Southwest and LOT Open One-Ticket U.S. Flights

Southwest Airlines and LOT Polish Airlines opened an interline partnership on September 1, 2026, so travelers can buy one itinerary that combines Southwest domestic flights with LOT long-haul service through Los Angeles, Miami, and San Francisco. Southwest lists those three airports as the shared gateways on its airline partners page and says customers can book through LOT Polish Airlines and third-party booking websites.

AirlineGeeks reported the same-day launch and quoted Southwest chief commercial officer Justin Jones saying the relationship gives travelers easier access to U.S. destinations and to new markets in Central and Eastern Europe. If you are connecting a Southwest flight to a LOT Boeing 787 at one of those three airports, shop LOT and agency channels rather than waiting for a Southwest.com path. Cabin details on LOT’s long-haul product are in Deep Arrival’s LOT Polish Airlines 787 business class review.

Single-Ticket Bookings Open Through LOT Channels

The commercial change is the ticket, not a new airplane on a new route. Southwest and LOT now let independently operated flights be sold together, so a traveler can hold one record locator that covers a Southwest segment inside the United States and a LOT segment across the Atlantic. Airways Mag dates the launch to September 1, 2026, and says the available sales channels in that announcement were LOT, travel agents, and travel websites.

That channel list matters at checkout. Southwest.com is not named as a place to build these itineraries, and neither carrier said Rapid Rewards points would post on LOT-operated flights. If a search on Southwest.com shows only Southwest metal, that is consistent with the published launch. Use LOT’s own site or an agency that can ticket both airlines on one document, then save the e-ticket and baggage rules from that booking.

One ticket is the traveler benefit worth paying for. A true interline itinerary is supposed to through-check bags under the fare’s baggage rules and keep both airlines on the hook for a missed connection that they sold together. Read the fare conditions before you pay, especially on cheap mixed-cabin trips that look seamless in a search grid.

Los Angeles, Miami, and San Francisco Are the Gateways

Southwest names only three overlap airports: Los Angeles International, Miami International, and San Francisco International. A hometown Southwest station that is not one of those three still requires a domestic flight to LAX, MIA, or SFO before the LOT Warsaw segment. Dallas, Denver, Chicago, and New York are not listed as LOT gateways under this deal.

Los Angeles and Miami were already on LOT’s U.S. long-haul map. Airways Mag notes that San Francisco is LOT’s newest U.S. city, with Warsaw to San Francisco service that opened May 6, 2026, and four weekly flights scheduled through October 22, 2026. Confirm that frequency still operates before you buy a fall SFO connection.

From Warsaw Chopin, LOT continues across Central and Eastern Europe and to points in India, Japan, and South Korea, according to Airways Mag. Compare that Warsaw transfer with other airline one-ticket options, and use Deep Arrival’s Los Angeles area stay guide if you want a one-night LAX buffer ahead of a once-daily 787.

The Partnership Is an Interline, Not a Codeshare

Airways Mag is explicit that the September 1, 2026, deal is not an announced codeshare. Neither airline said it would place its marketing code on the other’s flights. Expect a Southwest flight number on the Southwest segment and a LOT flight number on the LOT segment, even when both print on one itinerary.

One interline document is still an upgrade from two separate tickets, because the selling carrier has a path to rebook a missed connection it sold. It does not change who operates the 787 or whose bag size limits apply. Follow each carrier’s boarding rules on that airline’s metal.

Southwest identified LOT as its 11th named airline partner, Airways Mag reported. The partner page also lists Icelandair, Air Premia, All Nippon Airways, China Airlines, Condor, EVA Air, Philippine Airlines, Singapore Airlines, TAP Air Portugal, and Turkish Airlines. Do not mix LOT’s three gateways with Icelandair’s Baltimore and Denver list.

Bags Still Clear Customs at the First U.S. Airport

Airways Mag cites LOT interline guidance that travelers check in with the airline operating the first segment and that checked bags can be tagged to the final destination under the itinerary’s baggage and fare conditions. Ask for the final-city tag at the first desk and photograph the bag receipt.

Eastbound trips still stop at the U.S. border. Passengers arriving from abroad and connecting inside the United States generally must collect checked bags for customs at the first U.S. port of entry, even when the tag names a later city. Budget time at LAX, MIA, or SFO for that collect-and-recheck step, then drop the bags onto Southwest.

Baggage allowance follows the ticketed fare, not the more generous of the two airline websites. Confirm piece and weight limits on the e-ticket, and keep liquids and batteries in a carry-on both carriers will accept at the first security checkpoint.

LOT Joins Southwest’s International Partner List

Southwest’s first international interline, with Icelandair, began in February 2025, and Philippine Airlines followed in November 2025. The LOT launch on September 1, 2026, follows that pattern: a foreign carrier sells the long-haul, Southwest fills U.S. cities behind a few coastal gateways, and Southwest.com is not always the storefront. Jones framed it as two-way access, LOT into more of the United States and Southwest customers into Central and Eastern Europe.

No extra frequencies came with the announcement. Airways Mag notes that Southwest did not add routes or extra flights. The 787s already scheduled to Los Angeles, Miami, and San Francisco are the aircraft you board. Recheck the Warsaw timetable, especially SFO after October 22, 2026, before you buy nonrefundable hotels.