The Most Plus-Sized Friendly Airline

Every traveler has different needs, and some require additional space when flying. For travelers who must buy more than one seat to have enough space, though, the costs of air travel can quickly climb.

Most U.S. carriers have policies and procedures for travelers who cannot fit comfortably with the armrests down, requiring them to purchase an additional seat. This rule can double the cost of a flight.

Last year, as the Federal Aviation Administration (FAA) collected comments as part of its consideration of airline seat size, droves of passengers mentioned the challenges posed to customers who want an extra seat for personal comfort.

One traveler, Alison Wiesner, wrote, “Seat size needs to be more inclusive, we aren’t sardines, we are people who spent money to travel,” noting she’s been “bruised by tight seats,” and as a result hasn’t flown in years.

Meanwhile, tens of thousands of people have signed a petition in recent months, which calls on the FAA to establish stricter regulations for airlines with respect to both travelers of a certain size and others needing special accommodations.

Among other provisions, the petition, created by plus-size travel influencer Jaelynn Chaney, specifically calls on the agency to require airlines to provide passengers with size-accessible seating or an extra seat at no cost.

“The ultimate goal is to provide a positive flying experience for all,” the petition says.

Southwest Airlines may be the major U.S. airline with the most generous policies when it comes to larger flyers.

The airline says that customers who encroach “upon any part of the neighboring seat(s) may proactively purchase the needed number of seats prior to travel.”

Purchasing multiple seats ahead of time helps the airline plan for the number of customers, Southwest says.

However, the Southwest policy for customers who require a second seat will allow those passengers to request a refund for the extra seat after traveling.

Customers who don’t purchase an extra seat ahead of time are encouraged to speak with a gate agent to arrange for the extra space, which Southwest will grant at no charge, the carrier says.

That goes even for full flights.

Each airline has procedures for how to book a second seat for yourself. Here’s how it works on Southwest.

As you select your flight, you’ll want to book your tickets for “2 adults.”

Then, proceed through the “itinerary” and “pricing” pages.

After that, you’ll want to pay close attention as you fill out the “Who’s Flying” fields. For “Passenger one,” put your name as you usually would (first and last name, or first, middle and last name).

For passenger two, put your name again, but for middle name, mark XS (as in, extra seat).

If you purchased an additional seat, you can request a refund of the additional seat purchase after the conclusion of your trip by sending an email to Southwest.com/feedback or calling 800-435-9792.

Each airline sets its own policy for seating customers who require an extra seat. On most — but not all — other major U.S. carriers, you will likely have to pay for a second seat.

Alaska Airlines customer-of-size policy offers possible refunds to passengers.

While you’re required to purchase an additional seat if you cannot fit comfortably with the armrests down, you’ll be eligible for a refund on the second seat, assuming the flight had an open seat available in each direction.

Like most of its fellow “legacy” carriers, the American Airlines customer of size policy requires customers who need extra space to purchase additional seats. On its special assistance webpage, the carrier encourages customers “to address all seating needs when booking.”

If you don’t select seats in advance (basic economy tickets, for instance, don’t allow complimentary seat selection,) the airline encourages flyers to speak with a gate agent to find out if two adjacent seats are available.

If no two seats are adjacent on your current flight, “you can buy seats on a different flight at the same price as your original seats,” American’s policy says.

American Airlines does not offer a refund on second seat purchases.

The Delta customer-of-size policy notes that passengers who require a seatbelt extender do not automatically have to purchase an additional seat.

However, the Atlanta-based carrier notes that if the traveler impedes upon another passenger’s space, they may be asked to move to another location or take a later flight with more available seating.

Delta says it “recommends” passengers purchase an additional seat to avoid such a situation. Keep in mind this does require a main cabin ticket since basic economy doesn’t include complimentary seat selection.

Delta does not offer a refund on second seat purchases.

Frontier’s policy for customers of size says that customers who cannot lower both armrests or who compromise “any portion” of adjacent seat or aisle space should book two seats prior to travel.

Fellow budget airline Spirit likewise requires an extra seat for guests of size who “encroach” on an adjacent seat area or cannot sit in their seat with the armrest lowered.

Spirit charges for seat selection.

United’s policy reads: “If you can’t sit safely and comfortably in a single seat in United economy, you’ll have to purchase an additional seat for each leg of your itinerary.”

The airline notes passengers who require such can buy the second seat at the same price as long as both seats are purchased simultaneously.

United further says it will not board those passengers when they do not purchase an additional seat in economy or a larger, premium seat.

In airline officials cannot find adjacent seats on a flight, passengers will be required to purchase seats on the next flight with space. In this case, United will waive change fees or penalties and provide meals and hotel accommodations if the a delay stretches overnight and you are outside your home city, state or country.

Though Southwest is the biggest U.S. airline to outright offer extra seat refunds to travelers of size, most other airlines at least lay out their policies so you can be prepared for what to expect when flying.

If you’re running into mounting costs between extra seats and seat fees, a call to your airline’s reservations line certainly can’t hurt — perhaps they can find a way to hold adjacent seats for you even if it’s not outlined in their policy or your fare rules.

Meanwhile, as Congress mulls the next FAA reauthorization bill, it’s worth watching whether we might see new regulations related to extra seat policies for travelers needing a bit more space.