When your codeshare flight goes wrong, the airline that operates the plane handles the on-the-ground problems—rebooking, meals, hotels—but the airline that sold you the ticket (the "marketing carrier") is who you go to for refunds and is legally on the hook under US DOT rules. That split trips up a lot of travelers, so before you spend an hour on hold with the wrong airline, figure out which carrier is which. Check your ticket: it says something like "United flight UA8501 operated by Lufthansa." United sold it; Lufthansa flies it.
What a Codeshare Flight Actually Is
A codeshare is one physical flight sold under two or more airlines' flight numbers. Airlines do this to fill seats and extend their networks without adding planes. If you book Delta to fly from Atlanta to Amsterdam and then onward to Berlin, Delta might operate the transatlantic leg while KLM operates the short hop to Berlin—but both legs show up on your Delta itinerary with Delta flight numbers.
There are two roles you need to keep straight:
- Marketing carrier: The airline whose flight number and name you booked under. This is who took your money and whose website you used.
- Operating carrier: The airline that actually owns and staffs the aircraft you'll board.
Your boarding pass and confirmation email will always disclose this. US DOT rules require carriers to tell you the operating airline at the time of booking, on your itinerary, and again if it changes. Look for the phrase "operated by."
Who's Responsible When Things Go Wrong
Here's the practical breakdown, because responsibility genuinely splits depending on the problem.
| Problem | Who to contact | Why |
|---|---|---|
| Flight delayed or cancelled | Operating carrier (at the airport); marketing carrier for refunds | The operating airline controls the aircraft and rebooking at the gate |
| Refund for cancellation/major change | Marketing carrier | They took your payment and issued the ticket |
| Lost, delayed, or damaged bags | Operating carrier of the flight you were on | They handled your bag |
| Denied boarding / bumping | Operating carrier | They control the passenger load |
| Seat assignments, upgrades, meals booked in advance | Marketing carrier first, then operating | Requests don't always transfer between systems |
| Complaints / DOT filing | File against the marketing (ticketing) carrier | DOT holds the ticketing carrier accountable |
The most common failure point: seat assignments and special requests don't always sync between the two airlines' reservation systems. You picked seat 14C on the marketing carrier's site, but the operating carrier's system never received it. That's why families get split up—so if you're traveling with kids, confirm seats directly with the operating carrier and know your rights under the DOT fee-free family seating guarantee.
Your Refund Rights Under the 2024 DOT Rule
This is where US travelers have real, enforceable protection—and it applies to codeshares. Under the DOT refund rule that took effect in late 2024, if your flight is cancelled or significantly changed and you choose not to travel, you're owed an automatic cash refund to your original payment method. You don't have to accept a voucher or travel credit.
The rule defines "significant change" specifically:
- A departure or arrival time that moves by 3 hours or more for a domestic flight, or 6 hours or more for an international flight
- A change to your departure or arrival airport
- An added connection
- A downgrade to a lower class of service
- A change to a connection or aircraft that's less accessible for a passenger with a disability
For a codeshare, you request that refund from the marketing carrier—the one that sold you the ticket. They're responsible under the rule because they hold your payment. The refund must be issued within 7 business days if you paid by credit card, or 20 calendar days for cash or check.
One critical thing about US rules: there is no mandatory delay-compensation law like the EU's EC261. If your codeshare is delayed three hours, no US airline owes you a cash payout for the delay itself. What they owe are amenities (meals, hotel for overnight delays within their control) per their contract of carriage, and a refund only if you choose not to travel. Don't let anyone convince you a domestic delay entitles you to hundreds of dollars in compensation—it doesn't.
EC261 can apply to a codeshare if the flight departs from an EU airport or is operated by an EU carrier flying into the EU. If your delayed leg took off from Frankfurt or Paris, you may have EU261 rights even on a US-marketed ticket—claim those against the operating carrier.
Baggage and Denied Boarding on Codeshares
For checked bags, the operating carrier handles your claim, but liability limits are set by DOT. On domestic US flights, an airline's liability for lost, delayed, or damaged checked bags is capped at $3,800 per passenger. On international itineraries, the Montreal Convention applies with a limit of roughly 1,288 Special Drawing Rights (about $1,700–$1,800, depending on exchange rates).
File the bag claim before you leave the airport, and keep your bag tags and boarding pass. On a codeshare, the operating carrier of the flight your bag was on owns the problem—even if you booked through someone else.
Denied boarding (getting bumped from an oversold flight) is one area where US law does require cash compensation, and it's the operating carrier's obligation:
- 1 to 2 hours late to your destination (domestic): 200% of your one-way fare, capped at $1,075
- More than 2 hours late (domestic) or more than 4 hours international: 400% of your one-way fare, capped at $2,150
This applies only to involuntary denied boarding. If you volunteer to give up your seat for a voucher, you've accepted whatever deal you negotiated and these federal minimums don't apply. Also note: this covers bumping, not cancellations. A cancelled codeshare flight falls under the refund rules above, not denied-boarding compensation.
How to Protect Yourself When Booking a Codeshare
Codeshares are usually fine—the whole point is a seamless single ticket. But a few habits keep you out of trouble:
- Book on one ticket, not two. A true codeshare is a single ticket, which means the airlines protect your connection if the first leg is late. This is very different from buying two separate tickets and hoping the connection works. If you're stitching your own trip together, read our guide on the risks of connecting on a separate ticket first.
- Confirm seats with the operating carrier. A day or two after booking, log in to the operating airline's site with your confirmation number and verify your seat transferred.
- Check baggage rules for the operating carrier. Fees and allowances usually follow the marketing carrier's fare rules on a through-ticket, but low-cost partners sometimes differ. Confirm so you're not surprised at the counter.
- Know your elite status reach. Miles and perks often carry across alliance partners on codeshares, but not always at the same rate. If you're weighing whether the loyalty game pays off, see whether chasing airline elite status is worth it in 2026.
- Screenshot everything. Save your itinerary showing both flight numbers and the "operated by" line. When something goes wrong, that document tells you exactly who to chase.
- Give yourself a buffer. Codeshares often involve terminal or even airport changes between partners. If your layover is tight, know how to make the most of it—or how to survive if it stretches long—with our long layover survival guide.
Frequently Asked Questions
My codeshare was cancelled. Which airline do I call for a refund?
Call the marketing carrier—the airline whose name and flight number you booked under and who charged your card. Under the 2024 DOT rule, they must give you an automatic cash refund to your original payment method if you choose not to travel, within 7 business days for credit card purchases. For same-day rebooking at the airport, though, talk to the operating carrier's gate agents since they control the plane.
Do my frequent flyer miles work on a codeshare flight?
Usually yes, if the airlines are alliance partners or have a partnership agreement. You typically earn miles in the program of the marketing carrier, but sometimes at a reduced rate based on your fare class. Enter your frequent flyer number with the operating carrier at check-in too, and check both programs after the flight to make sure the miles posted.
Can I get EU261 compensation on a US-booked codeshare?
Possibly. EC261 applies to any flight departing an EU airport, or any flight into the EU operated by an EU-based carrier—regardless of which airline sold the ticket. So if your delayed or cancelled codeshare leg departed from an EU country, you may be entitled to €250–€600 in compensation. Claim it from the operating carrier. US-to-US and US-to-non-EU flights get no such payout.
Whose baggage rules apply on a codeshare?
On a single through-ticket, the marketing carrier's fare rules generally govern your baggage allowance and fees for the whole journey. But you file lost or damaged bag claims with the operating carrier of the flight your bag was on. Liability is capped at $3,800 for domestic checked bags and roughly $1,700–$1,800 under the Montreal Convention for international itineraries.