Loyalty glossary · 4. Airline-specific (30)
Interline
Interline is a commercial arrangement between airlines that lets a member earn points in one programme on flights operated by another carrier, and to redeem those points for award seats on that other carrier. It extends both accrual and award availability beyond the home airline's own metal.
Interline partnerships are the difference between a programme that works only on one airline and a programme that works across a network. An airline cannot offer meaningful global coverage on its own metal, so it signs interline agreements to let members earn and redeem on other carriers. The key distinction is that interline is not the same as an alliance. Two airlines can have an interline agreement without belonging to the same alliance.
Accrual is where the member sees the first benefit. Fly on an interline partner and the points credit to the home programme, not to a separate partner account. The accrual rate depends on the fare class, the operating carrier, and the published partner chart. A cheap deep discount economy fare on a partner often earns a lower percentage than the same fare class on the home airline. That asymmetry is deliberate and is rarely explained clearly.
Work the numbers before believing the marketing. A member pays 600 dollars for an interline itinerary on a partner airline and earns 6,000 points, because the partner chart credits 10 points per dollar on that fare class. At a conservative valuation of 0.8 cents per point, those 6,000 points are worth 48 dollars, or 8 percent of the fare. If the same member flew the home airline and earned 20 points per dollar, the value would be 96 dollars, a difference of 48 dollars on the same ticket price.
Award availability on an interline partner is always tighter than revenue availability. A partner may release only 20 percent of its award seats to other programmes and hold the remaining 80 percent for its own members. That is why an award chart can show a seat that never appears in search results. Under ASC 606, every interline point issued is a separate performance obligation. The programme must defer revenue equal to the estimated value of those points, usually between 0.5 and 1 cent per point, until redemption or expiry.
The interline model is sold as seamless, but the member bears the hidden cost. A programme that advertises 20 partners rarely tells you that only 2 partners have real award availability. The real test of an interline partnership is not the number of partners, it is the share of requests that return a bookable award. If that share is not published, assume it is low and price your points accordingly.