Flying with a dog or cat is possible on many airlines, but the rules vary enormously between carriers, and even between routes operated by the same airline, so there is no single set of answers that applies everywhere. What follows is the general shape of how pet air travel works — cabin, hold and cargo, crate requirements, and the costs and catches — but you should always confirm the specific policy of your airline and route directly before booking, ideally before you buy a ticket at all.
The three ways a pet can fly
Airlines that carry pets generally offer up to three options, though not every airline offers all three, and some offer none at all.
- In the cabin: small dogs and cats, usually under a low weight limit (often around 8kg including the carrier, though this varies by airline), can travel in an approved soft-sided carrier stowed under the seat in front of you. Cabin space for pets is usually limited to a small number of animals per flight, so book this well in advance.
- In the hold, as checked baggage: larger pets travel in a hard-sided, airline-approved crate in a pressurised and temperature-controlled part of the hold. This is a common option for medium and larger dogs that don't qualify for the cabin.
- As manifest cargo: for larger animals, or when the owner is not travelling on the same flight, pets can be shipped as freight through a cargo booking, generally arranged separately from a passenger ticket and often via a specialist pet relocation agent.
Which of these an airline offers — and under what conditions — differs significantly by carrier. Some airlines do not accept pets in the cabin at all; others restrict hold travel to certain routes or suspend it altogether during hot summer months because of heat risk in the hold. Check your specific airline's current pet policy rather than assuming it matches a previous flight or a different carrier.
Crate and carrier rules
For hold and cargo travel, airlines generally require an IATA-compliant crate: rigid, well-ventilated, large enough for the animal to stand, turn around and lie down naturally, with secure but not padlocked doors (crew may need to access the animal in an emergency). Cabin carriers are usually soft-sided and must fit fully under the seat, which rules out anything but genuinely small pets.
Get the crate sizing right well before travel — airlines will refuse animals in crates that don't meet the size or ventilation standard, and this is not something that can be fixed at the airport. IATA's Live Animals Regulations set out the industry-standard crate specifications that most airlines reference, and are a useful starting point even though your specific airline's rules take precedence.
Documents and health requirements
Flying with a pet doesn't remove any of the border requirements that apply to the destination — microchipping, vaccination and, for many international routes, an EU pet passport or Animal Health Certificate are still required regardless of how the animal travels. See our guide to the EU pet travel scheme for how those requirements work for European travel, and our broader guide to crossing borders with a pet for destinations further afield. Many airlines also require a health certificate from a vet issued shortly before the flight, separate from any border-entry document — check both requirements, as they serve different purposes.
Costs
Pet travel fees vary by airline, cabin class and whether the pet travels in the cabin or the hold, and are charged separately from the human passenger fare. As a general pattern, cabin pet fees tend to be a flat charge per flight, while hold and cargo travel — priced by weight and crate size — can cost considerably more, especially on long-haul routes. Because pricing structures differ so much between airlines, get a specific quote for your route and pet's size rather than relying on a rule of thumb.
Booking and timing
Book your pet's place well before finalising the rest of your itinerary — this matters just as much for onward connections and layovers as it does for the outbound flight itself; the same forward-planning habit applies to booking seat reservations if part of your onward journey continues by train.
Most airlines cap the number of pets allowed per flight, in the cabin in particular, so book your pet's place as early as possible once you have a confirmed flight — ideally at the same time as the ticket, since adding a pet afterwards is not always guaranteed to be possible. Some airlines will not accept pet bookings made purely online and require a phone call or a request through customer service instead.
Long layovers and tight connections both carry extra risk for a travelling pet — a long layover means more time in a crate, while a tight connection risks the pet not making the transfer with the same care as on a direct routing. Direct flights are generally the more comfortable option for the animal wherever a realistic one exists.
When flying isn't the right choice
For elderly pets, animals with health conditions, or brachycephalic breeds facing restrictions, flying may not be advisable at all, and an overland alternative — driving, or rail and ferry where the destination allows — may be kinder and lower-risk, even if it takes longer. Discuss your specific animal's suitability for air travel with your vet, who can advise based on age, breed and health rather than general guidance. If you're weighing up a ferry crossing instead, see our guide to booking ferries for how pet policies generally work on sea crossings.
Insurance and unexpected costs
Standard travel insurance rarely covers a pet directly, so check separately whether you need pet travel insurance, and confirm what your regular travel insurance does and doesn't cover if a flight disruption affects your pet's booking or connection. See our guide to travel insurance for how standard policies are structured, and check with a specialist pet insurer for cover specific to the animal itself.
Frequently asked questions
Can any dog or cat travel in the aircraft cabin?
Only small pets under the airline's specific weight and carrier-size limit, and only in an approved soft carrier that fits under the seat. Limits and rules vary significantly between airlines, so check with your specific carrier before assuming your pet qualifies.
Is it safe for a pet to travel in the hold?
The hold sections used for animals are pressurised and temperature-controlled, and many pets travel this way without incident, but risk is not zero, particularly for brachycephalic breeds, elderly animals, or in extreme heat — which is why some airlines restrict or suspend hold pet travel seasonally or by breed. Discuss your specific pet's suitability with your vet.
Do I need special paperwork beyond what the airline asks for?
Yes — airline requirements (such as a health certificate) are separate from the destination country's border-entry requirements (such as an EU pet passport or Animal Health Certificate). Both must be satisfied, and missing either can prevent your pet from travelling or entering.
Why do some airlines not accept certain dog breeds at all?
Flat-faced (brachycephalic) breeds are more prone to breathing difficulties under the stress and conditions of hold travel, so a number of airlines restrict or refuse them for hold travel, and policies vary considerably by carrier. Always check breed-specific policy directly with your airline.
Sources and further reading:
- Crate and carrier standards: IATA Live Animals Regulations.
- EU and UK pet border requirements: European Commission and UK government (gov.uk).
- Always confirm current pet policy, fees and breed restrictions directly with your airline before booking.