Lost baggage on a connecting flight: which airline do you claim from?

Why each airline points at the other

A connecting journey booked as one ticket can still be flown by two or three different airlines. You hand your suitcase to the first carrier at check-in, it is meant to be transferred airside at the connection, and you collect it (or do not) at the final airport. When it goes missing, each airline has an incentive to say the loss happened on somebody else's leg.

That is a real practical problem, not a legal one. The Montreal Convention was written precisely so a passenger does not have to prove which airline lost the bag before anyone accepts the claim. For baggage on a successive-carrier journey it names two carriers you can always go to.

What the Montreal Convention actually says

Article 36 covers carriage performed by several successive carriers that the parties treated as a single operation — which is what a through-checked connecting ticket is. Its third paragraph deals specifically with baggage and gives the passenger a right of action against two named carriers, not one.

The text is short and worth reading in the airline's own words when a desk agent tells you it is not their problem: the passenger "will have a right of action against the first carrier, and the passenger … who is entitled to delivery will have a right of action against the last carrier, and further, each may take action against the carrier which performed the carriage during which the … loss, damage or delay took place. These carriers will be jointly and severally liable."

• First carrier: the airline you checked the bag in with at the start.
• Last carrier: the airline that operated your final leg and was to deliver the bag.
• The carrier on whose specific leg the loss happened, if that is ever established.
• "Jointly and severally liable" means you can pursue the whole claim against either — they sort the split out between themselves.

First carrier or last carrier — which to pick

Because both are liable, the choice is practical, not legal. The last carrier is the airline whose staff you stand in front of at the final airport, so it is almost always where the report is opened and where tracing starts. That does not make it the only airline you can hold responsible.

Pick by two questions: which airline will actually process and pay a claim without endless referral, and which one operated the leg where the loss most plausibly occurred. If the last carrier stalls, the first carrier's liability is an equal, independent route — you are not appealing the last carrier's decision, you are exercising a separate right the Convention gives you.

• Report at the final airport with the last carrier before you leave — that opens the file.
• Keep the option of the first carrier open; do not sign anything that waives it.
• If either airline tells you "claim from the other one", note who said it and when.
• For a codeshare, the operating airline of the leg, not the marketing airline on your ticket, is the carrier that matters.

Report before you leave the final airport

Whichever airline you ultimately claim from, the report has to be made at the arrivals baggage desk before you exit, and it has to describe the whole journey, not just the last leg. A Property Irregularity Report opened at the final airport should list every flight and carrier so that the tracing team can search each transfer point.

Get a single tracing reference that covers the connecting journey. If the desk issues a reference tied only to the last leg, ask them to record the full routing and the original bag tag number from check-in, because that tag is what links the bag to the first carrier.

• Give the full routing: every flight number, date and operating airline.
• Copy the original baggage tag number from check-in, digit for digit.
• Confirm the tracing reference covers the whole journey, not one leg.
• Ask, in writing if you can, which airline's portal should receive the expense claim.

Deadlines and the liability limit

The written-complaint clock is the same as for any Montreal Convention baggage case and it does not restart because the journey had a connection. For damaged baggage the written complaint must reach the carrier within 7 days of receiving the bag; for delayed baggage it is 21 days from the date the bag is delivered back to you. If the bag never arrives, it is treated as lost once 21 days have passed since it should have arrived.

The liability limit is also unchanged by the number of carriers. ICAO raised the baggage limit to 1,519 Special Drawing Rights per passenger from 28 December 2024, and that is a per-passenger ceiling for the whole journey, not per airline and not per leg. It is a maximum on proven loss, not an automatic payout.

Build one claim, aimed at the right airline

Assemble the same evidence you would for any baggage claim — the PIR reference, the original bag tag, boarding passes for every leg, delivery confirmation and itemised receipts — and file it once, against the carrier you have chosen, through that airline's official baggage claim route. Keep the confirmation, because the first carrier's liability stays available if the chosen airline refuses without good reason.

For the exact report, claim and appeal links for each airline on your journey — first and last carrier both — start from the BagClaim airline claim guides and work from the operating carrier of each leg, not the name printed on the ticket cover.

• PIR or tracing reference covering the full routing
• original check-in baggage tag and boarding passes for every leg
• delivery confirmation or the date the bag was declared lost
• itemised receipts with a short necessity note for each cost
• the operating airline of each leg, identified before you file