# Southwest Airlines and Singapore Airlines Announce Interline Partnership

_Jun 9 14:54_

Tags: Singapore Airlines, Southwest, Southwest Airlines, KrisFlyer, Rio de Janeiro, loyalty program, policy change, airline, partnership, app & tech

Southwest Airlines and Singapore Airlines have announced an interline partnership, allowing SIA to sell single-ticket connections to its US domestic network at LAX, SEA, and SFO. The deal, announced June 8, 2026, applies baggage and protection rules but does not include KrisFlyer mileage earning on Southwest segments

## Summary

Southwest Airlines and Singapore Airlines announced a new interline partnership during the IATA Annual General Meeting in Rio de Janeiro on June 8, 2026. This agreement allows Singapore Airlines to sell single-ticket journeys connecting to Southwest's US domestic network at three key gateways: Los Angeles (LAX), Seattle/Tacoma (SEA), and San Francisco (SFO). Key details for frequent flyers:
- **Connectivity:** Passengers can seamlessly connect from international SIA flights to nearly 120 Southwest destinations.
- **Mileage:** The partnership is interline only, not codeshare or alliance-based. Singapore Airlines passengers will **not** earn KrisFlyer miles on Southwest-operated flights, nor will Southwest passengers earn on SIA flights.
- **Baggage & Protection:** The Most Significant Carrier (MSC) rule applies for baggage allowance. Passengers are protected against delays and cancellations under the MSC's rules.
- **Availability:** Tickets are available through Singapore Airlines, travel agents, and travel websites. This marks Southwest's expansion into legacy-style interline partnerships, previously limited by IT constraints. While SIA business class passengers may find themselves on Southwest's main cabin, the single-ticket convenience remains the primary benefit

## Why it matters

Affects 3 airline programs (Singapore Airlines, Southwest, Southwest Airlines).

## Sources cited

- [LoyaltyLobby](https://loyaltylobby.com/2026/06/09/singapore-airlines-passengers-can-soon-find-themselves-flying-on-southwest-airlines?omhide=true) — Singapore Airlines Passengers Can Soon Find Themselves Flying On Southwest Airlines!

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