In-cabin pet fees by airline (2026)
In-cabin pet fees range from $35 within Hawaii on Hawaiian Airlines to $250 each way — the ceiling, charged by 1 US carriers. Every fee below comes from the airline's official policy, next to its carrier size limit — because the fee only matters if your carrier actually fits.
| Airline | In-cabin pet fee | Max carrier (L×W×H) | How it's booked |
|---|---|---|---|
| Hawaiian Airlines | $35 within Hawaii; $125 between Hawaii and North America | 17 × 11 × 9.5 in | Call Hawaiian Reservations (1-800-367-5320) at least 48 hours ahead. |
| Mokulele Airlines | $35 per animal under 16 lbs; 16 lbs or more is charged at the standard fare | not published | Call (808) 495-4188 at least 48 hours ahead; without notice there may be a $100 fee or denied boarding. |
| Southern Airways Express | $35 service fee per animal, per direction (up to two small animals with a combined weight of 25 lbs. or less in the same carrier) | not published | Call the Southern Airways Express Call Center at (800) 329-0485 at least 48 hours before your flight or when making your initial reservation — there is a limit to the number of pets per flight. |
| Air Europa | $36–181 depending on the route; $36 domestic Spain and Balearic Islands, $52 Canary Islands, Europe, Africa and Intra-America, $155 long haul to Miami, Santo Domingo, New York, Punta Cana or San José, $181 other long haul (EUR 35, 50, 150, 175). Non-refundable; some countries add tax | 15.7 × 11.8 × 11.8 in | — |
| Cape Air | $49 for transportation of a pet carrier or kennel containing up to two small pets from the same household (waived for up to two bona fide service animals from the same household) | 17 × 12.5 × 8.5 in | Advance notification is recommended — call Cape Air reservations at 800-227-3247; notification is not a guarantee of space. |
| Air Canada | CA/US $50–60 one-way (within Canada & Canada/US); $100–120 international | 17 × 16 × 8 in | Add in advance (space is limited); must see an agent at check-in, 30 min before recommended check-in. |
| Air Transat | $50 within Canada or to the USA · $100 to Europe, Africa, or South destinations (Caribbean, Mexico, Peru, etc.) — per pet, per flight segment, paid up to 24h before departure | 17 × 9.5 × 10 in | Reserve at least 24 hours before departure — pets without a reservation are not accepted at the airport; arrive with the pet and a completed Pet Information Form at least 2 hours before departure. |
| Allegiant Air | $50 per segment, per carrier | 18 × 12 × 11 in | Check in with an Allegiant agent at the ticket or gate counter at least 1 hour before departure. |
| Porter Airlines | $50–$57.50 per direction ($50.00 CAD/USD plus applicable taxes) · non-refundable | 21.5 × 15.5 × 10.5 in | Reserve when booking or call the Porter Call Centre at 1-888-619-8622 — space-available, minimum 24 hours' notice. |
| WestJet | $50–$59 within Canada and the U.S.; $100–$118 outside Canada and the U.S. (pet kennel fee, as published on WestJet's fees page; applies each direction) | 16 × 10 × 8.5 in | Request space for your pet as soon as your booking is complete and at least 48 hours before departure — WestJet limits pets per flight and cannot guarantee space otherwise. |
| SAS Scandinavian Airlines | $60–159 per pet container, one way; $60 domestic, $80 Scandinavia, Europe and Middle East, $105 Asia, Canada and US, $159 China (EUR 55, 75, 99, 149). Service dogs travel free in the cabin | 15.7 × 9.8 × 9.1 in | Request when you book, or up to 24 hours before departure at the latest under My trips; if you cannot book within 24 hours of buying your ticket, contact SAS Customer Service. |
| Eurowings | From 60 € / £53 / 56 CHF / $69 per flight, depending on route (no additional charge for assistance dogs) | 21.7 × 15.7 × 9.1 in | Add the pet in the "Travellers" booking step or by calling the Call Centre; it can also be added to an existing booking. |
| Condor | Per person and per leg, by destination: $75.00 within Germany up to $115.00 on long-haul flights including Canada and the USA (Condor flights only; partner-airline fees apply on their segments) | 21.6 × 15.7 × 9 in | Book pet transportation in the cabin up to 24 hours before departure. |
| Sun Country Airlines | $75 each way (booked in advance) or $100 walk-up | 17 × 12 × 9 in | Call Sun Country Reservations to add your pet. |
| Lufthansa | $80–165 depending on the route; $80–100 domestic, $95–115 within Europe, $110–130 Levant and Egypt, $120–140 intercontinental short haul, $135–155 medium haul, $145–165 long haul (EUR 65–145 by the same routes). Charged once per flight direction, and again for return flights and stopovers over 24 hours; pay in My bookings, through the service center, at check-in or at the Lufthansa counter (assistance dogs travel free) | 21.7 × 15.7 × 9.1 in | Register the animal on Lufthansa's pet page ("Register animal now"); Lufthansa checks availability and books it no later than 72 hours before departure. |
| Alaska Airlines | $100 each way per kennel/carrier ($35 if traveling wholly within the State of Hawai'i), subject to space | 17 × 11 × 9.5 in | Reserve before the day of travel: cabin pet space is limited and first-come, first-served. |
| Alaska Horizon (Horizon Air) | $100 each way per kennel/carrier ($35 if traveling wholly within the State of Hawai'i), subject to space | 17 × 11 × 9.5 in | Reserve before the day of travel: cabin pet space is limited and first-come, first-served. |
| EL AL Israel Airlines | US$100 Europe and Middle East; US$150 North America and Far East; 50 NIS Eilat — for an animal up to 9 kg with its cage travelling as baggage | 13 × 8 × 7 in | Subject to approval by the EL AL service center and cabin availability — contact the service center as early as possible, as designated pet seats must be assigned (LITE ticket holders are charged for the designated seat). |
| JSX | $100 per one way | 17 × 13 × 11 in | Indicate your pet when booking online, or call Customer Support at (800) 435-9579 before flying — a completed JSX Pet Acceptance Form is required. |
| Saudia | $100 USD for cabin transport on domestic and international flights (excluding USA & Canada, which have their own regional fees) | 21 × 16 × 13 in | Tell Saudia when you book. |
| Royal Air Maroc | Domestic flights 290 MAD; Europe/Maghreb 640 MAD / €70; Africa, North America, Brazil, China and Middle East 1,150 MAD / €120 / US$120 / C$120. Service dogs travel free. | 21.7 × 15.7 × 7.9 in | Tell Royal Air Maroc you wish to travel with your pet at the time of booking, more than 48 hours in advance. |
| Avelo Airlines | $125 pet fare each way per pet carrier | 17 × 9 × 13 in | Reserve in advance by purchasing the pet add-on when booking, or call the Customer Solutions Center at (346) 616-9500 — first-come, first-served until capacity is reached. |
| Southwest Airlines | $125 each way (US mainland); $35 between the Hawaiian Islands | 18 × 10.5 × 10 in | Space is limited — Southwest recommends reserving in advance by calling; the Pet Fare is paid at the Southwest ticket counter and is refunded if you cancel. |
| Finnair | Within Europe: €60 or 7,800 Avios (7 days or more before departure) / €65 or 8,500 Avios (6 days or less). Intercontinental: €120/$130 or 15,800 Avios (7 days or more) / €130/$140 or 17,100 Avios (6 days or less). Charged per pet carrier, per journey | 21.7 × 15.7 × 7.9 in | Buy online in the Travel extras step when booking, or add later via Manage booking — must be done before check-in opens; Business Class short-haul, Premium Economy long-haul and Jettime-operated flights require contacting customer service. |
| Frontier Airlines | $149 per pet, each way (non-refundable) | 18 × 14 × 11 in | Add "Cabin Pet" in the Passenger Info step when booking, or later via Manage Trip → "Add Pet in Cabin". |
| American Airlines | $150 per kennel each way (carry-on, within/between US, Canada, Mexico, Central America & Caribbean) | 18 × 11 × 11 in | Find your trip on aa. |
| American Eagle (regional, incl. Republic Airways) | $150 per kennel, each way | 18 × 11 × 11 in | Add the pet to your booking in advance by calling American Airlines Reservations; the fee is paid at the airport or a travel center by credit card or paper voucher. |
| Contour Airlines | $150 each way (effective July 1, 2026; pets previously travelled at no charge) | 24 × 16 × 10 in | Reservations for your pet must be made in advance over the phone with Customer Experience — pets cannot be booked online. |
| Delta Air Lines | $150 each way (within US/Canada/Puerto Rico/USVI); $200 international | 18 × 11 × 11 in | Call Delta Reservations to add your pet before travel. |
| JetBlue | $150 each way (or TrueBlue points) | 17 × 12.5 × 8.5 in | Add in the Extras section at jetblue. |
| Korean Air | US$150 short-haul, US$225 medium-haul or US$300 long-haul one-way on international flights, and KRW 30,000 on domestic flights in Korea (pet plus carrier up to 32 kg; the same fare in the cabin or the hold); charged in the currency of the departure country, paid separately from baggage by card, miles or SKYPETS points, and recalculated on the weight measured at check-in | 17.5 × 12.5 × 7.5 in | After purchasing your ticket, request the Traveling with Pets service at least 48 hours before an international flight (24 hours before a domestic flight), then select a seat designated for pet travel. |
| United Airlines | $150 each way | 18 × 11 × 11 in | Choose “Travel with a pet” for the traveler on united. |
| LATAM Airlines | $250 long haul (between South America and Europe or North America); $200 regional (between South American countries, or to Central America or Cancún); within one country: $45 Ecuador or Peru, CLP 50,000 Chile, COP 60,000 Colombia, BR$200 Brazil. A stopover where you can leave the airport is charged per leg, and some countries add tax | 15.7 × 11 × 9.8 in | — |
| Aegean Airlines | €39 domestic / €72 international (direct or connecting) for a cat or dog in the cabin up to 8 kg with its container, charged per container regardless of the number of pets and per route; +€8 per passenger service fee if booked via the call centre after the ticket has been issued; refundable | 15.7 × 9.8 × 9.8 in | Book at the 'Extras' step on aegeanair. |
| Aer Lingus | — | not published | Pets travel only in the aircraft hold, booked through a pet agent at IAG Cargo; pets brought to an Aer Lingus check-in desk are not accepted. |
| Aeroméxico | — | not published | Reserve in advance; a health certificate and vaccination card are required. |
| Air France | In the cabin, one-way per carrier: EUR 70 within Metropolitan France; EUR 125 within the Caribbean, within Europe/Europe–North Africa, and Metropolitan France–Cayenne/Fort-de-France/Pointe-à-Pitre/Saint-Denis Réunion; EUR/USD/CAD 200 US-Canada–Europe (and Cayenne, Fort-de-France, Pointe-à-Pitre, Saint-Denis Réunion, Nouméa, Tel-Aviv); EUR/USD/CAD 250 US-Canada–rest of world; EUR 200 other flights. Adding a pet less than 24 h before departure adds a surcharge (50% within Metropolitan France and the Caribbean, 25% international) | 18.1 × 11 × 9.4 in | Add the Pet Travel Option under "My Booking" (or when you book) at least 48 hours before departure, the deadline Air France gives for the cabin. |
| Air New Zealand | — | not published | Pets travel as checked-in baggage, not in the cabin. |
| airBaltic | €70 per crate per direction on airBaltic flights; if your layover is over 24h, the fee applies per flight; non-refundable | 21.7 × 15.7 × 9.1 in | Contact airBaltic BEFORE booking your ticket: pet places per flight are limited and must be confirmed in advance; €70 per carrier per direction; no seats in the first row or emergency exit. |
| ANA (All Nippon Airways) | — | not published | Pets travel in the bulk cargo room as checked baggage. |
| Asiana Airlines | KRW 30,000 domestic; USD 140 Korea to Japan, China, Taiwan, Hong Kong or Mongolia; USD 210 other Asia, Guam and Saipan; USD 290 U.S., Europe and Oceania, per segment at the lowest weight tier | 17.7 × 12.6 × 8.2 in | — |
| Austrian Airlines | EUR 65–125 depending on the route, plus a ticket service fee that varies by departure location; EUR 65 within Austria, EUR 80 Europe incl. Morocco and Armenia, EUR 105 Jordan, Egypt, Iran, Iraq, Israel, EUR 115 Chicago, Maldives, Miami, Canada, New York, Washington D.C., EUR 125 Thailand, South Africa, Los Angeles, Mauritius, China, Japan | 21.7 × 15.7 × 9.1 in | Add the pet during flight booking, or register it afterwards via My bookings, by telephone, via the contact form, or through your travel agency. |
| Avianca | Varies by route (taxes included): from COP 80.000 within Colombia; from USD 45 within Ecuador; from USD 45 within Guatemala; from CAD 235 from Canada; from USD 200 between South America; from USD 170 between North America, Central America and the Caribbean; from USD 220 to Europe; from EUR 220 / GBP 220 from Europe. High season (January, July, November, December) fares may increase by up to USD 20. Not available on flights to the United Kingdom. | 22 × 14 × 10 in | Request up to 48 hours before departure via avianca. |
| Azul Linhas Aéreas | R$ 300–320 per segment on domestic and South America flights (Azul's page shows both figures); to the USA and Europe R$ 1,400 in Economy or R$ 1,650 in Business per segment (or USD 250 / USD 300) | 16.9 × 12.4 × 7.8 in | — |
| Breeze Airways | Additional charge posted at booking on the Breeze website (the Contract of Carriage doesn't publish the amount) — check when you book | 17 × 8 × 13 in | Domestic flights only — pets are not permitted on international flights. |
| British Airways | — | not published | No cabin option. |
| Brussels Airlines | An additional fee applies per flight, purchased when booking; Brussels Airlines publishes no single figure and carriage is subject to availability | 21.7 × 15.7 × 9.1 in | Book in advance online via "My booking" or through the Brussels Airlines Service Centre — subject to availability. |
| Cathay Pacific | — | not published | Pets travel in the hold via Cathay Cargo's Cathay Live Animal service. |
| China Airlines | — | not published | Pets travel in the cargo hold as checked baggage. |
| Copa Airlines | — | 18 × 11 × 11 in | Reserve the pet's slot up to 48 hours before the flight through Copa Sales Offices or the Call Center; a per-flight fee applies. |
| Croatia Airlines | €32 + 25% VAT domestic; €50 international within Europe; €70 international outside Europe; €10 more on international flights bought on the day of departure in Croatia or Bosnia and Herzegovina | not published | Reserve in advance through Croatia Airlines offices or the Contact Center; pet transport is always charged. |
| Discover Airlines | Subject to a fee that depends on the route (Discover publishes no single figure; its Service Center quotes the price) | 21.7 × 15.7 × 9.1 in | Advance registration and confirmation are required. |
| easyJet | — | not published | — |
| Edelweiss | — | 21.7 × 15.7 × 9.1 in | — |
| Emirates | — | not published | No cabin option for pets. |
| Etihad Airways | USD 399 per flight in Economy; in Business the price is an extra seat + USD 399. Falcons fly free in the cabin as part of your baggage allowance. | 15.7 × 15.7 × 8.7 in | Submit Etihad's online pets booking form with the required travel documents at least seven days before your flight. |
| GOL Linhas Aéreas | Per leg, per pet: Domestic R$ 200,00 or USD 45,00 (booked more than 48 hours before departure) / R$ 250,00 or USD 50,00 (less than 48 hours). South America R$ 1000,00 or USD 200,00 (more than 48h) / R$ 1050,00 or USD 210,00 (less than 48h). Other international destinations R$ 1100,00 or USD 220,00 (more than 48h) / R$ 1250,00 or USD 250,00 (less than 48h). | 16.9 × 12.6 × 9.4 in | Book during ticket purchase or afterwards in the 'Minhas Reservas' / My Trips area of voegol. |
| Iberia | Per segment, online/airport: Spain excl. Canaries EUR40/USD50/GBP35 online, EUR44/USD55/GBP40 airport; Canaries, Europe, North Africa and Israel EUR60/USD75/GBP55 online, EUR66/USD80/GBP60 airport; America, Asia and Qatar EUR180/USD215/GBP160 online, EUR198/USD235/GBP175 airport. Connecting flights: EUR60/EUR80/EUR200 online respectively (EUR66/EUR88/EUR220 airport). Fee is per carrier, not per pet | 17.7 × 13.8 × 9.8 in | Add the pet online at iberia. |
| Icelandair | — | not published | Pets cannot fly in the cabin. |
| ITA Airways | Per single flight route: domestic EUR 73 / USD 85; to-from Europe, Algeria, Tunisia EUR 95 / USD 120; Cairo, Tel Aviv, Amman, Beirut, Tripoli, Jeddah, Riad, Dakar, Accra, Dubai EUR 100 / USD 125; Miami, Boston, Delhi, Malè, New York, Washington, Chicago, Toronto EUR 210 / USD 265; Los Angeles, Houston, Buenos Aires, Rio de Janeiro, Sao Paolo, Tokyo, Bangkok, San Francisco, Mauritius EUR 230 / USD 290 | 21.7 × 15.7 × 9.1 in | Book when purchasing the ticket or via ITA's Information and Customer Service Office; you must also complete the form for transporting dogs/cats as additional baggage in the cabin before departure and submit it in duplicate at check-in. |
| Japan Airlines | — | not published | Pets travel in the bulk cargo room as checked baggage. |
| KLM Royal Dutch Airlines | EUR 70 to EUR 500 per one-way flight, depending on route | 18.1 × 11 × 9.4 in | Reserve via My Trip as soon as possible after booking your flight, and no later than 48 hours before departure. |
| LOT Polish Airlines | — | 17.7 × 11.8 × 7.9 in | Book on lot. |
| Norwegian | 55–75 EUR (online) or 60–85 EUR (airport), per animal, each way | 16.9 × 12.2 × 7.9 in | Book online when booking your flight or by calling the Contact Centre; you can add a pet to an existing booking online using your booking reference and surname, subject to availability. |
| Pegasus Airlines | 750 TRY domestic; 65 EUR international; 900 TRY to or from the TRNC, for an animal in the cabin up to 8 kg | 19.7 × 12.6 × 12.6 in | Call the Pegasus call center right after buying your ticket so the pet is confirmed; no seats in emergency-exit or front rows. |
| Qantas | — | not published | Pets travel in the hold via Qantas Freight — book your pet's flight BEFORE booking your own; for international travel Qantas recommends using a pet travel specialist. |
| Qatar Airways | — | not published | No cabin option for cats/dogs — they are booked as checked baggage or cargo. |
| Ryanair | — | not published | — |
| Singapore Airlines | — | not published | Pets travel as checked baggage, not in the cabin. |
| Swiss International Air Lines | Route-dependent and always charged as excess baggage. In the cabin: USD 80-100 (CHF 75-95) within Switzerland; USD 95-115 (CHF 90-110) Europe; USD 110-130 (CHF 105-125) Levant and North Africa; USD 120-140 (CHF 115-135) short-haul intercontinental; USD 135-155 (CHF 130-150) medium-haul intercontinental; USD 145-165 (CHF 140-160) long-haul intercontinental; USD 250 (CHF 245) to or from Japan | 21.7 × 15.7 × 9.1 in | Tell SWISS well in advance, in "My bookings" or through its Service Center; flights to or from the USA use SWISS's own registration form instead of My bookings. |
| TAP Air Portugal | From 150 EUR / 183 USD / 254 CAD or 30,000 miles on intercontinental flights, from 70 EUR / 86 USD / 119 CAD or 14,000 miles within Europe, Morocco and Tunisia, and from 40 EUR / 51 USD / 70 CAD or 8,000 miles on domestic Portugal flights (TAP's low-season online prices; contact center and airport prices are higher, and prices vary by channel, booking date, travel date and route); non-refundable | 17.7 × 11.8 × 9 in | Add via Manage your Booking if you already hold a ticket, or contact the TAP Contact Center, an airport desk or a travel agency; must be requested at least 24 hours before the flight as specific seats must be assigned. |
| Transavia | €50 per pet per one-way flight on HV flight numbers; €60 to €180 per pet per one-way flight on TO flight numbers | 15.7 × 11.8 × 9.4 in | Cats and dogs must be at least 15 weeks old; the carrier goes under the seat in front, and you may still bring one piece of hand luggage. |
| Turkish Airlines | No flat fare: Turkish Airlines prices each trip in its pet fee calculator, and the pet is not part of your checked baggage allowance | 15.7 × 11.8 × 9.1 in | Add the pet with your reservation code (PNR) on turkishairlines. |
| Virgin Atlantic | — | not published | No cabin option. |
| Viva Aerobus | — | 17.3 × 13.8 × 8.3 in | Add the pet service when you book or well in advance: once a flight's 6 cabin-animal places are taken, Viva can refuse more. |
| Volaris | — | 17.3 × 11.8 × 7.5 in | When booking, at the seat-selection step choose the 'Viaja con tu mascota' option and select 'a bordo' (in cabin) or 'documentada' (checked); can also be added afterwards in 'Mis Viajes'. |
| Vueling | From €50 domestic; from €60 international and Canary Islands | 17.7 × 15.4 × 8.3 in | Select the Fly Light fare in the "Customise your flight" section during booking (applies to all legs); to add a pet to an existing booking or to a single leg, contact the Vueling Customer Service Centre. |
Ranked side by side with under-seat space and weight, as a CSV: the airline pet fee & carrier-size index 2026 →
Fees are the airlines' published in-cabin rates, each read between 2026-08-14 and 2026-11-06 — airlines change fees without notice, so confirm at booking. Sources are cited on each airline page. Which airlines changed their pet rules, and when →
The fee is the easy part — the size limit is what catches people. A carrier that fits one airline may be over the limit on another. Run your airline through the fit matcher →
How much does it cost to fly a cat or a dog in the cabin?
$35–$250 each way in airline fees, across the 30 airlines that publish a plain US-dollar fee; the median fee is $90. A round trip is two fees, so $180 at the median and up to $500 on the priciest carriers. Per-segment airlines charge again at every connection.
Cat or dog makes no difference to the fee. 62 of the 62 airlines that allow cabin pets accept cats, 61 accept dogs. What changes the price is the airline, the route and whether your pet flies in the cabin or the hold.
What else to budget: a carrier that fits your airline's published limit (check yours in the matcher), and on international trips a vet health certificate plus the destination's entry rules. The hold (cargo) is priced separately and is a different decision: in-cabin vs cargo.
Fee traps worth knowing
- Per segment vs each way. Allegiant charges per segment, per carrier — a connection doubles it.
- Walk-up premiums. Sun Country charges $75 booked in advance but $100 at the airport.
- Route restrictions beat fees. Hawaiian Airlines' $35 fee ties for the cheapest we track — but cabin pets aren't allowed at all on its international routes or to/from JFK, BOS, AUS and SLC.
- The carrier is your personal item. On most low-cost carriers the pet carrier replaces your personal item — budget for a paid bag if you need one.
Then pick the carrier: best carriers ranked by airline-fit → · compare limits: all airline policies · start from your carrier: all carriers
Which carrier fits your airline?
Every airline sets its own under-seat size, so the right carrier depends on who you fly. Pick yours for the carriers that clear its published limit: Southwest Airlines · American Airlines · Delta Air Lines · United Airlines · Alaska Airlines · JetBlue · Frontier Airlines · Air Canada · WestJet · all airlines →
Flying over Thanksgiving or Christmas? Read the holiday pet-travel guide →
Carriers that clear the most airlines
Ranked by how many of the 58 airlines with a published cabin limit each one clears at its published size — the same computation behind every fit verdict on this site.
Affiliate link — we may earn a small commission at no extra cost to you. It never changes our specs or which carriers we list.
Sherpa Original Deluxe (Small)Clears 41 of 58 airlines outright · 15 × 10 × 8.5 in · up to ~8 lb
No new copies on Amazon right nowMr. Peanut's Gold Series Mini (Low-Profile)Clears 31 of 58 airlines outright · 17 × 11 × 9 in · up to ~15 lb
See on Amazon →Petmate Soft-Sided Kennel Cab (Medium)Clears 14 of 58 airlines outright · 17 × 10 × 10 in · up to ~10 lb
See on Amazon →Mr. Peanut's Gold Series Standard (Expandable)Clears 12 of 58 airlines outright · 18 × 11 × 10 in · up to ~20 lb
No new copies on Amazon right nowIn stock and fits the same airlines: Mr. Peanut's Gold Series Mini (Low-Profile) on Amazon →Common questions
How much does it cost to bring a cat or dog on a plane?
In the cabin, $35–$250 each way in airline fees across the 30 airlines that publish a US-dollar fee, with a median of $90; a round trip is two fees ($180 at the median). Cats and dogs pay the same fee. Budget separately for a carrier that fits your airline's limit and, internationally, a vet health certificate.
Which airline has the cheapest in-cabin pet fee?
Among the airlines we track, the lowest headline fee is $35, charged by Hawaiian Airlines ($35 within Hawaii; $125 between Hawaii and North America), Mokulele Airlines ($35 per animal under 16 lbs; 16 lbs or more is charged at the standard fare), Southern Airways Express ($35 service fee per animal and per direction) — but check the routes that fee applies to before assuming it covers your flight; the cheapest fee and the widest route coverage are not always the same airline. The highest published US fee is $250 each way, charged by 1 of the carriers in the table below.
Is the pet fee per flight or each way?
Almost always per direction (each way), and on some low-cost carriers per segment - a round trip with a connection can mean four segment fees. Each airline page here states how its fee is charged, from the official policy.
Does paying the pet fee buy my pet a seat?
No. The fee only covers carrying your pet in an approved carrier under the seat in front of you. The carrier usually also counts as your personal item.