A codeshare goes one step beyond interlining: instead of each leg selling under its operator's name, one airline, the marketing carrier, fronts the whole connecting journey under its own brand, while the partner keeps flying the aircraft as the operating carrier.
What brand transfer means#
When a codeshare covers a cross-carrier itinerary, passengers see and book it as the marketing carrier's product. The marketing carrier's brand image, market awareness, fares, and fare policy govern the sale, not the operator's. The operator still flies the flight and still controls the seats: codeshares here are free-flow, meaning nothing is blocked off or partitioned; the operator's inventory is simply sold under the partner's flag.
In practice, the carrier flying the longest leg of a journey is the one that fronts it, and it can only do so if every other leg is covered by an active codeshare granting it those rights. This is why codeshares are most valuable to a network carrier buying feed from regional partners.
Direction matters#
A codeshare is directional: "we market their flights" and "they market our flights" are two different agreements. Each direction can exist once per pair of airlines, covers the whole network by default, and can be scoped by via-airport or country just like an interline; see Interlining.
The money: distance prorate plus SPA#
Base revenue on a shared itinerary splits by distance, exactly as with interlining. On top of that, the agreement carries a special prorate (SPA) slider from −30% to +30%:
- A positive SPA shifts money toward the operator: the marketing carrier pays a premium for the feed.
- A negative SPA lets the marketing carrier keep more of the pot.
- The operator is always guaranteed at least half of its base distance share, and the shift only applies when the marketing carrier's own leg can fund it.
There are no signing fees; the SPA is the entire commercial term.
Setting one up#
On the Partners → Codeshares page, pick a partner, choose the direction, set scope and the SPA slider, and send the proposal. The counterparty accepts or denies. Statuses mirror the interlining page: Awaiting partner, Offer received, Active, Terminated.
Accepting a codeshare automatically creates a backing interline agreement between you if none exists: codeshares need the connection plumbing underneath, and you'll see that agreement appear on the Interlining page. Terminating the codeshare also ends that backing interline.
Who will sign one#
AI carriers treat codeshares according to their business model: regionals and low-cost carriers will happily operate under a bigger brand, legacy network carriers look to market feeders' metal, and ultra-low-cost carriers refuse all partnerships; see AI carriers. If either airline sits in an alliance whose charter bans external partnerships, proposals outside the alliance are blocked, since codeshares ride on interline rights.