the shoulders, or slightly above if your pet’s head sits higher than the shoulder line when standing, then add a couple of inches so they can sit without their ears scraping the top of the carrier. Finally, measure width across the widest point of the chest or shoulders and aim for a carrier that’s roughly twice that width plus a few extra centimeters so they can curl comfortably rather than being flattened against the sides. Once you have those three numbers—weight, length plus margin, and height plus margin—you can start shopping for a soft‑sided carrier that meets those internal dimensions while still sliding under the tightest seat you expect on your route.

Choosing the Right Size Carrier for Long‑Haul Flights

For a short hop, people sometimes get away with a carrier that just barely meets the rules. On a long‑haul move with layovers, that strategy backfires quickly. You want something that threads the needle between “small enough to fit KLM or Turkish‑style under‑seat dimensions” and “big enough that your pet isn’t wedged in for 8–12 hours.” In practice, that often means picking the largest soft‑sided carrier that is still within the strictest airline’s published external measurements and then paying close attention to how much of those dimensions are actual usable interior space versus decorative structure.

Soft‑sided carriers help here because their tops can flex down slightly in flight while the base stays within the length and width footprint. A bag that is technically a centimeter taller than the stated maximum often still passes if it compresses easily under the seat, whereas a rigid box will not. If your move involves mixed fleets—say, a narrow‑body domestic connector and a wide‑body long‑haul jet—it’s smart to test‑pack the carrier with your pet at home for a couple of hours to see whether they can shift positions and settle or whether they seem restless and cramped. That dry run tells you more about comfort on a relocation day than any marketing photo ever will.

Special Considerations for Older Pets and Brachycephalic Breeds

Older animals and short‑nosed breeds have less margin for error, so it’s worth being conservative with both size and ventilation. Brachycephalic cats and dogs can struggle more with breathing and temperature regulation, which makes good airflow and the ability to change position in the carrier more important than squeezing every last centimeter out of the width restriction. For seniors with arthritis or stiffness, a slightly longer carrier and a thick but lightweight pad can make it easier to lie comfortably without joints pressing into a hard base for the entire journey.

In all of these cases, a pre‑trip conversation with your vet is non‑negotiable, especially if you’re facing multiple flights or a big time‑zone jump. Vets who work with international travelers can help you balance sedation risks, schedule feeding and watering around flight times, and choose a carrier style that works with your pet’s specific health profile rather than just their measurements on paper. If your vet is worried about breathing issues, you may be better off prioritizing a carrier with mesh on three or four sides and extra headroom, even if that means targeting airlines with slightly more generous under‑seat dimensions or adjusting your route so your pet can travel at cooler times of day.

Airline‑Specific Rules for Pets in Cabin on Popular Relocation Routes

Once you know your pet can travel in cabin, the next step is matching that “theoretically eligible” animal with the very specific rules of the airlines you’re likely to fly when you leave the U.S. for Canada, Europe, or beyond. Each carrier has its own mix of size limits, weight caps, fees, and route‑level restrictions, and those details can make or break an otherwise perfect relocation itinerary. The good news is that most of the big players follow recognizable patterns, so you can usually narrow your options to a few realistic choices once you understand how they treat in‑cabin pets.

NOTE About Service Dogs: If your dog is a trained service animal, different rules apply. Service dogs aren’t subject to carrier size limits, pet fees, or breed restrictions on most airlines—but you’ll need proper documentation and advance notification. See our complete guide on How to Fly With a Service Dog for ADA requirements, airline verification forms, and what documentation you need for international travel.

Air Canada and WestJet In‑Cabin Pet Carrier Rules

For moves that route through Canada, Air Canada and WestJet are often at the top of the list, and both have tightened their in‑cabin policies in recent years. Air Canada requires soft‑sided carriers for pets in the cabin. The maximum carrier dimensions vary by aircraft; in practice, under‑seat space is usually in the ~17–21″ long, 10–16″ wide, and 8–11″ high range, but you must check your specific flight’s aircraft and seat map. The combined weight of your pet and carrier needs to stay under about 22 pounds (10 kg), and your animal must remain in the closed carrier under the seat for the entire flight; the carrier counts as part of your normal carry‑on allowance, not an extra item.

WestJet specifies a maximum in‑cabin carrier size of 16″ × 8.5″ × 10″ (41 × 21.5 × 25.4 cm) and requires a soft‑sided, leak‑proof, well‑ventilated carrier that fits under the seat. WestJet does not prominently publish a single numeric weight cap for in‑cabin pets; your pet must be able to stand up, turn around, and lie down comfortably inside that size. Like Air Canada, WestJet treats the carrier as your carry‑on, limits you to one pet in cabin per passenger, and restricts pets from certain seats and routes, so you can’t assume every flight in their network will accept your animal just because the website says “pets allowed.”

Delta, United, and Other Major U.S. Airlines

On the U.S. side, Delta, United, and their peers are often the first leg of a move abroad, even if a European or Canadian carrier handles the long‑haul segment. Delta continues to allow small cats and dogs in cabin on many routes, as long as they fit in a ventilated carrier that goes under the seat in front of you, and it charges a separate pet fee for each flight segment—currently around 150 USD each way on U.S./Canada routes and about 200 USD each way on most international flights as of 2026. You can’t add a pet to your ticket online; you have to call Delta Reservations, and there are limits on how many pets are allowed per cabin, so you need to book early if your move is tied to a specific date.

United’s 2026 policy also allows small cats and dogs to travel in cabin on many domestic and international routes, with the carrier sliding under the seat and staying closed for the entire flight. United uses reference dimensions in the 18 x 11 x 11‑inch range for soft‑sided carriers and charges a pet‑in‑cabin fee of about 150 USD each way, payable at the airport. There are some notable quirks: only cats and dogs are allowed, certain premium cabins and exit rows are off‑limits, and in some cases you can bring two pets if you purchase two adjacent seats and use separate carriers. Other U.S. carriers like American and Alaska have broadly similar rules—small pets only, under‑seat carriers, per‑segment fees, and bans on in‑cabin pets to countries like the U.K. or Australia where local regulations don’t allow animals in the cabin on arrival. These restrictions are driven by destination‑country biosecurity rules, not just airline policy, so even if the airline allows pets in cabin on other routes, they must route pets as cargo to these countries.

KLM, Turkish Airlines and Other Transatlantic Carriers

When you cross the Atlantic or head toward the Middle East, in‑cabin rules tend to get stricter. KLM, a popular choice for U.S.‑to‑Europe relocations, allows one small dog or cat in the cabin for each passenger in Economy and within‑Europe Business, but only if the combined pet and carrier weigh no more than 8 kg (about 17.6 lb) and the carrier fits under the seat with maximum dimensions of 46 x 28 x 24 cm. Those numbers aren’t suggestions: KLM is known for actually weighing the carrier at check‑in and checking the size, and they will deny boarding or require a switch to hold or cargo if your pet doesn’t meet the in‑cabin criteria and you haven’t arranged another option in advance.

Turkish Airlines follows essentially the same pattern. It allows cats and dogs in cabin only if the total weight of the animal plus carrier does not exceed 8 kg and the carrier measures no more than 40 x 30 x 23 cm. Fees vary by route and weight band, but the consistent themes are a firm 8 kg ceiling, a requirement that the carrier fit fully under the seat, and a rule that the pet stay inside the closed carrier for the entire flight. Other transatlantic and European airlines adopt similar 8 kg, tight‑dimension policies, which means that if your move involves a mix of U.S. and European carriers, you should plan around the strictest carrier’s numbers rather than the most forgiving.

Policies also change more often than most people realize, especially around seat layouts, accepted carrier types, and breed or route restrictions, so whatever combination of airlines you choose, it’s worth reconfirming the in‑cabin pet rules on the airline’s own site within a few weeks of departure and again a few days before you fly.

Best In‑Cabin Pet Carriers for International Flights (Cats & Small Dogs)

When you are planning a one‑way, long‑haul move, your carrier choice matters more than it would for a quick weekend trip. You are asking your cat or small dog to spend hours in a confined space, often across multiple flights, so the bag has to satisfy airline rules and keep your animal genuinely comfortable from boarding to baggage claim.

Features to Look For in an Airline‑Approved Carrier

• Type and Size: Soft‑sided, under‑seat carrier that fits U.S. airline “under‑seat” rules and stricter European 8 kg limits.
• Flexibility: Soft top and sides that can compress to fit different aircraft spaces.
• Structure: Firm, nonsagging base so your pet stays level and comfortable.
• Ventilation: Mesh panels on at least three sides for airflow—especially important for flat‑faced breeds or warm routes.
• Hardware Strength: Durable, lockable zippers that resist pawing or pressure.
• Security: Built‑in interior leash clip so you can open the top safely for pets or hydration.
• Cleanliness: Waterproof or water‑resistant base and a removable, washable pad.
• Convenience: Luggage‑handle sleeve for easier transport through airports.
• Access Points: Both front‑ and top‑loading openings; top‑loading reduces stress when handling a reluctant pet.

Budget-Friendly Soft-Sided Carriers (Under $25)

Henkelion Cat Carrier – Best Overall Value

• Rating: 4.6 stars (51,907 reviews) – Overall Pick
• Price: $22.48
• Dimensions: 17″L x 11″W x 11″H
• Weight Capacity: Up to 15 lbs
• Key Features: Marketed as designed to conform to under‑seat dimensions used by many airlines (always check your specific flight), collapsible, 3-side mesh ventilation, adjustable shoulder strap, luggage strap compatible, side pocket
• Why Recommended: Exceptional reviews, best-seller status, extremely popular (2K+ bought in past month), customers praise quality and comfort
• Amazon Link: https://amzn.to/3ZI1nrq

Mid-Range Soft-Sided Carriers ($25-$40)

Amazon Basics Soft-Sided Mesh Carrier

• Rating: 4.4 stars (29,157 reviews) – Amazon’s Choice
• Price: $30.62
• Dimensions: 20″L x 12″W x 12″H (also available in 17″L x 11″W x 11″H for $23.09)
• Weight Capacity: Up to 22 lbs
• Key Features: Conforms to under-seat dimensions of most airlines, removable/washable fleece pad, mesh ventilation, adjustable shoulder strap
• Why Recommended: Top-reviewed for sturdiness, 400+ bought in past month, trusted Amazon Basics quality
• Amazon Link: https://amzn.to/4aE5OIO

Premium Hard-Sided Carriers ($100+)

SportPet Airline Compliant Medium Travel Kennel

** This kennel is designed for pets traveling in the hold or as checked baggage and is far too large for in‑cabin use. Use it only on routes and airlines that accept pets as checked baggage or cargo and verify that it meets your airline’s IATA‑style crate requirements before travel. **

• Rating: 4.5 stars (6,102 reviews)
• Price: $127.00
• Dimensions: 26.5″L x 20″W x 18.5″H
• Weight Capacity: Dogs up to 23″L & 15″H
• Key Features: Durable plastic construction, removable wheels, 2 food bowls included, collapsible design, Sized and constructed to meet typical IATA‑style cargo crate requirements for many airlines when used in the hold (always verify your airline’s current cargo crate rules)
• Why Recommended: Best for larger pets, hard-sided durability, wheels for easy transport, 50+ bought in past month
• Amazon Link: https://amzn.to/4at19cw

Airline-Specific Recommendations

For Most US Airlines (American, Delta, United, Southwest):

• The Henkelion and Amazon Basics carriers both fit standard under-seat dimensions (typically 18″L x 11″W x 11″H max)
• Both are soft-sided which allows slight compression for tight fits

For Alaska Airlines:

• The Henkelion carrier specifically works
• Alaska Airlines publishes relatively low height limits for in‑cabin carriers on some aircraft (often around 8.5–10 inches). A flexible soft‑sided bag like the Henkelion can compress to fit, but always compare the carrier’s dimensions with the current Alaska pet policy for your exact route and aircraft.

For Larger Pets or Cargo Hold Travel:

• SportPet hard-sided kennel meets IATA requirements for cargo hold transport

Recommended In‑Cabin Carriers for Cats and Small Dogs

For international flights, your best bet is a soft‑sided, airline‑tested carrier that can flex to fit under varying seat heights while keeping your pet secure and calm. Standouts like the (very expensive) Sleepypod Air remain top choices in 2024–2026 for their compressible ends, sturdy structure, and crash‑tested design—ideal for both flight and car segments.

Budget‑minded travelers often look to (the slightly less expensive) Mr. Peanut’s Gold Series carriers, which are built around the under‑seat dimensions used by Delta, United, and Alaska and usually include top and front entry points plus roll‑down privacy flaps for nervous cats.

For small dogs, classics like the (much more affordable) Sherpa Original Deluxe keep their shape with flexible wire frames that squeeze down to fit tighter aircraft models, while lightweight SturdiBag‑style carriers maximize usable interior length without eating up your weight allowance—useful for pets right up against that 8 kg (17 lb) limit.

Whatever brand you choose, cross‑check listed measurements and test‑pack your pet ahead of time; manufacturer “airline approved” labels often overpromise, especially on long‑haul routes or non‑U.S. carriers.

Packing and Training Tips for Stress-Free In-Cabin Pet Travel

Moving abroad with a pet isn’t like a weekend vacation—you’re asking your dog or cat to spend hours in a confined carrier, possibly across multiple flights, while their entire world changes around them. The difference between a traumatic journey and a manageable one often comes down to preparation. Start training early, pack smart, and plan your route with your pet’s comfort in mind, not just the cheapest fare.

Getting Your Pet Used to the Carrier Before You Fly

If your pet’s first experience with their travel carrier is the morning of your international flight, you’ve already lost. Cats and dogs need weeks—ideally a month or more—to build positive associations with what will become their safe space at 35,000 feet.

The training process mirrors standard crate training but deserves extra attention for long-haul moves. Leave the carrier out in a common area with the door open and toss in a familiar blanket or old t-shirt that smells like you. Let your pet investigate on their own timeline. When they venture inside, reward them with treats and calm praise—don’t get overly excited, which can startle them back out.

Gradually increase the duration. Close the door for a few seconds, then a minute, then five. Practice lifting the carrier gently off the ground while your pet is inside, since being elevated can be alarming. Work up to carrying them around the house, then simulate a car ride to the grocery store and back. For an eight-hour transatlantic flight, your pet should be comfortable spending at least that long in the carrier overnight before departure.

Cats often resist carriers because they associate them solely with vet visits. Break that pattern by making the carrier part of daily life—feed meals inside it, or place it near a sunny window so it becomes a cozy nap spot. Dogs may need reassurance that the carrier isn’t a punishment. Keep sessions positive, end on a high note, and never force your pet inside, which only deepens their fear.

Two weeks is the bare minimum for carrier acclimation, but don’t expect miracles. If you’re on a tight timeline, focus on the essentials: your pet should tolerate being zipped in for the flight duration, and they should remain calm when you lift and move the carrier.

What to Put in (and On) the Carrier for a Long Move

Airline rules are strict: no food or water bowls that could spill, no bulky toys that crowd your pet, and nothing that compromises ventilation. That doesn’t mean your pet travels empty-handed. Smart packing makes the difference between a soggy disaster and a bearable flight.

Start with a high-quality absorbent pad lining the bottom of the carrier. Even well-trained pets may have accidents during a 10-hour journey, and you won’t have access mid-flight to change anything. Disposable pee pads work, but washable crate liners with waterproof backing offer better odor control. Some travelers layer a thin, familiar-smelling blanket on top—just enough for comfort without restricting airflow.

Skip the water bowl. Instead, attach a collapsible silicone dish to the inside of the carrier door if your airline allows it, or plan to offer water during layovers using a portable dish you carry separately. Hydration matters, but a spilled bowl creates a miserable environment for your pet and raises eyebrows from flight attendants.

Calming aids are a gray area. Airlines prohibit sedation because it can cause respiratory issues at altitude, but natural options may help. Consult your vet about pheromone sprays (like Feliway for cats or Adaptil for dogs) that you can apply to the carrier fabric an hour before departure. Some owners give a single dose of vet-approved calming supplements or a treat containing a mild antihistamine like Benadryl—but this is a conversation to have with your vet weeks in advance, not a last-minute experiment.

One small, soft toy can provide comfort, but leave the squeaky plush giraffe at home. You want something your pet can nestle against without it blocking airflow or becoming a choking hazard if they chew out of stress. A well-worn stuffed animal that smells like home often works better than a brand-new one.

On the outside of the carrier, attach a luggage tag with your contact information and your destination address. If you’re immigrating, include both your old and new phone numbers—international SIM swaps can leave you unreachable. Some travelers also clip a laminated card with feeding instructions and emergency vet contacts to the carrier handle, though this is more relevant for cargo travel.

Finally, keep a small supply kit in your personal item: extra absorbent pads, disposable gloves, pet-safe wipes, waste bags, and a hand towel. If your pet has an accident during boarding or you need to clean the carrier between flights, you’ll be prepared without having to dig through checked luggage.

Managing Layovers and Multi-Flight Itineraries With Pets in Cabin

Direct flights aren’t always an option when you’re moving from, say, Portland to Amsterdam or Toronto to Berlin. Layovers add logistical challenges, but with smart planning they’re manageable—and sometimes they give your pet a much-needed break.

Bathroom breaks are the top concern. Most healthy cats and dogs can hold it for six to eight hours, but that’s pushing the limit on back-to-back long flights. Many major airports now have pet relief areas post-security—look for them on airport maps or the airport’s website before you fly. Denver, Dallas-Fort Worth, San Francisco, and most large European hubs have dedicated spaces with artificial grass or gravel and waste stations.

Getting to those relief areas with an in-cabin pet isn’t always straightforward. Your pet must stay in the carrier while in the terminal, but at the relief area you can open it and leash-walk your dog or let your cat stretch on a harness. Some travelers report success using disposable pee pads inside a family restroom stall during tight layovers—not ideal, but a pragmatic backup when the relief area is on the far side of a sprawling terminal.

Timing is everything. When you’re immigrating, avoid itineraries with connections shorter than two hours. That’s barely enough time to deplane, clear customs (if applicable), navigate to your next gate, and give your pet a bathroom break. Aim for three hours minimum on international connections. Yes, it extends your total travel time, but a stressed, soiled pet creates a miserable experience for everyone—and risks denied boarding if an agent decides your pet is too distressed to fly.

Choose routes carefully. Some airlines and airports are more pet-friendly than others. KLM, for example, enforces carrier size limits strictly and expects your pet to remain quiet and contained. Lufthansa and Air Canada have similar reputations. On the flip side, some travelers report that smaller regional carriers are more flexible—but that’s not a guarantee. When booking, call the airline directly and ask about their layover procedures for in-cabin pets. Can you exit and re-enter security? Will you need to retrieve your pet at customs? These details matter.

If your itinerary includes a layover in a country where you’re not staying, check that country’s pet import rules. Some nations require pets to remain in the transit area and won’t allow bathroom breaks outside security. Others may demand additional documentation even for a two-hour stopover. The USDA’s Pet Travel website and your destination country’s agriculture ministry website are essential reading.

Keep your pet calm between flights. Once you’re at your connection gate, find a quiet corner away from foot traffic. Sit on the floor next to the carrier and speak softly to your pet. Offer water if they’ll drink it. Resist the urge to open the carrier fully “just to check”—that can lead to an escape attempt in a crowded terminal. If your vet approved a calming aid, a layover is a reasonable time to offer it, but follow dosing instructions carefully.

And one last reality check: if you’re flying from North America to Europe with a connection in Iceland or the UK, understand that some airports simply don’t have great pet facilities. Your dog may need to hold it. Your cat may protest loudly. It’s uncomfortable, but it’s survivable—and far better than the alternative of sending them as cargo.

Common Problems With In-Cabin Pet Carriers (and How to Avoid Them)

Even with perfect preparation, in-cabin pet travel throws curveballs. Gate agents enforce rules inconsistently. Carriers that “should” fit don’t. Your pet decides now is the time to vocalize their feelings about enclosed spaces. Here’s what actually goes wrong—and how to avoid becoming a viral airport meltdown story.

“How Strict Are Airlines About Carrier Size?”

The honest answer: it depends on the airline, the route, the gate agent’s mood, and whether the flight is oversold.

European carriers—especially KLM, Lufthansa, and British Airways—have earned reputations for rigorous enforcement. KLM’s own pet policy sets an 8 kg cap and a 46 × 28 × 24 cm carrier limit, and they are known for measuring at the airport. Travelers routinely report being turned away when carriers exceed those dimensions. They’re not being cruel; it’s about safety and ensuring carriers actually fit under Economy seats, which have less space than North American aircraft.

North American carriers show more variation. Air Canada and WestJet have been known to enforce size and insist that pets can “stand up, turn around, and lie down naturally” inside the carrier—a subjective standard that’s led to boarding denials even when the carrier met published dimensions. United, Delta, and American generally allow carriers up to 18″ x 11″ x 11″, but anecdotal reports suggest enforcement is stricter on full flights or when agents spot a carrier that looks obviously oversized.

Budget carriers like Spirit, Frontier, and Ryanair are wildly inconsistent. They should be strict because they monetize everything, but enforcement often comes down to individual agents—some wave through bulging soft-sided carriers, others pull out tape measures.

Real-world advice: Measure your loaded carrier (with your pet inside and sitting upright) before you leave home. Use the airline’s exact published dimensions, not “close enough.” Soft-sided carriers can compress slightly, but don’t count on a gate agent giving you the benefit of the doubt. If your carrier is borderline, arrive early and check in with an agent before security—getting turned away at the gate with no backup plan is infinitely worse than being rerouted during check-in.

Some travelers keep a backup collapsible carrier in their checked luggage, just in case. It sounds paranoid until you read the stories of passengers who had to buy a new carrier at the airport or miss their flight entirely.

What Happens if Your Carrier Is Too Big or Your Pet Is Too Heavy?

This is where vacation pet travel and immigration pet travel diverge. If you’re denied boarding on a weekend trip, you rebook and go home. If you’re denied while immigrating, you may have already shipped your household goods, canceled your lease, and have no return address.

When a gate agent decides your carrier doesn’t comply, you have three options—all bad:

1. Check your pet as cargo. Most airlines won’t accept last-minute cargo bookings. Cargo requires advance reservations, specific kennel types (hard-sided, IATA-approved), health certificates with different timing, and acclimation paperwork. Even if the airline agrees, your pet won’t be in the climate-controlled cabin—they’ll be in the hold, which some airlines ban during temperature extremes. Checking a pet as cargo on the spot is rarely feasible.
2. Buy a new carrier at the airport. A few large airports have pet supply shops post-security, but don’t count on it. You’d need a compliant carrier in stock, in the right size, that your pet tolerates—and you’d still need to re-train them on the spot. This is a Hail Mary, not a plan.
3. Rebook your flight. If the airline refuses boarding, you’re often on the hook for a new ticket. A WestJet passenger was denied boarding over a carrier dispute, forced to buy a new carrier and pay out-of-pocket for rebooking before the airline later reimbursed her as an “exception.” Reimbursement isn’t guaranteed—airline contracts of carriage typically state that passengers are responsible for meeting pet travel requirements.

Weight limits add another layer. Most airlines cap in-cabin pets at 15-20 lbs combined (pet + carrier). If your dog has gained weight since you booked, or your carrier is heavier than expected, you could be over the limit. Some agents weigh carriers at check-in; others eyeball it. There’s no consistency.

Prevention is your only real option. Weigh your pet and carrier together at home on a luggage scale. If you’re within 2 lbs of the limit, consider a lighter carrier. If your pet is borderline, call the airline a week before departure and ask to speak with someone in their pet travel department—confirm your specific situation is acceptable. Get names and reference numbers. It won’t guarantee smooth sailing, but it gives you documentation if a gate agent disputes you.

And if you’re moving abroad, build in a buffer day at your departure city if possible. Book a refundable hotel near the airport so that if something goes catastrophically wrong, you have 24 hours to regroup rather than scrambling in the terminal with all your worldly possessions.

Multiple Pets, Backpacks, and Lap Time: What’s Actually Allowed

The rules around how you carry your pet, where the carrier goes, and what else you can bring are maddeningly inconsistent across airlines—and poorly explained on most websites.

Can two pets share one carrier? Sometimes. USDA and IATA rules permit two puppies or kittens aged 8 weeks to 6 months, same species, under 20 lbs combined, if they fit comfortably in one carrier. Delta, United, and Air Canada explicitly allow this and charge for one pet. But the airline can refuse if they judge the carrier too crowded or the pets incompatible. And crucially, this exception applies only to very young animals—your two adult cats don’t qualify, even if they’re small.

Trying to sneak two adult pets in one carrier is a fast track to denied boarding and possible bans. Don’t do it.

What about backpack-style carriers? They’re popular because they free up your hands and look less conspicuous than a traditional carrier. Airlines generally allow them if they meet size requirements and fit fully under the seat in front of you. The catch: many backpack carriers are taller than they are wide, which can exceed height limits even if the volume is technically compliant. Measure carefully.

Does your pet carrier count as your personal item or carry-on? This trips up almost everyone. The answer depends on your ticket class:

• Most full-fare economy and above: Your pet carrier is in addition to your standard carry-on and personal item allowance. You can bring a roller bag, a backpack, and your pet.
• Basic Economy (especially on certain routes): Your pet carrier may replace your carry-on, leaving you with only the carrier and a personal item. Air Canada explicitly states this for Basic fares with no carry-on allowance.

Read your specific airline’s policy carefully—buried in the pet travel section, not the general baggage rules. And if you’re flying internationally with a Basic Economy equivalent, call ahead. Showing up with a pet, a roller bag, and a backpack could mean gate-checking something at the last minute.

Can you take your pet out during the flight? Absolutely not. Airlines universally require pets to remain inside the carrier, door closed, stowed under the seat for taxi, takeoff, landing, and turbulence. Some flight attendants turn a blind eye if you unzip the top slightly to pet your animal once you’re at cruising altitude, but this is technically against policy. Opening the carrier fully is prohibited—escaped pets in a pressurized cabin are a safety hazard.

Your pet can’t sit on your lap. They can’t ride in the seat next to you even if you bought that seat. They live under the seat in front of you for the duration. That’s the deal.

One more quirk: Some airlines restrict in-cabin pets from Business Class or premium economy because the under-seat space is smaller or configured differently. KLM doesn’t allow in-cabin pets in Economy Comfort or Business. Check your specific cabin when booking—upgrading your seat could mean downgrading your pet to cargo, which defeats the entire purpose.

Moving Abroad With Pets: What Comes After Choosing the Carrier

So you’ve got your carrier sorted. Your dog or cat can actually fit in it, it meets the airline’s published dimensions, and you’re reasonably confident it’ll pass the gate agent’s inspection. Good—that’s one major hurdle cleared.

But if you think the carrier is the hard part of moving abroad with a pet, I have bad news.

The carrier gets your pet on the plane. Import regulations determine whether they’re allowed off the plane at your destination. And those regulations? They’re a mess of country-specific rules, arbitrary timelines, and paperwork that needs to be completed in exactly the right order or you’re starting over.

Not sure where you’re moving yet? Our guide to Moving Abroad With Pets: The Easiest and Hardest Countries to Relocate To ranks destinations by difficulty—so you know whether you’re facing a simple vet visit or a six-month paperwork marathon.

Import Rules Aren’t Just “Get a Health Certificate”

Every country wants proof your pet is microchipped, vaccinated for rabies, and healthy. That’s table stakes. Where it gets complicated is everything beyond that baseline.

The EU won’t accept your pet until 180 days after a rabies titer blood test proves the vaccine worked. Australia and New Zealand require advance import permits that take weeks to process, then stick your pet in government quarantine for at least 10 days even if you did everything perfectly. Hawaii—yes, the U.S. state—treats arriving pets like international imports and can quarantine them for up to 120 days if a single piece of paperwork is wrong.

Some countries ban entire dog breeds. Others demand that your vet administer tapeworm treatment in a specific 24-120 hour window before departure and document it on the health certificate. Miss the window by an hour? Customs can refuse entry.

Your Flight Route Matters More Than You Think

Not every airline flies pets in-cabin to every destination. British Airways doesn’t allow in-cabin pets at all—your dog goes cargo or doesn’t go. Some routes force connections through airports with terrible (or nonexistent) pet relief areas, which matters when your layover is three hours and your dog really needs to pee.

And if you’re planning to move in July or January, seasonal temperature restrictions might eliminate half your flight options. Airlines ground pet travel during extreme heat and cold, even in-cabin.

The Paperwork Timeline Will Sneak Up on You

Here’s the thing most people miss: you can’t just call your vet two weeks before departure and knock out a health certificate. If your destination requires rabies titer testing—and most desirable expat countries do—you need to start six months in advance because of mandatory waiting periods.

Health certificates expire fast, too. Most countries require them to be issued within 10 days of travel, and some demand additional USDA endorsement that eats up 2-3 business days. Thread that needle incorrectly and you’re rebooking your entire move.

What to Do Next

You’ve handled the carrier—now tackle the rest:

• Check whether your destination country allows your pet’s breed and what their specific import requirements look like. The rules for moving a dog to Portugal are completely different from moving one to Japan.
• Book your flight and reserve your pet’s in-cabin slot. Airlines cap how many pets fly per flight, and popular routes fill up. Don’t assume there’s space.
• Start training your pet to tolerate the carrier now, not the night before you leave. Two weeks minimum, a month is better.
• Line up your vet appointments and understand the timing. Some treatments have to happen months in advance. Others have narrow windows right before travel.

The carrier is just one piece of international pet relocation. For the complete step-by-step process—from choosing your destination and navigating import rules to booking flights and preparing your pet—read our master guide: How to Move Abroad With Pets.

Frequently Asked Questions About Airline Pet Carriers

Official Resources & Airline Pet Travel Policies

Planning international pet travel requires accurate, up-to-date information from official sources. Use these verified resources to research airline policies, understand import regulations, and ensure your pet meets all requirements before departure.

Major U.S. Airline Pet Policies

Each airline enforces its own rules for in-cabin pet travel, including carrier size limits, weight restrictions, breed policies, and booking procedures. Always verify current policies directly with your airline before purchasing tickets.

Alaska Airlines – Pet Policy
Allows pets up to 20 lbs in-cabin; permits two pets per passenger if they fit in one carrier; offers both in-cabin and cargo options on most routes.

American Airlines – Pet Policy
In-cabin pets up to 20 lbs; carrier dimensions 19″ x 13″ x 9″; $150 fee each way; service animals travel free with documentation.

Delta Air Lines – Traveling With Pets
Strict carrier size enforcement (18″ x 11″ x 11″); pets up to 20 lbs; allows two pets of same species in one carrier if 8 weeks to 6 months old.

United Airlines – Pet Policy
In-cabin limit 20 lbs; carrier must fit under seat (17.5″ x 12″ x 7.5″); offers PetSafe cargo program for larger animals on select routes.

Southwest Airlines – Pet Travel
Budget-friendly $95 pet fee; carrier 18.5″ x 8.5″ x 13.5″; domestic flights only; no cargo or checked pet options.

JetBlue – Pet Policy
JetPaws program with welcome kit; pets up to 20 lbs; carrier 17″ x 12.5″ x 8.5″; $125 each way.

Frontier Airlines – Pet Travel
Accepts cats, dogs, and rabbits in-cabin; carrier 18″ x 14″ x 8″; $99 fee; ultra-low-cost option for pet travel.

Hawaiian Airlines – Pet Policy
Strict Hawaii quarantine requirements apply; small pets allowed in-cabin on select routes; check state import rules separately.

International Airline Pet Policies

Air Canada – Pet Travel
Carrier 21.5″ x 15.5″ x 9.5″; pets in-cabin are in addition to carry-on allowance except on Basic Economy; strict enforcement of pet comfort standards.

Lufthansa – Pet Transport
European carrier with Animal Lounge facilities in Frankfurt; strict EU regulations; allows pets in-cabin, checked, or cargo with advanced booking.

KLM Royal Dutch Airlines – Pet Policy
Maximum carrier size 46 cm x 28 cm x 24 cm; pet + carrier must weigh under 8 kg; known for strict size enforcement at gates.

British Airways – Pet Travel
Does NOT allow pets in-cabin except service animals; all pets must travel as cargo through IAG Cargo.

U.S. Government Pet Import & Export Regulations

CDC Dog Import Requirements – CDC Pet Travel
Mandatory CDC Dog Import Form for ALL dogs entering the U.S. (effective August 2024); dogs must be 6+ months old, microchipped, and healthy; additional requirements for dogs from high-risk rabies countries.

USDA APHIS Pet Travel – APHIS.usda.gov Pet Travel
Official guidance for moving pets internationally from the U.S.; covers health certificates, export requirements, and country-specific regulations.

U.S. Department of Transportation Service Animals – DOT Service Animals
Air Carrier Access Act rules; explains documentation requirements for service dogs; clarifies that emotional support animals are NOT recognized as service animals on U.S. flights.

European Union Pet Travel Regulations

EU Pet Passport Information – Europa.eu Pet Travel
Official EU guidance on pet passports for dogs, cats, and ferrets; explains microchip, rabies vaccination, and border crossing requirements within EU member states.

Animal Health Certificates for Non-EU Pets – EU Pet Entry
Requirements for entering EU from outside countries; explains when pet passports vs. health certificates are needed; 10-day validity window for certificates.

Australia & New Zealand Pet Quarantine

Australia Department of Agriculture – Cats and Dogs Import
Comprehensive import requirements; mandatory 10-day quarantine at Melbourne Post Entry Quarantine facility; requires advance import permit (apply 6+ months before travel); rabies titer testing with 180-day waiting period.

New Zealand Ministry for Primary Industries – Importing Pets
Complex regulations for rabies-free status; minimum 10-day quarantine (up to 60 days depending on origin country); advance import permit required; only Auckland and Christchurch entry points.

International Standards & Safety

IATA Live Animal Regulations – IATA Pet Travel
Global standards for transporting live animals by air; covers crate specifications, health documentation, and handling protocols; used by most commercial airlines worldwide.

IPATA (International Pet and Animal Transportation Association) – IPATA.org
Directory of professional pet shippers; resources for complex international moves; members follow strict animal welfare standards.

Additional Resources

Hawaii Department of Agriculture – Pet Quarantine
Unique quarantine requirements for rabies-free Hawaii; explains 5-Day-or-Less program and direct airport release eligibility.

UK Pet Travel Scheme (PETS) – Gov.uk Pet Travel
Post-Brexit requirements for bringing pets to England, Scotland, Wales, and Northern Ireland; no longer accepts EU pet passports from Great Britain.