On January 27, 2026, Southwest Airlines changed three major policies at once: open seating ended, assigned seats went live, and the Customer of Size policy got significantly tighter. The seat policy change has the most direct financial impact on the most travelers, and it’s the one that’s flown under the radar for people who don’t follow airline news closely.

Here’s what changed: passengers who can’t fit within a single seat’s armrests must now purchase a second seat in advance at full price. The refund that used to be nearly automatic after travel is now conditional, and the main condition is that your flight departed with an empty seat somewhere on the plane.

On a sold-out Southwest flight in 2026, you pay for two seats and get nothing back. That’s a major shift from where this policy was a year ago.

What is Southwest’s Customer of Size policy in 2026? Passengers who cannot fit within a single seat’s armrests must purchase a second seat at full price when booking. A refund is available only if the flight departs with at least one empty seat, both seats were in the same fare class, and you request the refund within 90 days of travel. Refunds are not guaranteed.

Quick Verdict: Major U.S. Airline Customer of Size Policies

Airline	Second Seat Required?	Refund Available?	Refund Condition
Southwest (post-Jan 27, 2026)	Yes, purchase at booking	Yes, if conditions met	Flight must depart with open seat; same fare class; within 90 days
Alaska Airlines	Yes, call to book	Yes	All legs must depart with at least one open seat; within 90 days
Delta	Recommended but not strictly enforced	No	N/A
American	Yes	No	No refund policy
United	Yes	No	No refund policy

Bottom line: Southwest used to be the most accommodating domestic option for plus-size travelers. That’s still technically true compared to Delta, American, and United — but the gap between Southwest and Alaska has collapsed. Alaska is now the clearest alternative with any refund path.

What Southwest’s Old Policy Actually Was

To understand why this is significant, you have to know what the prior policy was.

Under the old Customer of Size policy, Southwest allowed passengers needing extra space to request an adjacent seat at the gate, for free, at the time of travel. After the flight, they could request a refund for the fare difference. On most flights, that refund came through, even when planes ran nearly full. The policy worked because Southwest had open seating: plus-size passengers could pre-board, select two adjacent seats in a less congested part of the cabin, and handle the paperwork after the fact.

The National Association to Advance Fat Acceptance (NAAFA) called Southwest’s prior policy the best in the U.S. airline industry — and for practical purposes, it was. No upfront cost, flexible refund, and the ability to choose your own seating arrangement on every flight.

What Changed on January 27, 2026

Three things happened simultaneously:

1. Open seating ended. Southwest moved to assigned seating for all flights departing on or after January 27. This alone made the old Customer of Size process impossible. You can no longer pre-board, pick two adjacent seats, and handle it at the gate.

2. The second-seat purchase is now mandatory and upfront. Passengers who need more space must buy the extra seat when booking, not at the gate. If you arrive at the airport without having done this, you can still purchase the extra seat, but you pay the applicable fare on the day of travel, which is almost always the highest available price on that flight.

3. The refund became conditional. This is the sharpest change. Under the new policy, you’re only eligible for a refund on the second seat if:

• The flight departed with at least one open seat (or a passenger on a space-available pass)
• Both seats were purchased in the same fare class
• You request the refund within 90 days of travel

On a full flight (routine for Southwest on popular leisure routes), you’re eating the cost of that second seat. No refund, no credit, no exception.

One additional detail that catches people: flights with any partner carrier segment are non-refundable for the second seat, period.

The Refund Math in Practice

Southwest’s load factor on leisure routes frequently runs 85–90%+. “Open seat” doesn’t mean the flight wasn’t nearly full. It means at least one seat didn’t have a paying passenger.

In practical terms: some flights will qualify for a refund and some won’t, and you won’t know which until after you’ve traveled. If you’re booking Southwest specifically because you need two seats and you’re planning around getting one of those refunded, you’re making a financial assumption you can’t verify at booking time.

Compare that to what you knew under the old policy: you could nearly always get a refund. The certainty is gone.

Alaska Airlines: The Current Recommended Alternative

Alaska Airlines’ policy has the same basic structure as the new Southwest policy: purchase a second seat in advance, request a refund after travel if conditions are met. But with one meaningful difference: Alaska’s refund trigger requires that all flight legs departed with at least one open seat.

That’s actually a tighter standard on paper than Southwest’s (which only requires the specific flight to have had an open seat). In practice, though, Alaska’s policy has been consistent and clearly documented. Travel agents specializing in plus-size travel have been directing clients to Alaska specifically because the refund process is straightforward and doesn’t involve the January 2026 policy whiplash.

How to book a second seat on Alaska: You can’t do it online. Call Alaska Airlines Reservations at 800-252-7522. The call center ticketing fee is waived for second-seat bookings. Both seats get booked at the same economy fare.

Refund request: Fill out the online form or call 800-654-5669 within 90 days of travel. Provide your name, ticket number, travel date, and flight details.

Alaska’s seat dimensions: economy is approximately 17 inches armrest to armrest. First class is 21 inches. Seatbelt extenders add 25 inches.

Seat Width Tools Worth Bookmarking

If you’re trying to figure out which specific aircraft and seat configuration gives you the most space before booking, a few tools are actually useful:

ExpertFlyer upgraded its seat maps significantly in 2026 through a partnership with aeroLOPA. The new detailed view shows seat width, pitch, recline, and proximity to lavatories for specific aircraft configurations. At $6.99/month for the basic tier, it’s worth a single month if you’re planning a multi-leg trip and want to compare configurations across carriers. The free plan allows one seat alert at a time.

SeatExpert (seatexpert.com) provides detailed airplane seat maps and seating advice at no cost. Useful for a quick reference check on an aircraft type without committing to a subscription.

SeatMaestro has over 900 seat maps from more than 170 airlines. It runs behind on new aircraft configurations, but for standard domestic narrowbodies on Southwest, Alaska, Delta, and American, it covers the relevant data. Free.

For Southwest’s new assigned-seating era specifically: the switch from open seating means seat selection happens at booking. Check the aircraft type on your route before purchasing. A Boeing 737-700 and a 737 MAX 8 have the same stated economy width (17–17.8 inches) but different cabin densities.

What This Means for Trip Planning

The practical impact depends on what you were using Southwest for.

If Southwest was your regular airline because of this policy: The calculus has changed. You’re now paying upfront for a seat you may or may not get refunded, on a carrier that also ended free bags in May 2025. Alaska, which still has two free checked bags on most fares and a comparable second-seat refund policy, is the stronger comparison now for travelers who need both accommodations.

If you’re occasionally flying Southwest on a specific route: Check whether Alaska serves the same route. Alaska’s network covers the West Coast, Pacific Northwest, and a growing number of Midwest and East Coast routes. If Alaska flies your pair, call them.

If Southwest is your only option on a given route: Know the refund terms before you book. Price both seats in the same fare class. Request the refund immediately after travel, not 89 days later. Keep the documentation: your booking confirmation and the receipt for both seats.

If you’re flying with a credit card that has trip protection: American Express Platinum, Chase Sapphire Reserve, and Capital One Venture X all have some form of trip cancellation or interruption coverage. These don’t directly cover a second-seat purchase, but they’re worth reviewing if the overall trip cost is significant. Our airline delay compensation and travel insurance guide has a breakdown of what credit card travel protection actually covers vs. what people assume it covers.

The Baggage Policy Connection

Southwest ended Bags Fly Free in May 2025. Two checked bags used to be included on every Southwest ticket. That was a core part of the value proposition, particularly for travelers who check large bags or adaptive equipment.

For plus-size travelers who were using Southwest specifically because of the combination of the Customer of Size policy and free bags, both benefits are now gone. The airline still has competitive base fares, but the total cost calculation for a two-seat traveler with checked baggage looks materially different in 2026 than it did in 2024.

Alaska includes two free checked bags on most of its fares when booked directly. That’s a relevant factor in the full cost comparison.

What Advocacy Groups Are Saying

NAAFA ran a petition and public campaign before the January 27 changes, gathering over 1,000 signatures and pushing Southwest to keep its accommodations intact. The organization described the change as “devastating” and noted that Southwest and Alaska were the only two U.S. carriers with any reimbursable second-seat option.

Travel agents who specialize in plus-size travel have reported that some clients are actively planning to stop flying Southwest. Whether that becomes a material trend is an open question. Southwest still serves routes and cities where alternatives are limited, and not every traveler has the flexibility to switch carriers on every route.

The broader industry picture is not encouraging: Delta, American, and United have no refund policy for second-seat purchases. Southwest is tighter than it was, but it’s still the second-best domestic option alongside Alaska. That’s a low bar.

Before Your Next Southwest Booking

If you or someone you travel with needs two seats on Southwest, the new workflow is:

1. Book both seats at the same time in the same fare class. Don’t book one now and one later — different fares make you ineligible for the refund.
2. Check the flight’s typical load factor on your route. Full-price leisure routes on weekends run fuller than Tuesday morning departures. If the refund matters financially, choose flights that are less likely to sell out.
3. Request the refund immediately after travel — don’t wait. The 90-day window exists, but there’s no reason to cut it close.
4. Compare Alaska before booking Southwest, if Alaska serves your route. The policies are comparable, Alaska’s is more established, and the combination of two free bags and a functional second-seat refund makes Alaska the cleaner option for travelers who need both.

For broad context on what’s been shifting in domestic airline passenger rights over the past year, the airline delay compensation guide covers the 2025 DOT regulatory rollback and what protections actually survived.

If you’re using AI trip planning tools to compare fares across carriers, the best AI travel planners guide covers which tools are actually useful for itinerary and fare comparison versus which ones hallucinate policies. Airline seat policies are exactly the kind of thing AI planners get wrong — always verify directly with the carrier.

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Policy details current as of March 2026. Southwest Airlines’ Customer of Size policy is documented at southwest.com. Alaska Airlines’ passenger of size policy is at alaskaair.com. NAAFA’s statement on the Southwest policy change is at naafa.org. Airline policies change; verify current terms before booking.