Civil Law and Airline Code-Sharing Agreement Litigation in Europe

1. Introduction

An airline code-sharing agreement is an arrangement under which one airline markets or sells a flight using its own airline code, while another airline actually operates the aircraft and flight.

For example:

• Airline A sells the ticket and places its flight number on the ticket.
• Airline B actually operates the aircraft.
• The passenger may have a contract primarily with Airline A, while Airline B physically performs the flight.

This creates an important legal distinction between:

1. contractual carrier / marketing carrier — the airline with which the passenger contracts; and
2. operating air carrier — the airline actually performing the flight.

European litigation concerning code-sharing commonly involves:

• flight cancellation;
• long delay;
• missed connections;
• denied boarding;
• baggage loss;
• passenger injury;
• jurisdiction;
• contractual liability;
• Regulation 261/2004 compensation;
• Montreal Convention liability;
• recourse between the two airlines;
• wet leasing;
• interline arrangements;
• allocation of liability under the code-share agreement.

The CJEU has developed particularly important jurisprudence on this distinction.

2. Meaning of Code Sharing

A code-share arrangement generally has two commercial dimensions.

Marketing airline

The airline:

• sells the ticket;
• advertises the route;
• may place its flight number on the itinerary;
• may have the principal contractual relationship with the passenger.

Operating airline

The airline:

• provides the aircraft;
• operates the flight;
• provides flight crew;
• performs the actual transportation.

Therefore:

Ticket seller ≠ necessarily aircraft operator.

This distinction is central to European civil litigation.

3. Principal European Legal Framework

Code-sharing disputes can involve several legal instruments.

A. Regulation 261/2004

Deals principally with:

• denied boarding;
• cancellation;
• long delay;
• assistance;
• standardised compensation.

Its central concept is the “operating air carrier.”

B. Montreal Convention 1999

Deals with international air-carriage liability concerning:

• passenger death/injury;
• baggage;
• cargo;
• delay.

C. Brussels I Recast Regulation 1215/2012

Important for:

• jurisdiction;
• recognition and enforcement;
• contractual claims against airlines.

D. Rome I Regulation 593/2008

Can become relevant to contractual choice-of-law questions.

E. Rome II Regulation 864/2007

May become relevant to certain non-contractual claims.

F. National contract and tort law

The internal agreement between the two airlines may generate:

• indemnity;
• contribution;
• breach-of-contract;
• reimbursement;
• negligence claims.

4. Why Code-Sharing Litigation Is Complicated

Consider:

Passenger

↓

Ticket purchased from Airline A

↓

Ticket says Airline A flight number

↓

Actual aircraft operated by Airline B

↓

Flight delayed

↓

Passenger suffers loss.

The immediate questions are:

1. Who is the contractual carrier?
2. Who is the operating carrier?
3. Who owes Regulation 261/2004 compensation?
4. Who owes Montreal Convention liability?
5. Which airline can the passenger sue?
6. Where can proceedings be brought?
7. Can Airline A recover from Airline B?
8. What does their code-share agreement provide?

5. Case Law 1 — České aerolinie v CS and Others, C-502/18

CJEU, 11 July 2019

This is one of the most important European code-sharing decisions.

Passengers purchased a single reservation from České aerolinie for:

Prague → Abu Dhabi → Bangkok

České aerolinie operated the first flight.

The second flight was operated under a code-share arrangement by Etihad Airways, a non-EU carrier.

The second flight arrived approximately 488 minutes late.

The passengers claimed compensation from České aerolinie.

The CJEU held that the passengers could claim Regulation 261/2004 compensation from the EU carrier that operated the first flight, even though the delay occurred on the second flight operated by the non-EU code-share partner.

Key principle

For connecting flights covered by a single reservation, the first operating carrier can remain responsible for the Regulation 261/2004 compensation consequences of a later code-shared leg.

The carrier that pays may subsequently seek reimbursement from the carrier actually responsible for the disruption under applicable national law.

Importance

This prevents a passenger from being forced to unravel the commercial relationship between airlines.

6. Case Law 2 — flightright v Air Nostrum, Joined Cases C-274/16, C-447/16 and C-448/16

CJEU, 7 March 2018

These cases concerned connecting flights operated by different carriers and questions concerning both Regulation 261/2004 and jurisdiction.

The CJEU considered where passengers could bring compensation claims against an operating carrier, including where that carrier was not domiciled in the Member State concerned or had no direct contractual relationship with the passenger.

Key principle

An action concerning Regulation 261/2004 compensation can have a sufficiently contractual character for jurisdictional purposes even though the passenger may not have entered into a direct contract with the particular operating carrier.

Code-share importance

The case demonstrates that:

Absence of a direct ticket contract does not necessarily eliminate the passenger's ability to litigate against the operating carrier.

This is particularly important in multi-airline itineraries.

7. Case Law 3 — United Airlines v Q, C-561/20

CJEU, 7 April 2022

This case involved a connecting journey operated under a code-sharing agreement between United Airlines and Lufthansa.

The CJEU held that United Airlines, which actually operated the relevant connecting flight on behalf of Lufthansa, could qualify as the operating air carrier for Regulation 261/2004 purposes even though the passenger had no direct contract with United Airlines.

The Court emphasized that the absence of a direct contractual relationship with the passenger is not decisive where the operating carrier performs the flight under the relevant contractual arrangement.

Important principle

The legal concept is based on actual operation of the flight, not merely the airline whose name appears on the passenger's ticket.

8. Case Law 4 — Wirth and Others, C-532/17

CJEU, 4 July 2018

Wirth concerned the meaning of an operating air carrier under Regulation 261/2004.

The CJEU stressed that the concept concerns the carrier that actually performs or intends to perform the flight under the relevant contractual relationship.

Importance for code-sharing

The case assists in distinguishing:

Marketing/contractual carrier

from

actual operating carrier.

The distinction matters because Regulation 261/2004 places its passenger-protection obligations principally on the operating air carrier.

9. Case Law 5 — Thomson Airways / CS and Others, C-532/17

The CJEU's analysis in Wirth and related jurisprudence is particularly important where one carrier leases aircraft and crew to another.

A wet lease involves:

aircraft + crew supplied by one carrier to another.

The CJEU explained that an airline which leases an aircraft and crew to another carrier but does not bear operational responsibility for the flight is not necessarily the “operating air carrier” for Regulation 261/2004 purposes.

Key principle

Providing aircraft and crew does not automatically equal operating responsibility.

The Court focused on the actual performance and operational responsibility of the flight.

Code-share relevance

This becomes important where:

• Airline A markets the flight;
• Airline B operates it;
• Airline C supplies aircraft and crew.

There can therefore be three different commercial actors with different legal roles.

10. Case Law 6 — flightright GmbH v Iberia Express, C-186/17

This line of CJEU jurisprudence concerned the relationship between contractual and operating carriers in multi-leg/code-share arrangements.

The Court's analysis recognized that Regulation 261/2004 was not specifically designed around the complex commercial structure of modern code sharing, where:

one airline issues the ticket while different operating carriers perform different legs.

Principle

The passenger-protection system must be applied to the operating carrier structure, rather than allowing commercial arrangements between airlines to defeat passenger rights.

11. Case Law 7 — flightright v Iberia, C-186/17

This jurisprudence is also important for connecting flights because European law treats a journey consisting of several flights covered by a single reservation as a unified passenger journey for certain Regulation 261/2004 purposes.

Consequently, a passenger cannot necessarily be required to treat each flight leg as a completely independent transaction.

Example

Delhi → Frankfurt → Madrid

Single booking:

• Airline A operates Delhi–Frankfurt.
• Airline B operates Frankfurt–Madrid.
• Second leg causes substantial delay.

The passenger's rights can depend on:

• single reservation;
• departure point;
• destination;
• EU applicability;
• identity of operating carriers;
• nature of the code-share.

12. Case Law 8 — SP v KLM, C-367/20

CJEU, 12 November 2020

This case concerned a connecting journey involving a third-country carrier operating one segment under a code-share agreement.

The reference concerned whether a passenger could claim Regulation 261/2004 compensation against the EU carrier through which the journey was reserved where the disruption occurred on the first segment operated by a non-EU carrier.

Importance

It illustrates that code-share litigation depends heavily on:

• where the journey began;
• where the journey ended;
• which carrier operated each segment;
• whether the reservation was single;
• whether an EU carrier was involved;
• which segment experienced the disruption.

13. Case Law 9 — flightright v Austrian Airlines / Package Travel Context, C-215/18

This CJEU decision examined the contractual character of passenger compensation claims even where the passenger's flight was supplied as part of a package.

The Court held that a compensation claim against an operating carrier can constitute a matter relating to a contract even where the passenger has no direct contract with that operating carrier.

Importance

It reinforces the broader principle that:

The absence of a direct ticket contract is not automatically decisive for jurisdiction or passenger-rights litigation.

14. Case Law 10 — Krijgsman, C-302/16

CJEU, 11 May 2017

Krijgsman is important for the relationship between passenger rights and third-party arrangements.

The Court emphasized that an airline cannot necessarily escape its Regulation 261/2004 obligations merely because the disruption resulted from arrangements involving another party.

Importantly, the airline that pays compensation may have a right of recourse against the person responsible, under applicable national law.

This principle is expressly reflected in the code-sharing jurisprudence. In České aerolinie, the CJEU relied on this mechanism when discussing recovery between code-share partners.

15. Code-Sharing and Regulation 261/2004

The most important practical distinction is:

Contractual carrier

The airline with whom the passenger contracted.

Operating carrier

The airline that actually performs the flight.

Under Article 3(5) of Regulation 261/2004, an operating carrier without a direct passenger contract can still be required to perform obligations under the Regulation on behalf of the person who has the passenger contract.

This structure prevents airline contractual arrangements from undermining passenger protection.

16. Code-Sharing and Flight Delay

Suppose:

Passenger books Airline A

↓

Airline A issues ticket

↓

Airline B operates flight

↓

Flight delayed 5 hours.

The legal analysis asks:

1. Was Airline B the operating carrier?
2. Does Regulation 261/2004 apply?
3. Was the flight departing from an EU airport?
4. Was the carrier EU/non-EU?
5. Was this part of a single reservation?
6. Was the final destination reached 3+ hours late?
7. Did extraordinary circumstances exist?

If Regulation 261/2004 applies, the commercial code-share arrangement does not automatically remove the passenger's statutory rights.

17. Code-Sharing and Cancellation

If Airline A sells the ticket but Airline B operates the flight, cancellation litigation may require identification of the operating carrier.

The passenger's rights can include:

• reimbursement;
• rerouting;
• care;
• compensation where Article 7 conditions are met.

The precise obligation depends upon:

• cause of cancellation;
• notice;
• alternative transport;
• extraordinary circumstances;
• applicable Regulation 261/2004 provisions.

18. Code-Sharing and Denied Boarding

Suppose:

Airline A sells ticket

but

Airline B checks passenger in and operates aircraft.

The question becomes:

Which airline's conduct constituted the denied boarding?

This requires identifying the carrier responsible for actual operation and the relevant contractual arrangement.

A passenger should not automatically lose statutory protection merely because two airlines have divided commercial functions.

19. Code-Sharing and Baggage

Baggage claims can involve a different legal framework.

The Montreal Convention generally governs international carriage by air concerning baggage.

A code-share arrangement therefore requires examination of:

• contracting carrier;
• actual carrier;
• baggage receipt;
• journey;
• location of loss/damage;
• applicable Convention provisions;
• any national implementing rules.

The precise liability allocation between the airlines may then depend on the Convention and their inter-airline agreement.

20. Code-Sharing and Passenger Injury

Suppose:

Airline A sells ticket

↓

Airline B operates aircraft

↓

Passenger injured during flight.

Potential legal issues include:

• Montreal Convention;
• carrier status;
• “accident”;
• causation;
• applicable liability limits;
• contributory fault;
• insurance;
• recourse between airlines.

A passenger claim and an inter-airline indemnity dispute should be treated separately.

21. Internal Code-Share Agreement Between Airlines

The commercial agreement can contain provisions dealing with:

• operational responsibilities;
• scheduling;
• ticketing;
• baggage;
• passenger complaints;
• compensation;
• insurance;
• indemnification;
• safety;
• aircraft maintenance;
• crew;
• disruption management;
• data sharing;
• regulatory compliance;
• dispute resolution.

Therefore, after determining the passenger's statutory rights, a second question arises:

Which airline ultimately bears the economic loss between the airlines?

22. Passenger Claim vs Recourse Claim

This is one of the most important distinctions.

Passenger claim

Passenger → airline

may arise under:

• Regulation 261/2004;
• Montreal Convention;
• contract;
• national law.

Recourse claim

Airline A → Airline B

may arise under:

• code-share agreement;
• indemnity;
• contribution;
• national contract law;
• applicable procedural law.

In České aerolinie, the CJEU expressly recognized the possibility of the carrier that paid compensation seeking redress from the carrier responsible for the delay.

23. Contractual Liability Between Airlines

A code-share agreement may impose obligations beyond statutory passenger rights.

Examples:

Airline B promises

“Airline B shall operate all flights in accordance with applicable safety regulations.”

Failure may produce a contractual claim.

Airline B promises

“Airline B shall reimburse Airline A for passenger compensation caused by Airline B's operational failure.”

This can create a recourse claim even though the passenger has already recovered from Airline A.

24. Indemnity Clauses

An agreement may provide:

Operating carrier pays passenger compensation

↓

Operating carrier reimburses marketing carrier

or alternatively:

Marketing carrier pays passenger

↓

Marketing carrier recovers from operating carrier.

The enforceability and interpretation of such clauses depend on:

• governing law;
• wording;
• mandatory EU passenger rights;
• applicable national contract law;
• causation;
• exclusions;
• limitation clauses.

25. Jurisdiction

Code-sharing disputes can produce complex jurisdiction questions.

Possible connecting factors include:

• airline domicile;
• place of departure;
• place of arrival;
• contractual place of performance;
• passenger residence in certain contexts;
• agreed jurisdiction between commercial parties.

The flightright jurisprudence demonstrates the importance of EU jurisdiction rules in multi-carrier flight disputes.

26. Choice of Law

A code-share contract may contain:

“This agreement shall be governed by English law.”

or:

“French law shall apply.”

But the airline-to-airline agreement and passenger contract are not necessarily governed by the same law.

Therefore:

Passenger contract

may have one applicable law,

while:

Code-share agreement

may have another.

Mandatory EU aviation rules may nevertheless apply independently of contractual choice-of-law provisions.

27. Single Booking vs Separate Tickets

This distinction is critical.

Single reservation

Example:

Delhi → Paris → New York

one booking/reference.

European jurisprudence provides strong passenger protection where the journey is treated as a connected itinerary.

Separate bookings

Example:

Delhi → Paris — separate ticket

Paris → New York — separate ticket.

The legal analysis can be substantially different.

Therefore, litigation should always establish:

• PNR;
• ticket number;
• booking date;
• whether flights formed one reservation;
• operating carriers;
• marketing carriers.

28. Code-Share vs Interline Agreement

These should not automatically be treated as identical.

Code sharing

One airline may place its code on another airline's operated flight.

Interline

Airlines agree to recognise each other's tickets and connect journeys without necessarily placing one airline's flight number on the other's flight.

The legal consequences can differ depending on:

• the particular agreement;
• ticket structure;
• Regulation 261/2004;
• Montreal Convention;
• applicable national law.

Current CJEU litigation has continued to raise questions concerning connecting flights involving code-share and interline structures, showing that the distinction can matter in future cases.

29. Wet Lease vs Code Share

These concepts should also be distinguished.

Code share

Airline A sells/markets a flight operated by Airline B.

Wet lease

Airline A uses an aircraft and crew supplied by Airline B.

The CJEU has held that merely supplying an aircraft and crew does not necessarily make the lessor the operating air carrier under Regulation 261/2004 where it does not bear operational responsibility.

Thus:

Commercial branding ≠ operating responsibility

and

aircraft ownership/crew provision ≠ necessarily operating responsibility.

30. Evidence in Code-Share Litigation

Important documents include:

Passenger evidence

• ticket;
• itinerary;
• boarding pass;
• PNR;
• booking confirmation;
• baggage receipt.

Airline evidence

• code-share agreement;
• operating agreement;
• interline agreement;
• wet-lease agreement;
• flight logs;
• operational control records.

Disruption evidence

• delay records;
• cancellation notice;
• aircraft technical report;
• crew records;
• airport records;
• weather records;
• operational messages.

Commercial evidence

• indemnity clause;
• insurance;
• passenger-compensation allocation;
• reimbursement invoices.

31. Liability Matrix

32. Important Principle: Code Share Does Not Contract Out of EU Passenger Rights

Airlines cannot simply use a commercial agreement to eliminate mandatory passenger protections.

For example:

“Airline A and Airline B agreed that Airline B is responsible.”

That clause may be highly relevant between A and B, but it does not necessarily determine the passenger's statutory rights under Regulation 261/2004.

This distinction is particularly clear from České aerolinie, where the passenger could pursue the EU carrier despite the second flight being operated by the code-share partner.

33. Article 13 Recourse

Article 13 of Regulation 261/2004 is particularly important for code-sharing.

The passenger may receive statutory compensation from the carrier legally responsible under the Regulation.

The carrier that pays can then seek recovery from another person responsible for the disruption under applicable national law.

Therefore:

Passenger protection first

↓

Commercial allocation of responsibility later.

This approach prevents passengers from being forced to resolve complicated airline-to-airline contractual disputes themselves.

34. Example 1 — EU Departure

Passenger books:

Paris → Doha → Bangkok

• Airline A: EU carrier, sells complete itinerary.
• Airline B: non-EU carrier, operates second leg.
• First flight operated by A.
• Second flight delayed 6 hours.
• Single reservation.

Under the reasoning of České aerolinie, C-502/18, the passenger may in the circumstances bring the Regulation 261/2004 compensation claim against the EU carrier that operated the first leg, despite the delay occurring on the second code-shared leg.

The paying carrier may then seek redress from the responsible operating carrier.

35. Example 2 — EU Carrier Merely Marketing

Passenger purchases a ticket from Airline A.

Airline B actually operates the flight.

Airline A's flight number appears on the ticket.

The key question is not simply:

“Whose flight number appears?”

The court must examine who actually performed the flight and the relevant contractual relationship.

This follows the CJEU's operating-carrier jurisprudence.

36. Example 3 — Wet Lease

Airline A markets a flight.

Airline B supplies:

• aircraft;
• pilots;
• cabin crew.

But Airline A retains operational responsibility.

The fact that B supplied aircraft and crew does not automatically make B the Regulation 261/2004 operating carrier. The CJEU requires examination of actual operational responsibility.

37. Example 4 — Passenger Injury

Passenger buys:

Airline A ticket

Flight operated by:

Airline B

Passenger suffers injury during an aviation accident.

The legal analysis should be divided:

Passenger → carrier

Montreal Convention.

Airline A → Airline B

Code-share agreement/indemnity/recourse.

Carrier → manufacturer

Potential product-liability or contractual claim if an aircraft defect caused the accident.

One incident can therefore generate three different civil proceedings.

38. Main Legal Problems in Code-Share Litigation

1. Identity of carrier

Who actually operated?

2. Contractual relationship

Who sold the ticket?

3. Single reservation

Were all segments part of one booking?

4. Territorial scope

Did the journey begin in the EU?

5. Operating responsibility

Who controlled the flight?

6. Cause of disruption

Which carrier caused the delay/cancellation?

7. Passenger compensation

Does Regulation 261/2004 apply?

8. Recourse

Can the paying airline recover from its partner?

9. Jurisdiction

Where may proceedings be brought?

10. Applicable law

Which law governs the airline-to-airline agreement?

39. Six Core Cases for Examination

40. Key Legal Principles

1. Marketing carrier and operating carrier are legally distinct concepts.
2. The flight number printed on a ticket is not necessarily decisive.
3. Actual operation of the flight is central to Regulation 261/2004.
4. A passenger does not necessarily need a direct contract with the operating carrier. 
5. A single reservation can unify connecting flights for passenger-rights purposes.
6. Code sharing cannot simply eliminate mandatory EU passenger protections.
7. The carrier paying compensation can potentially seek recovery from the responsible carrier. 
8. Wet leasing and code sharing are legally distinct.
9. Aircraft ownership or provision of crew does not automatically determine operating-carrier status. 
10. Montreal Convention claims and Regulation 261/2004 claims must be analysed separately.
11. The passenger's claim and the airlines' internal indemnity dispute are separate legal relationships.
12. Jurisdiction can exist even where the passenger lacks a direct contract with the operating carrier. 
13. The code-share contract remains important for contribution, indemnity and allocation of commercial risk.
14. The exact result depends heavily on the itinerary, reservation structure, operating responsibility and cause of the disruption.

41. Practical Legal Test

For an airline code-sharing dispute, use this sequence:

Step 1: Identify every airline.

Step 2: Identify the marketing/contractual carrier.

Step 3: Identify the actual operating carrier for each flight.

Step 4: Determine whether the itinerary was one reservation.

Step 5: Determine departure and final destination.

Step 6: Establish whether Regulation 261/2004 applies.

Step 7: Identify the disrupted flight.

Step 8: Determine the cause of disruption.

Step 9: Apply Regulation 261/2004 to passenger compensation.

Step 10: Apply the Montreal Convention separately where relevant.

Step 11: Examine the code-share/interline/wet-lease agreement.

Step 12: Determine indemnity and recourse between carriers.

Step 13: Determine jurisdiction.

Step 14: Determine applicable contractual and national law.

Conclusion

Airline code-sharing litigation in Europe is fundamentally a problem of allocating legal responsibility among the contractual carrier, operating carrier and other aviation participants. EU jurisprudence strongly focuses on the actual operation of the flight rather than allowing the passenger's statutory rights to depend entirely on private commercial arrangements between airlines.

The most important authority is České aerolinie, C-502/18, which establishes that, in the specified circumstances, an EU carrier that operated the first flight of a single-reservation connecting journey can owe Regulation 261/2004 compensation even where the serious delay occurred on a later flight operated by a non-EU code-share partner. The paying carrier can then pursue the responsible carrier for reimbursement under applicable law.

United Airlines v Q, C-561/20 further demonstrates the importance of the actual operating carrier, while flightright, Wirth, Krijgsman, and SP v KLM develop the related rules on operating-carrier status, jurisdiction, recourse and multi-carrier connecting flights.

Ultra-short revision formula

Passenger Contract + Marketing Carrier + Operating Carrier + Single Reservation + Disrupted Leg + Regulation 261/2004 + Montreal Convention + Code-Share Agreement + Jurisdiction + Recourse = European Code-Sharing Litigation.