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Points redemption

What is a codeshare flight?

By Jovoney MortonLast updated July 15, 2026
DEFINITION SNIPPET

A codeshare flight is one where a single physical flight is operated by one airline (the operating carrier) but sold under the flight number of one or more partner airlines (the marketing carriers). For example, a flight booked on United's website with a "UA" flight number may actually be operated by Lufthansa. Codeshares are common across airline alliances and bilateral partnerships, and they are a key mechanism that allows travelers to earn and redeem miles with their preferred loyalty program on flights they would not otherwise have access to.

TL;DR / Key takeaways

    • One flight, two (or more) flight numbers: The operating carrier flies the plane; the marketing carrier sells seats under its own code. You may book “UA8838” and board a Lufthansa aircraft.
    • Miles earning usually works, but check first: You can typically credit miles to the marketing carrier’s program, but earning rates vary by fare class and carrier. Non-alliance codeshare partners may credit miles differently or not at all.
    • Codeshares unlock partner award redemptions: Many loyalty programs use codeshare agreements to make partner flights bookable with your miles, often at favorable redemption rates. This is one of the best ways to use transferable points currencies.
    • The on-board experience belongs to the operating carrier: Seats, meals, in-flight entertainment and service standards are set by the airline operating the plane, regardless of which airline sold you the ticket.
    • Status perks and baggage rules vary: Benefits tied to your elite status may not apply equally across codeshare partners, and baggage policies can differ depending on which carrier issued your ticket. Always verify before you fly.

How codeshare flights work

When two airlines enter a codeshare agreement, one airline (the operating carrier) flies the aircraft while its partner (the marketing carrier) sells seats on that flight under its own airline designator and flight number. Both codes appear on departure boards, so the same flight may show several different numbers simultaneously. All passengers board the same plane, regardless of which airline sold them their ticket.

A real-world example: United and Lufthansa are both Star Alliance members and long-standing codeshare partners. You can book flight UA8838 on united.com from Newark (EWR) to Frankfurt (FRA), but the booking page notes that Lufthansa operates the flight. Lufthansa sells that same service as LH403. Either booking puts you on the same aircraft.

Check-in is typically handled by the operating carrier. If you booked through the marketing carrier’s website, you may be redirected to the operating carrier’s check-in desks or website when you arrive at the airport. Reviewing your itinerary details before travel, including which airline handles check-in, saves confusion at the gate.

Because the operating carrier controls the product, the cabin experience reflects its standards. A transatlantic flight on a Lufthansa-operated 747-8 will differ from a United-operated 767, even if you booked both through united.com. In premium cabins, especially, it is worth checking the operating carrier and reviewing its product before booking. 

RELATED: What are codeshare flights, and how do they work

How codeshares affect your miles and points

For points travelers, codeshares matter most because they determine which loyalty programs you can earn and redeem with on a given flight. When you book a codeshare flight, you can usually provide your frequent flyer number for either the operating or the marketing carrier. Earning rates are typically based on the operating carrier’s fare class and elite status, so checking the partner earning chart for your preferred program before booking avoids surprises.

The more powerful opportunity is on the redemption side. Codeshare agreements are the backbone of partner award bookings. When you use American Airlines AAdvantage miles to book a British Airways flight, or Air Canada Aeroplan points to fly Emirates, it is a codeshare (or broader partnership) that makes that redemption possible. This is often where you can find the best value from transferable points currencies: using one program’s points or miles to book a seat on a partner airline at a rate that the partner’s own program does not offer.

Keep in mind that not all codeshare partners are created equal for miles purposes. If the operating carrier is outside your program’s alliance or formal partner list, miles may not accrue at all. A codeshare exists for the airline’s commercial reasons; your eligibility to earn depends on whether your program has a miles-earning agreement with the operating carrier, specifically.

Codeshare flights vs. interline agreements vs. airline alliances

Airlines partner with each other in several ways, and the terms are easy to mix up. The table below clarifies the three most common types.

CategoryCodeshareInterlineAlliance
What it isShared flight number on the same physical flightTicketing agreement to connect itineraries across carriersFormal multilateral partnerships (e.g., Star Alliance, SkyTeam, oneworld)
Flight numberMarketing carrier shows its own code on operating carrier's planeEach carrier keeps its own code; no shared numberEach carrier keeps its own code within alliance framework
Miles earningGenerally earn with marketing or operating carrier's programEarning eligibility depends on carrier agreementsEarn and redeem across all member airlines
Status benefitsMay apply; perks vary by partnerLimited — typically no status reciprocityFull reciprocity across member airlines (with some exceptions)
Common exampleUnited (UA) selling a Lufthansa-operated flightConnecting itinerary across two unaffiliated airlines on one ticketStar Alliance, SkyTeam, oneworld member networks

The practical takeaway: codeshares sit in the middle of the partnership spectrum. They are more operationally integrated than a basic interline ticket (because the marketing carrier’s commercial terms apply to the booking), but narrower in scope than a full alliance membership (because they are bilateral agreements between two specific carriers). Non-alliance codeshare partnerships, like the Air Canada relationship with Emirates and Etihad, can be particularly valuable because they extend your rewards’ ‘ reach to carriers your alliance does not cover. Learn more about transferring miles between frequent flyer programs.

What to watch out for when booking a codeshare flight

Codeshare flights generally work seamlessly, but a few variables are worth confirming before you finalize a booking.

  • Baggage policy: Check-in baggage rules can follow either the marketing carrier or the operating carrier, depending on how your ticket was issued and the specific agreement between carriers. When in doubt, contact the airline that issued your ticket to confirm which policy applies. 
  • Elite status benefits: Priority boarding, lounge access and seat upgrades tied to your status with the marketing carrier may not be recognized by the operating airline, particularly for space-available upgrades or perks the operating carrier does not offer its own elites. Perks vary by partner, so verify before you travel.
  • Seat upgrades with miles: Upgrading a codeshare flight using the marketing carrier’s miles is generally not possible. If you want to upgrade, it is usually easier to do so using the operating carrier’s miles, subject to that carrier’s upgrade availability and policies.
  • Card travel benefits: Some travel benefits tied to a premium travel card, such as companion certificates or travel credits, may be restricted on codeshare flights where the operating carrier differs from the marketing carrier. Review the card’s terms before relying on these benefits for a codeshare itinerary.
  • Delay and cancellation responsibility: When a codeshare flight is delayed or canceled, the operating carrier is responsible for rebooking and care. Contact the operating airline first if something goes wrong at the airport, even if your original booking was with the marketing carrier.

Frequently asked questions about codeshare flights