Provisional text
OPINION OF ADVOCATE GENERAL
NORKUS
delivered on 19 June 2025 (1)
Case C‑45/24
Verein für Konsumenteninformation
v
Koninklijke Luchtvaart Maatschappij NV
(Request for a preliminary ruling from the Oberster Gerichtshof (Supreme Court, Austria))
( Reference for a preliminary ruling – Air transport – Regulation (EC) No 261/2004 – Article 8(1) – Reimbursement of the price of a ticket in the event of cancellation of a flight – Commission collected by a person acting as an intermediary between the passenger and the air carrier when the ticket was bought – Conditions for inclusion – Amount of commission allegedly fixed without the air carrier’s knowledge – Burden of proof )
I.      Introduction
1.        The present request for a preliminary ruling, referred by the Oberster Gerichtshof (Supreme Court, Austria) under Article 267 TFEU, concerns the interpretation of Regulation (EC) No 261/2004 of the European Parliament and of the Council of 11 February 2004 establishing common rules on compensation and assistance to passengers in the event of denied boarding and of cancellation or long delay of flights, and repealing Regulation (EEC) No 295/91 (2) and, in particular, Article 8(1)(a) thereof.
2.        The request has been made in
proceedings between the Verein für Konsumenteninformation, an Austrian consumer protection association (‘the VKI’) and Koninklijke Luchtvaart Maatschappij NV (‘KLM’), an airline, concerning the reimbursement of the commission paid to Opodo, an online travel agency, by passengers who had booked their tickets on Opodo’s website and whose flights were cancelled. Those passengers assigned their possible right to reimbursement of that commission, amounting to EUR 95.14, to the VKI, which, by its action, claims payment thereof, together with interest, from KLM on the basis of Article 8(1)(a) of Regulation No 261/2004. KLM contests the merits of that action, submitting that there is no agreement between itself and Opodo concerning that commission and that KLM did not authorise the setting of such commission.
3.        The present case offers the Court of Justice the opportunity to clarify its case-law on the obligation for an air carrier to reimburse the passenger for the commission paid to a third party acting as an intermediary when the ticket was purchased. In particular, it will be necessary to clarify the conditions which the relationship between the intermediary and the air carrier must satisfy in order for an action brought directly against the air carrier on the basis of Article 8(1)(a) of Regulation No 261/2004 to appear justified. Relying on the case-law of the Court, I shall show that it is crucial that the air carrier authorises, at least implicitly, the intermediary’s activity. I shall also explain why the approach adopted by the Court best protects the rights of passengers, without losing sight of the interests of the air carriers.
II.    Legal framework
4.        Recitals 1, 13 and 22 of Regulation No 261/2004 state:
‘(1)      Action by the Community in the field of air transport should aim, among other things, at ensuring a high level of protection for passengers. Moreover, full account should be taken of the requirements of consumer protection in general.
…
(13)      Passengers whose flights are cancelled should be able either to obtain reimbursement of their tickets or to obtain re-routing under satisfactory conditions, and should be adequately cared for while awaiting a later flight.
…
(22)      Member States should ensure and supervise general compliance by their air carriers with this Regulation and designate an appropriate body to carry out such enforcement tasks. The supervision should not affect the rights of passengers and air carriers to seek legal redress from courts under procedures of national law.’
5.        Article 2 of that regulation, entitled ‘Definitions’, provides:
‘For the purposes of this Regulation:
…
(f)      “ticket” means a valid document giving entitlement to transport, or something equivalent in paperless form, including electronic form, issued or authorised by the air carrier or its authorised agent;
(g)      “reservation” means the fact that the passenger has a ticket, or other proof, which indicates that the reservation has been accepted and registered by the air carrier or tour operator;
…’
6.        Article 5 of that regulation, entitled ‘Cancellation’, provides:
‘1.      In case of cancellation of a flight, the passengers concerned shall:
(a)      be offered assistance by the operating air carrier in accordance with Article 8;
…’
7.        Article 8 of Regulation No 261/2004, entitled ‘Right to reimbursement or re-routing’, provides, in paragraph 1 thereof:
‘Where reference is made to this Article, passengers shall be offered the choice between:
(a)      –      reimbursement within seven days, by the means provided for in Article 7(3), of the full cost of the ticket at the price at which it was bought, for the part or parts of the journey not made, and for the part or parts already made if the flight is no longer serving any purpose in relation to the passenger’s original travel plan, together with, when relevant,
–      a return flight to the first point of departure, at the earliest opportunity;
(b)      re-routing, under comparable transport conditions, to their final destination at the earliest opportunity; or
(c)      re-routing, under comparable transport conditions, to their final destination at a later date at the passenger’s convenience, subject to availability of seats.’
8.        Under Article 13 of Regulation No 261/2004, entitled ‘Right of redress’:
‘In cases where an operating air carrier pays compensation or meets the other obligations incumbent on it under this Regulation, no provision of this Regulation may be interpreted as restricting its right to seek compensation from any person, including third parties, in accordance with the law applicable. In particular, this Regulation shall in no way restrict the operating air carrier’s right to seek reimbursement from a tour operator or another person with whom the operating air carrier has a contract. Similarly, no provision of the Regulation may be interpreted as restricting the right of a tour operator or a third party, other than a passenger, with whom an operating air carrier has a contract, to seek reimbursement or compensation from the operating air carrier in accordance with applicable relevant laws.’
III. Facts of the dispute, the procedure in the main proceedings and the questions referred for a preliminary ruling
9.        Passengers had purchased tickets for flights operated by KLM on the Opodo booking portal, a travel agency certified by the International Air Transport Association (IATA) and authorised to issue airline tickets for that airline. They had paid Opodo a total of EUR 2 053.48. As a result of the cancellation of their flights, those passengers were reimbursed EUR 1 958.34 for the price of their tickets. The difference of EUR 95.14, which was not reimbursed, corresponds to Opodo’s agency commission.
10.      When the tickets which are the subject of the dispute in the main proceedings were purchased, KLM had been collaborating with Opodo for at least a decade and there was a ‘Global Incentive’ contract in place between them which provided for certain bonuses for Opodo depending on the number of tickets sold for KLM. However, neither the IATA contracts nor the so-called ‘Incentive’ contracts settled the question whether an agency commission could be charged by Opodo to passengers and, therefore, in any event, those contracts did not state the amount of such commission. Thus, in the present case, KLM claimed that it was not aware of the amount of the agency commission that Opodo charged the passengers.
11.      By its action, the VKI, to which the passengers assigned their claims for reimbursement of the cost of the tickets, is claiming the sum of EUR 95.14 plus interest. The court of first instance upheld the VKI’s action, whereas the appeal court dismissed it. Consequently, the VKI brought an appeal on a point of law against the judgment on appeal before the Oberster Gerichtshof (Supreme Court), which is the referring court.
12.      The referring court states that the Court of Justice has already examined the extent of passengers’ right to reimbursement in the judgment of 12 September 2018, Harms (C‑601/17, EU:C:2018:702; ‘the judgment in Harms’), in which it held that the agency commission must be included in the reimbursement under Article 8(1) of Regulation No 261/2004, unless that commission was set without the knowledge of the air carrier. However, the exception set out by the Court relating to whether or not that air carrier is aware of the commission may, in the referring court’s view, be interpreted in different ways. Thus, the question arises as to, first, how, in practice, the air carrier must have been informed of the existence of the commission and, where appropriate, of its amount and, second, who bears the burden of proof in that regard.
13.      Even though the national courts apply the case-law arising from the judgment in Harms differently, the referring court considers that the air carrier cannot argue that it was not aware of the exact amount of the commission, as long as it was not abnormally high, which it would be for the air carrier to prove. In that regard, the air carrier must assume that an agent normally works only for an agency commission.
14.      In those circumstances, the Oberster Gerichtshof (Supreme Court) decided to stay the proceedings and to refer the following questions to the Court of Justice for a preliminary ruling:
‘(1)      Is [Regulation No 261/2004] and in particular Article 8(1)(a) thereof to be interpreted as meaning that the price of the ticket to be taken into consideration for the purpose of determining the reimbursement owed by the air carrier to a passenger in the event of cancellation of a flight also includes the difference between the amount paid by the passenger and the amount received by the air carrier, which corresponds to a commission collected by a person acting as an intermediary between those two parties, if the air carrier, although aware that the other person regularly charges a commission (arrangement fee) for an intermediary service, does not know the amount of that commission in the specific case?
(2)      Does the burden of proving that the air carrier had the necessary knowledge lie with the passenger seeking reimbursement, or is it for the air carrier to prove that it lacked the necessary knowledge of the commission?’
IV.    The procedure before the Court
15.      The order for reference dated 23 November 2023 was received at the Registry of the Court of Justice on that same day.
16.      The parties in the main proceedings and the European Commission submitted written observations within the period prescribed by
Article 23 of the Statute of the Court of Justice of the European Union.
17.      In accordance with Article 76(2) of its Rules of Procedure, the Court did not consider it necessary to hold a hearing.
V.      Legal analysis
A.      Preliminary observations
18.      Reimbursement of the price of tickets by airlines is one of the key issues of air passenger transport law. However, the issue of the reimbursement of expenses paid to third parties for booking flights has received less attention. Nevertheless, service providers, such as travel agencies or online portals, play an increasing role in an expanding aviation sector. The industry has constantly evolved as a result of the liberalisation of the travel market, the inroads made by low-cost carriers and technological developments. As a result of those changes, contact between consumers and airlines is increasingly indirect, also involving intermediary service providers, thus creating a triangular relationship which raises many legal issues in the event of flight cancellations. (3)
19.      While Regulation No 261/2004 expressly provides for reimbursement of the purchase price of the air ticket, namely under Article 8(1)(a) read in conjunction with Article 5(1)(a) of that regulation (‘reimbursement … of the full cost of the ticket at the price at which it was bought’), (4) the question as to whether that price also includes commissions paid by passengers to intermediaries has remained unanswered for a long time. That situation changed with the judgment in Harms, in which the Court recognised the obligation on the air carrier to reimburse such commission. It justified that obligation, in essence, by the fact that the commission collected by an intermediary from a passenger had to be regarded as a ‘component’ of the purchase price of an air ticket. (5) That interpretation is convincing, particularly since the reservation with the intermediary must be regarded as forming part of a single transaction, in which the payment of commission is an essential condition for the purchase of the ticket.
20.      However, the Court made that legal consequence subject to the condition that the various elements of such a ticket, including its price, are ‘authorised’ by the air carrier, since they cannot be ‘set without its knowledge’. (6)
21.      As is apparent from the order for reference, that condition appears to have been understood by several national courts as involving a subjective element, namely the air carrier’s ‘knowledge’ of the intermediary’s commercial activity and, in particular, of the fact that the intermediary charges a commission for the services provided. From a legal point of view, this is a condition which specifically concerns the relationship between the air carrier and ‘its authorised agent’ under Article 2(f) of Regulation No 261/2004.
22.      The questions referred by the national court concern precisely that aspect in so far as they seek, in essence, to establish, first, whether the air carrier must be aware of the exact amount of the commission and, second, who bears the burden of proving that knowledge. I shall examine those questions in the same order.
B.      The first question referred for a preliminary ruling
23.      By its first question, the referring court seeks, in essence, to ascertain whether the price of the ticket which an air carrier is required to reimburse to a passenger includes the commission collected by an intermediary where that air carrier is aware that that intermediary generally charges a commission for its services, but does not know the exact amount in the specific case.
1.      The subjective criterion established by the Court in the judgment in Harms
24.      In that regard, the referring court seeks from the Court a number of clarifications in respect of the judgment in Harms regarding the degree of knowledge required on the part of the air carrier concerning the amount of the commission collected by the intermediary in order for it to be included in the price of the ticket eligible for reimbursement. By its question, the referring court refers to the subjective element, mentioned in my preliminary remarks and regarded by the Court as an essential condition for the air carrier to be required to reimburse the commission, as a component of the purchase price of the ticket, even if that commission corresponds in reality to consideration for a service provided by a third party.
25.      At the outset, it seems to me appropriate to draw attention to the fact that, as follows from a reading of the judgment in Harms, such an obligation depends in the first place on the intention of the air carrier, which, according to the Court, must have ‘authorised’ the various elements of such a ticket, including commission. (7) That interpretation is based on the definition of the term ‘ticket’ in Article 2(f) of Regulation No 261/2004, according to which it is a document giving entitlement to transport, which is not only issued, but also ‘authorised by the air carrier’ or its authorised agent. The Court inferred from this that that authorisation by the carrier extends to the various components of the price of such a ticket. The Court thus considers that the assumption of costs by the air carrier appears justified in that it took a conscious and informed decision which validates the inclusion of that component in the price of the ticket. That is, in any event, what the concept of ‘authorisation’ implies from a semantic point of view. (8) In the judgment in Harms, the fact that that component was not set without the knowledge of the air carrier is, however, treated as an ‘authorisation’, with the result that the carrier’s knowledge that the intermediary has set a commission is sufficient to consider that that carrier has also authorised it.
26.      The judgment in Harms is based, in essence, on the principle that reimbursement of a commission is incumbent on the air carrier where it knowingly uses a third party to carry out its tasks. Consequently, when the Court states that the various elements of the price of a ticket cannot be determined ‘without the knowledge’ of that carrier, that statement must be understood as meaning that that carrier cannot be required to reimburse commissions of which it was unaware and to which, as a result, it did not consent.
27.      Moreover, according to the Court’s interpretation, (9) commission ‘authorised’ by the air carrier which is collected by an intermediary is regarded as ‘unavoidable’, within the meaning of the judgment in Mennens, (10) and must be reimbursed by that carrier. The possibility of purchasing the ticket without the service of an intermediary and thus avoiding the payment of the commission in no way detracts, in my view, from the ‘unavoidable’ nature of that price component. I understand the ‘unavoidable’ nature of the commission paid by the passenger as an essential element of the price of the ticket where the passenger uses an intermediary, which is itself an ‘authorised agent’ of that air carrier. The fact that the passenger accepts an intermediary’s general terms and conditions of sale in order to purchase a ticket and consents to the payment of commission does not change the ‘unavoidable’ nature of that commission either. Unlike optional additional services offered by an intermediary, such as travel insurance, the payment of commission cannot be deselected during the purchase process. It cannot therefore be regarded as ‘separable’ from the price of the ticket within the meaning of the first indent of Article 8(1)(a) of Regulation No 261/2004.
28.      That consideration leads me
to ask how it can be established that the air carrier is aware that the intermediary charges commission when carrying out its business. That aspect is particularly relevant since, in the judgment in Harms, the Court itself admits that there may be situations in which the air carrier is unaware of the commercial practices of intermediaries. It is only in such situations that the passenger’s right to demand reimbursement of the commission from the air carrier is excluded.
29.      Several arguments support a broader understanding of that subjective element in the sense that the stable relationship between the air carrier and the intermediary is sufficient, in principle, to establish the carrier’s awareness and, consequently, its implied consent to the charging of a commission. First of all, it follows from the definition of the term ‘ticket’ in Article 2(f) of Regulation No 261/2004 that it is a document which may be issued or authorised only by the air carrier itself or by ‘its authorised agent’. The fact that each intermediary selling tickets is considered to be an authorised agent of an air carrier justifies the presumption of knowledge and ‘authorisation’ for the purposes of the judgment in Harms, (11) based on the acceptance of the issue of tickets by that agent. It would appear to me to be counter-intuitive to take the view that the air carrier can authorise and accept the sale of a ticket without at the same time accepting the commercial practice of its authorised agent of charging a commission. Such an approach would amount to a form of ‘cherry picking’, allowing the carrier, in the same commercial relationship with its authorised agent, to retain as it pleases what is commercially advantageous to it, while rejecting what is disadvantageous to it. Next, it seems essential to protect the passenger’s trust in the lawfulness of the process for purchasing tickets, especially since he or she is not supposed to know the nature of the commercial relationship between the agent and the air carrier. (12) Nor would it be reasonable to require the passenger to carry out research in that regard. Lastly, when purchasing a ticket from an intermediary, it may legitimately be presumed that the air carrier has authorised the various elements of the ticket price and is therefore, in any event, aware of them.
30.      It should be borne in mind that the air carrier is free to structure its relationship with the intermediary in such a way as to be able to oppose certain commercial practices. Where the air carrier uses a network of intermediaries in its own interest – whether this be in order to expand its customer base or to reduce its administrative costs associated with ticket sales – it can generally be assumed that it is aware of their commercial practices and has therefore ‘authorised’ the charging of a commission within the meaning of Article 2(f) of Regulation No 261/2004. In such a case, it seems legitimate to infer from this that the air carrier has not expressly objected to the charging of commission by the intermediary.
31.      Similarly, where the air carrier chooses to collaborate with a commercial ticket agent, it is reasonable to assume that that carrier wishes, in its own interest, to take advantage of the corresponding marketing opportunities. Therefore, even in the absence of an express contract with the intermediary, by accepting the issue of the ticket by its authorised agent within the meaning of Article 2(f) of Regulation No 261/2004, that carrier authorises it to charge a commission to its customers. Conversely, if the same air carrier wishes to prevent a third party from charging such a commission for reasons relating, for example, to its reputation or its business policy, it must not enter into commercial relations with that third party or must sever them.
32.      The air carrier is therefore exempted from liability only in the exceptional case where the intermediary acts on its own initiative, without any involvement, authorisation or knowledge on the part of that carrier. This includes the situation, referred to in the Commission’s written observations, in which the intermediary offers screen scraping services, (13) its business model being based on the automatic extraction of data on air carriers’ websites without having obtained their consent. The charging of a commission by an intermediary for its agency services in such circumstances cannot be considered to have been ‘authorised’ by the air carrier within the meaning of the case-law.
33.      From that perspective, the authorisation element, established by the Court, appears to be a useful indicator for determining whether there is a sufficient link between the air carrier and the intermediary. Moreover, it is a relatively simple criterion that may be used regardless of the legal nature of their relationship. In so far as the air carrier is free to enter into a commercial relationship with the intermediary of its choice, that carrier cannot rely on its alleged lack of knowledge or passivity in order to evade its responsibility to reimburse the passenger for the commission which the latter has paid to the intermediary. In all cases, the decisive factor is its knowledge of how its trading partner conducts its business, which amounts to an explicit or tacit acceptance of that conduct.
34.      Moreover, it should be borne in mind that, as the Court suggested in the judgment in Harms, the application of the authorisation criterion is an appropriate means of attaining the objectives pursued by Regulation No 261/2004, namely to ensure a high level of protection for passengers and to strike a balance between the interests of passengers and those of air carriers. (14) This is all the more evident when the following aspects of its practical application are taken into account.
35.      The possibility for the passenger to recover the commission by means of the right to reimbursement on the basis provided for by EU law takes account of consumer protection interests, (15) since in such a case the passenger is confronting a single debtor. Otherwise, he or she would be forced to bring legal proceedings both against the air carrier for the price of the ticket and against the intermediary for the commission. Such an approach would not only give rise to additional costs, but would also entail a considerable risk for the passenger, since the legal relationship between the air carrier and the agent may be structured differently depending on the contract and the legal system of the Member State in question. The recognition of a single right to reimbursement based on EU law, namely on Article 8(1)(a) read in conjunction with Article 5(1)(a) of Regulation No 261/2004, (16) thus brings about a significant improvement in his or her legal position.
36.      The use of a criterion defined by EU law and intended to be applied uniformly, such as that developed by the Court in the judgment in Harms, renders irrelevant, in my view, any discussion of the exact nature of the remuneration paid to the intermediary. KLM’s observations in that regard clearly show that the terminology used to classify that cost and its economic distribution vary depending on the legal relationship of the intermediation in question and, sometimes, even within such a relationship, according to the contractual terms applicable between the parties. (17) Legal certainty would be undermined if the relationship between the air carrier and the third party had to be examined each time from an economic and legal perspective in order to determine the components of the price to be reimbursed by the air carrier. Hence the need to identify a criterion that is simple to use, such as the ‘authorisation’ criterion, which applies irrespective of national law.
37.      The subjective criterion established in the case-law in Harms is intended to limit, to a certain extent, the air carrier’s liability in order also to take account of its interests. As I have already stated in this Opinion, the air carrier is liable for the business conduct of its agents only if it has authorised that conduct, even if only tacitly, (18) which must be established in accordance with the rules on the allocation of the burden of proof, which will be examined in the context of the second question referred for a preliminary ruling. That criterion thus prevents any undue extension of the air carrier’s liability to circumstances which are beyond its control.
38.      Moreover, it is important to note that the air carrier does not suffer any disadvantage as a result of assuming liability arising from its commercial relationship with the intermediary, since it has the possibility of bringing a recourse claim against the intermediary. In that regard, it should be recalled that, in the judgment in Airhelp, the Court held that the discharge of obligations by the air carrier pursuant to Regulation No 261/2004 is without prejudice to its rights to seek compensation, under the applicable national law, from any person who caused the air carrier to fail to fulfil its obligations, including third parties, as Article 13 of that regulation provides. According to the Court, that regulation does not make the right to seek compensation conditional on the existence of a contract binding that carrier and the intermediary to which the air passenger had recourse in order to reserve his or her flight. (19)
39.      Although the abovementioned judgment concerns only one specific situation, namely infringement by the intermediary of an obligation incumbent on the air carrier, I consider that Article 13 of Regulation No 261/2004 must be interpreted as also covering other forms of compensation provided for under national law, including recourse claims. (20) From that perspective, that provision enshrines, in my view, the principle that national law supplements that regulation in order to establish a balance of interests between the parties.
2.      The requirement that the air carrier know the precise amount of the commission paid to the intermediary
40.      In the light of those considerations, it is necessary to examine the substantive question referred by the national court as to whether it is necessary, for the purposes of reimbursement under Article 8(1)(a) of Regulation No 261/2004, for the air carrier to have precise knowledge of the amount of the commission charged by the intermediary. As I shall explain below, overly stringent requirements concerning that subjective element would, in my view, give rise to several difficulties.
41.      First, by expressing, in paragraph 20 of the judgment in Harms, the reservation ‘unless that commission was set without the knowledge of the air carrier’, the Court seems to have emphasised only that the air carrier must be unaware of the setting of commission in order to be exempted from reimbursement, without focussing on the lack of knowledge as to its amount. This seems logical to me, as, since the air carrier is generally aware that a commission has been charged, that carrier is in a position to obtain information, from its authorised agent, about the precise amount of that commission. However, making the reimbursement of the commission conditional on a factor such as the carrier’s knowledge of its amount would not guarantee a sufficient degree of predictability for the passenger and would run the risk of undermining his or her confidence in the process for purchasing tickets.
42.      Second, if there was a requirement, for the purposes of reimbursing the passenger, for the air carrier to know the precise amount of the commission charged by the intermediary, that carrier might be tempted to avoid, in bad faith, the reimbursement obligation laid down in Article 8(1)(a) of Regulation No 261/2004 by failing to inform itself of that amount. It could also claim that it was unaware of the intermediary’s commercial practices and, in particular, of the charging of a commission, which would raise difficult questions of proof before the national courts. The question of the truthfulness of those statements would arise in the context of litigation, irrespective of the fact that it is, in my view, perfectly legitimate to require an airline to obtain sufficiently detailed information about the commercial practices of its partners. That aspect, which is relevant from a practical point of view, will be examined in the context of the analysis of the second question referred for a preliminary ruling.
43.      Consequently, if the air carrier is aware of the intermediary’s activities – or possibly even encourages them – requiring it to know the exact amount of the commission charged by the intermediary would ultimately enable it to determine itself the extent to which it is responsible to make the reimbursement under Article 8(1)(a) of Regulation No 261/2004. That provision would then lose part of its meaning in favour of passengers.
44.      Third, requiring the air carrier to have a high level of knowledge of the intermediary’s commercial practices, in particular of the commission charged, may have the effect of leading the passenger to forego the option of using an intermediary and to favour booking directly with the air carrier, despite the more advantageous ticket prices offered by intermediaries. Such a change in passengers’ buying habits could have an economic impact on the activity of intermediaries, even though they play a positive role in the market by diversifying the travel offers to consumers and increasing the customer base of airlines to the benefit of the latter. (21)
45.      Fourth and lastly, to require the air carrier to know the exact amount of the commission would lead, in all likelihood, to exempting it from its obligation to reimburse the passenger for that commission, forcing the passenger to take action against the intermediary in order to obtain reimbursement of that commission by potentially costly procedures. The amount at issue, namely the commission, remains, as the present case shows, rather modest. That would clearly run counter to the objective of ensuring a high level of protection for passengers, set out in recital 1 of Regulation No 261/2004 and of simplifying the procedures for reimbursement put in place by that regulation. For the reasons set out in the preceding points, I consider that, as regards ‘knowledge’ within the meaning of the judgment in Harms, it is sufficient that the air carrier is aware of the intermediary’s role and consents to its activities carried out in return for a commission, without having to know the exact amount of that commission in the specific case.
C.      The second question referred for a preliminary ruling
46.      By its second question for a preliminary ruling, the national court seeks, in essence, to ascertain, with regard to the right to reimbursement under Article 8(1)(a) of Regulation No 261/2004, whether the burden of proving that the air carrier had the necessary knowledge of the agency commission lies with the passenger seeking reimbursement from the air carrier.
47.      If the Court were to answer the first question referred for a preliminary ruling in the way I have proposed, it does not appear necessary to answer the second question in order to resolve the dispute in the main proceedings. In the present case, it is common ground that KLM knew that the intermediary Opodo charged a commission. The intermediation was also part of a collaboration governed by a contract between the defendant and Opodo. Furthermore, it is not disputed that, since it was aware of the intermediary’s business conduct, KLM had, in principle, consented to the payment of a commission.
48.      Since, in the present case, the ‘knowledge’ on the part of the air carrier required by the judgment in Harms is established, it is no longer relevant, in the dispute in the main proceedings, to determine who bears the burden of proof in that regard. Consequently, it is only for the sake of completeness that I shall put forward some thoughts on the allocation of the burden of proof in the context of an ‘ordinary situation’ in which the passenger seeks reimbursement of the price of his or her ticket.
49.      First of all, it should be recalled that it is in accordance with the procedures laid down by national law that passengers and air carriers must assert their rights to seek legal redress before the courts of the Member States, as is clear inter alia from recital 22 of Regulation No 261/2004. The rules on the burden of proof in matters of civil liability are in principle governed by those national procedures.
50.      By way of derogation from that principle, Regulation No 261/2004 lays down a series of provisions expressly concerning the burden of proof in order to ensure that the rights of passengers are respected. That is the case, in particular, with the provisions referred to in Article 5(3) and (4) of that regulation, which make the air carrier subject to certain obligations in the event of cancellation of a flight and also impose on it the burden of proving compliance with those obligations. In addition, rules relating to the allocation of the burden of proof may also be inferred by interpreting provisions of that regulation, which has moreover been confirmed by the case-law.
51.      Thus, in that regard, the Court has already held that the responsibility of offering and organising re-routing under Article 8(1)(b) of Regulation No 261/2004, a responsibility borne by the air carrier concerned, entails the burden of proving that the re-routing thus organised was performed at the earliest opportunity. (22) In the light of those considerations, and in the absence of any express provision in that regulation or any formal clarification by the Court in the judgment in Harms, the relevant provisions of that regulation require interpretation.
52.      In that context, it should be recalled that Article 8(1)(a) of Regulation No 261/2004 imposes on the air carrier the obligation to reimburse the price of the ticket, irrespective of the reason for the cancellation of the flight. Unlike the obligation to compensate passengers under Article 7 of that regulation, there is no exception to the reimbursement obligation that relates to the existence of extraordinary circumstances. (23) Thus, the reimbursement obligation appears to be more extensive than the obligation to compensate passengers. From that perspective, the responsibility of the air carrier to reimburse the ticket at the price at which it was purchased also entails, in my opinion, the burden of proving that, where appropriate, certain elements of that price should not be reimbursed.
53.      That conclusion is all the more convincing in that it should be recalled that the intermediary acts as the authorised agent of an air carrier, which justifies a presumption of awareness of that agent’s commercial practices. (24) The air carrier is the most knowledgeable of the practices of its intermediaries. As I have indicated in this Opinion, (25) the air carrier is also best placed to object to their practice in respect of commission and, therefore, is presumed to have consented to such commission being charged to passengers, whereas the passengers cannot exercise any influence in that regard. (26) However, it is clear that placing the burden of proof on the passenger would entail considerable difficulties for him or her, which would not serve the objective of ensuring a high level of protection for passengers.
54.      Lastly, the judgment in Harms seems to me to provide some guidance in favour of an interpretation according to which the burden of proof lies with the air carrier. The Court held that, unless the air carrier did not have the necessary knowledge of it, the commission charged by an intermediary falls within the obligation to pay compensation incumbent on that air carrier under the combined provisions of Article 8(1)(a) and Article 5(1) of Regulation No 261/2004. Consequently, it may be inferred that the air carrier’s lack of knowledge of the commission constitutes an exception to the rule. By introducing that relationship between the rule and the exception, the Court implicitly established a rule on the burden of proof in accordance with which it is for the air carrier to prove that it did not have the necessary knowledge of the intermediary’s activities and that it had not consented to the pursuit of such activities in return for a commission. (27)
55.      That said, I am not unsympathetic to the argument put forward by the Commission that it is necessary to avoid apportioning the burden of proof to the detriment of the air carrier in so far as such allocation would require it to prove the non-existence of a fact. (28) In such a case, the air carrier would be required to prove a ‘negative fact’, which is impossible in practice, (29) especially since that would involve its ‘forum internum’. In order to avoid such an undesirable consequence and to take adequate account of the interests of the air carrier, the requirements relating to the reversal of the burden of proof should not be too strict.
56.      For that reason, I consider, like the Commission, that air carriers already discharge the burden of proof in that they prove, by credibly setting out all the relevant contextual circumstances, that they had no knowledge of, and did not consent to, the charging of commission by the intermediary in the course of its business. If that were the case, it would be for the passenger to demonstrate, with reasons, that the collaboration between the air carrier and the intermediary was designed in such a way that the carrier should have been aware that a commission would be charged when its tickets were sold by the intermediary and that it had consented to this.
57.      In my view, that interpretation best reflects the objective of striking a balance between the interests of air passengers and those of air carriers which the EU legislature intended to pursue by adopting Regulation No 261/2004. (30) I therefore propose that the answer to be given to the referring court should be that, in order to be exempted from the obligation to reimburse the commission concerned, it is for the air carrier to prove that it had no knowledge of and had not consented to the charging of commission by the intermediary when carrying out its business. The air carrier already discharges the burden of proof by credibly setting out all relevant contextual circumstances.
VI.    Conclusion
58.      In the light of all the foregoing considerations, I propose that the Court of Justice should answer the questions referred by the Oberster Gerichtshof (Supreme Court, Austria) as follows:
Article 8(1)(a) read in conjunction with Article 5(1)(a) of Regulation (EC) No 261/2004 of the European Parliament and of the Council of 11 February 2004 establishing common rules on compensation and assistance to passengers in the event of denied boarding and of cancellation or long delay of flights, and repealing Regulation (EEC) No 295/91,
must be interpreted as meaning that:
–        the price of the ticket to be taken into consideration for the purpose of determining the reimbursement owed by the air carrier to a passenger in the event of cancellation of a flight also includes the difference between the amount paid by the passenger and the amount received by the air carrier, which corresponds to a commission collected by a person acting as an intermediary between those two parties, without the air carrier being required to know the exact amount of that commission;
–        in order to be exempted from the obligation to reimburse the abovementioned commission, it is for the air carrier to prove that it had no knowledge of and had not consented to the charging of commission by the intermediary when carrying out its business. The air carrier already discharges the burden of proof by credibly setting out all relevant contextual circumstances.
1      Original language: French.
2      OJ 2004 L 46, p. 1.
3      See judgment of 21 December 2021, Airhelp (C‑263/20, EU:C:2021:1039) concerning the obligations imposed on the air carrier by Regulation No 261/2004 when the contract for carriage has been entered into through an online booking platform.
4      Emphasis added.
5      See judgment in Harms, paragraph 16.
6      See judgment in Harms, paragraph 17.
7      Judgment in Harms, paragraph 17.
8      That understanding underpins all the language versions of the judgment that I consulted as part of my analysis. See the Spanish (‘deben haber sido autorizados’), Danish (‘skal være autoriseret’), German (‘genehmigt werden müssen’), English (‘must … be authorised’), Italian (‘devono … essere … autorizzato’), Lithuanian (‘turi būti gautas jo sutikimas’), Dutch (‘worden toegestaan’) and Portuguese (‘devem … ser autorizados’) language versions.
9      Judgment in Harms, paragraph 18.
10      Judgment of 22 June 2016, Mennens (C‑255/15, EU:C:2016:472, paragraph 36). In that judgment, the Court held that the reimbursement of a part of the ‘price of the ticket’ provided for in Article 10(2)(a) to (c) of Regulation No 261/2004, in the event that the air carrier places a passenger in a class lower than that for which the ticket was purchased, must be determined by reference to solely ‘unavoidable’ components of that price, in the sense that it is necessary to pay them in order to avail of the service proposed by the air carrier in return.
11      Judgment in Harms, paragraph 17.
12      See Dejonckheere, J., ‘Reimbursement of commissions charged by intermediaries after flight cancellation. A legal analysis of the Harms Case (C‑601/17) and its impact on the objectives of Regulation (EC) No 261/2004’, Air & Space Law, Vol. 44, Issue
1, 2019,
p. 114. That author wonders how the passenger is supposed to know what percentage of the ticket price is passed on to the airline and whether the airline knows the amount of the commission set by the intermediary.
13      See judgment of 15 January 2015, Ryanair (C‑30/14, EU:C:2015:10, paragraph 16).
14      See judgment in Harms, paragraph 15.
15      The need to take full account of the requirements of consumer protection in the field of air transport is recognised in recital 1 of Regulation No 261/2004.
16      See point 19 of this Opinion.
17      In any event, for the purposes of this Opinion, the distinction drawn by KLM in its observations between an ‘agency commission’ payable by the carrier and ‘arrangement fees’ payable by the passenger has no legal significance. The present case concerns only the reimbursement of the amount collected by the intermediary from a passenger, in a factual situation identical to that which gave rise to the judgment in Harms.
18      See points 26 and 33 of this Opinion.
19      See judgment of 21 December 2021, Airhelp (C‑263/20, EU:C:2021:1039, paragraphs 54 and 55).
20      See, to that effect, Maruhn, J.,
BeckOK Fluggastrechte-Verordnung (Ronald Schmidt), 33rd ed., Munich, 2025, Article 13(1) et seq., who considers that Article 13 of Regulation No 261/2004 does not limit the air carrier’s right of recourse. According to the author, that provision does not in itself establish a right of recourse, but presupposes it. Such recourse may arise either from the underlying contract or from principles of business management (‘negotiorum gestio’).
21      See Seyffert, W., Conradt, L., Laib, S., ‘Flugbuchung über Dritte – warum Online-Reiseportale unter dem (Haftungs)-Radar fliegen’, Neue Zeitschrift für Verkehrsrecht, No 11, 2021, p. 563. Those authors state that the use of online portals is in the consumer’s interest in order to be able to compare flight offers more easily, but the airlines also benefit from it.
22      Judgment of 29 July 2019, Rusu (C‑354/18, EU:C:2019:637, paragraph 61).
23      See judgment of 8 June 2023, Austrian Airlines (Repatriation flight) (C‑49/22, EU:C:2023:454, paragraph 45).
24      See point 29 of this Opinion.
25      See point 30 of this Opinion.
26      See point 27 of this Opinion.
27      See, to that effect, Degott, P., Schmidt, R.,
BeckOK Fluggastrechte-Verordnung, C.H. Beck, 33rd ed., Munich, 2025, Article 8(4b).
28      See Dejonckheere, J., ‘Reimbursement of commissions charged by intermediaries after flight cancellation. A legal analysis of the Harms Case (C‑601/17) and its impact on the objectives of Regulation (EC) No 261/2004’, Air & Space Law, Vol. 44, Issue 1,
2019,
p. 114, op. cit.. That author points to the difficulties of an equitable apportionment of the burden of proof. First, the author believes that the burden of proof should not be borne by the passenger. Secondly, he considers that a legal presumption that the air carrier was aware of the commission would be unduly detrimental to the interests of the airlines.
29      As the Court has consistently held, the rules of EU law do not require a person to prove a negative (see judgments of 24 March 1988, Commission v Italy (104/86, EU:C:1988:171, paragraph 11), and of 4 July 2024, EUIPO v KD (C‑5/23 P, EU:C:2024:575, paragraph 47)).
30      See judgments of 19 November 2009, Sturgeon and Others (C‑402/07 and C‑432/07, EU:C:2009:716, paragraph 67), and of 22 April 2021, Austrian Airlines (C‑826/19, EU:C:2021:318, paragraph 39).