Opinion of the Advocate General — ECLI:EU:C:2024:470
Date: 2024-06-06
Language of the case: Dutch
Procedure: Reference for a preliminary ruling
Origin: Netherlands

Summary C-264/23 – 1 
Case C-264/23 
Summary of the request for a preliminary ruling pursuant to Article 98(1) of 
the Rules of Procedure of the Court of Justice 
Date lodged: 
24 April 2023 
Referring court:  
Rechtbank Amsterdam (Netherlands) 
Date of the decision to refer:  
22 February 2023 
Applicants:  
Booking.com BV 
Booking.com (Deutschland) GmbH 
Defendants:  
25hours Hotel Company Berlin GmbH 
Aletto Kudamm GmbH 
Air-Hotel Wartburg Tagungs- & Sporthotel GmbH 
Andel’s Berlin Hotelbetriebs GmbH 
Angleterre Hotel GmbH & Co. KG 
Atrium Hotelgesellschaft mbH 
Azimut Hotelbetrieb Köln GmbH & Co. KG 
Barcelo Cologne GmbH 
Business Hotels GmbH 
Cocoon München GmbH 
DJC Operations GmbH 
Dorint GmbH 
EN 
SUMMARY OF THE REQUEST FOR A PRELIMINARY RULING – CASE C-264/23 
 
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Eleazar Novum GmbH 
Empire Riverside Hotel GmbH & Co. KG 
Explorer Hotel Fischen GmbH & Co. KG 
Explorer Hotel Nesselwang GmbH & Co. KG 
Explorer Hotel Schönau GmbH & Co. KG 
Fleming’s Hotel Management und Servicegesellschaft mbH & Co. 
KG 
G. Stürzer GmbH Hotelbetriebe 
Hotel Bellevue Dresden Betriebs GmbH 
Hotel Europäischer Hof W.A.L. Berk GmbH & Co KG 
Hotel Hafen Hamburg. Wilhelm Bartels GmbH & Co. KG 
Hotel John F GmbH 
Hotel Obermühle GmbH 
Hotel Onyx GmbH 
Hotel Rubin GmbH 
Hotel Victoria Betriebs- und Verwaltungs GmbH 
Hotel Wallis GmbH 
i31 Hotel GmbH 
IntercityHotel GmbH 
ISA Group GmbH 
Kur-Cafe Hotel Allgäu GmbH 
Lindner Hotels AG 
M Privathotels GmbH & Co. KG 
Maritim Hotelgesellschaft mbH 
MEININGER Shared Services GmbH 
Oranien Hotelbetriebs GmbH 
BOOKING.COM AND BOOKING.COM (DEUTSCHLAND) 
 
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Platzl Hotel Inselkammer KG 
prize Deutschland GmbH 
Relexa Hotel GmbH 
SANA BERLIN HOTEL GmbH 
SavFra Hotelbesitz GmbH 
Scandic Hotels Deutschland GmbH 
Schlossgarten Hotelgesellschaft mbH 
Seaside Hotels GmbH & Co. KG 
SHK Hotel Betriebsgesellschaft mbH 
Steigenberger Hotels GmbH 
Sunflower Management GmbH & Co. KG 
The Mandala Hotel GmbH 
The Mandala Suites GmbH 
THR Hotel am Alexanderplatz Berlin Betriebs- und Management 
GmbH 
THR III Berlin Prager-Platz Hotelbetriebs- und 
Beteiligungsgesellschaft mbH 
THR München Konferenz und Event Hotelbetriebs- und 
Management GmbH 
THR Rhein/Main Hotelbetriebs- und Beteiligungs-GmbH 
THR XI Berlin Hotelbetriebs- und Beteiligungsgesellschaft mbH 
THR XXX Hotelbetriebs- und Beteiligungs-GmbH 
Upstalsboom Hotel + Freizeit GmbH & Co. KG 
VI VADI HOTEL Betriebsgesellschaft mbH & Co. KG 
Weissbach Hotelbetriebsgesellschaft mbH 
Wickenhäuser & Egger AG 
Wikingerhof GmbH & Co. KG 
SUMMARY OF THE REQUEST FOR A PRELIMINARY RULING – CASE C-264/23 
 
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Hans-Hermann Geiling, Hotel Präsident 
Karl Herfurtner, Hotel Stadt München e.K. 
  
Subject matter of the main proceedings 
The applicants seek a declaratory judgment that they have not acted unlawfully in 
applying the parity clauses used by them. The defendants seek a declaratory 
judgment that the applicants infringed European competition law by using those 
parity clauses. 
Subject matter and legal basis of the request 
In its questions referred for a preliminary ruling under Article 267 TFEU on parity 
clauses in the context of Article 101(1) TFEU, the referring court asks, in 
particular, whether those clauses are to be regarded as an ancillary restriction or 
whether they constitute a significant infringement of that article. In the latter case, 
the referring court considers it necessary to obtain guidance on interpretation in 
order to determine the relevant market for transactions mediated by online hotel 
platform services in the context of the possible application of Commission 
Regulation (EU) No 330/2010 of 20 April 2010 on the application of 
Article 101(3) of the Treaty on the Functioning of the European Union to 
categories of vertical agreements and concerted practices (OJ 2010 L 102, p. 1). 
Questions referred for a preliminary ruling 
1. Do wide and narrow parity clauses constitute an ancillary restriction in the 
context of Article 101(1) TFEU? 
2. If Regulation (EU) No 330/2010 applies, how should the relevant market be 
defined when transactions are mediated by an online travel agency platform 
(OTA) on which accommodation establishments can offer rooms and get in touch 
with travellers who can book a room through the platform? 
Provisions of European Union law cited 
FEU Treaty, Article 101(1) and (3) 
Commission Regulation (EU) No 330/2010 of 20 April 2010 on the application of 
Article 101(3) of the Treaty on the Functioning of the European Union to 
categories of vertical agreements and concerted practices (OJ 2010 L 102, p. 1). 
BOOKING.COM AND BOOKING.COM (DEUTSCHLAND) 
 
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Regulation (EU) 2022/1925 of the European Parliament and of the Council of 
14 September 2022 on contestable and fair markets in the digital sector and 
amending Directives (EU) 2019/1937 and (EU) 2020/1828 (Digital Markets Act) 
(OJ 2022 L 265, p. 1) 
Commission Notice of 9 December 1997 on the definition of relevant market for 
the purposes of Community competition law (OJ 1997 C 372, p. 5) 
Commission Staff Working Document of 8 September 2020 on Evaluation of the 
Vertical Block Exemption Regulation, SWD (2020) 172 final 
Succinct presentation of the facts and procedure in the main proceedings 
1 Booking.com BV operates an online accommodation-booking platform and is 
supported in its activities by, inter alia, Booking.com Deutschland (together, ‘the 
applicants’). The applicants do not determine which rooms are offered on the 
platform or at what price, these being matters determined by the accommodation 
establishments themselves. On the applicants’ platform travellers can search for, 
compare and book accommodation. The applicants also provide additional 
services, including a customer service and a review system. The platform is free 
of charge for travellers and is of interest to accommodation establishments due to 
the (indirect) network effects, in particular as the number of travellers using the 
platform increases. 
2 Accommodation establishments, including those offered by the defendants – 
companies under German law which own or operate hotels – pay a commission to 
the applicants when travellers book accommodation and do not subsequently 
cancel. In addition to the platform, accommodation establishments can use 
alternative online and offline sales channels to advertise their rooms (so-called 
‘multi-homing’). 
3 Until 1 July 2015, the applicants included a ‘wide parity clause’ in agreements 
concluded with accommodation establishments. Under that wide parity clause, 
accommodation establishments were not allowed to offer rooms on their own 
sales channels or on sales channels operated by third parties at a price lower than 
that offered on the applicants’ platform. 
4 In a case brought against another online hotel platform, the Bundeskartellamt 
(German Federal Cartel Office), by decision of 20 December 2013, held that a 
wide parity clause similar to that used by the applicants was contrary to the 
prohibition of anti-competitive agreements under both EU and German law and 
issued an injunction prohibiting its use. That decision was upheld on appeal by the 
Oberlandesgericht Düsseldorf (Higher Regional Court, Düsseldorf, Germany). 
5 On 1 July 2015, the applicants, in consultation with the French, Italian and 
Swedish competition authorities, replaced the wide parity clause with a narrow 
parity clause (together, ‘the parity clauses’). Under the narrow parity clause, 
SUMMARY OF THE REQUEST FOR A PRELIMINARY RULING – CASE C-264/23 
 
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accommodation establishments were not allowed to offer rooms on their own 
sales channels at a price lower than that offered on the applicants’ platform. This 
narrow parity clause was included in the agreements concluded with 
accommodation establishments up to 1 February 2016. 
6 By decision of 22 December 2015, the German Federal Cartel Office held that the 
applicants’ narrow parity clause was contrary to EU and German competition law 
and issued an injunction prohibiting its use. 
7 The applicants appealed against that decision to the Higher Regional Court, 
Düsseldorf, which, in its decision of 4 June 2019, held, inter alia, that the narrow 
parity clause, while restricting competition, was necessary in order to ensure fair 
compensation for the services provided by the applicants. The Higher Regional 
Court, Düsseldorf, accordingly held that the narrow parity clause was not contrary 
to the prohibition of anti-competitive agreements under German and EU law and 
subsequently set aside the German Federal Cartel Office’s injunction. 
8 Hearing an appeal on a point of law, the Bundesgerichtshof (Federal Court of 
Justice, Germany) held, by order of 18 May 2021, that the narrow parity clause 
appreciably restricts competition between hotel platforms on the market for hotel 
platform services and between hotels on the market for hotel rooms. The Federal 
Court of Justice also stated that the narrow parity clause cannot be classified as an 
ancillary restriction and is not exempt under Regulation (EU) No 330/2010 or the 
statutory exemption from the prohibition of anti-competitive agreements under 
EU or German law. 
9 Furthermore, a collective action was also brought in 2020 by a large number of 
German accommodation establishments (not the defendants), seeking 
compensation for the hotels concerned in respect of the damage that they claim to 
have suffered as a result of the parity clauses and abuse of a dominant position by 
the applicants (‘the daBeisein initiative’). By summons dated 31 March 2021, the 
applicants brought proceedings before the Landgericht Berlin (Regional Court, 
Berlin, Germany) against the accommodation establishments affiliated to the 
daBeisein initiative. Those proceedings are pending at the time when the present 
request for a preliminary ruling is made. 
10 By the main proceedings before the Netherlands referring court, the applicants 
seek a declaratory judgment that they did not act unlawfully in applying the parity 
clauses. By contrast, the defendants seek a declaratory judgment that the 
applicants infringed Article 101(1) TFEU by using those parity clauses and 
consequently acted unlawfully. 
BOOKING.COM AND BOOKING.COM (DEUTSCHLAND) 
 
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The essential arguments of the parties in the main proceedings 
Ancillary restriction 
11 The applicants argue that the parity clauses constitute an ancillary restriction, 
since the agreements concluded between them and the accommodation 
establishments have positive or neutral effects on competition and those clauses 
are inherent in and necessary for the provision of services. 
12 The applicants argue that the parity clauses were introduced to prevent unfair, 
unpaid use of their online booking platform services (so-called ‘free-riding’). In 
the absence of such clauses, they contend, travellers and accommodation 
establishments could benefit from the applicants’ investments in search and 
comparison functions, while the applicants would not be able to recoup those 
investments. 
13 The defendants dispute the ancillary nature of the parity clauses. They argue that 
the narrow parity clause is not indispensable, as its abolition in 2016 had no 
appreciable adverse effect on the applicants’ activities. In addition, they rely on 
the fact that the applicants fail to demonstrate that there are not any less intrusive 
ways to counter free-riding. 
Definition of the market 
14 According to the applicants, the relevant market is the market for the booking and 
distribution of travel accommodation. They stress that the online booking platform 
is a two-sided platform, where, for both hotels and travellers, the different online 
and offline distribution channels are substitutable and therefore constitute one and 
the same market. 
15 The defendants argue that there is a separate (German) market for the services of 
online hotel platforms, as only these platforms offer the combination of searching, 
comparing and booking. Consequently, they argue, online distribution of hotel 
rooms cannot be substituted by offline distribution. 
Succinct presentation of the reasoning in the request for a preliminary ruling 
Question 1 
16 The referring court states that it is not only the applicants and defendants who 
disagree as to whether a parity clause is excluded from the scope of Article 101(1) 
TFEU as an ancillary restriction, as can be seen in the decisions of the German 
Federal Cartel Office, the Higher Regional Court and the Federal Court of Justice 
on parity clauses. 
SUMMARY OF THE REQUEST FOR A PRELIMINARY RULING – CASE C-264/23 
 
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17 The referring court further points out that both wide and narrow parity clauses are 
now prohibited by law in Belgium, France, Italy and Austria and refers to the case 
currently pending before the Regional Court, Berlin, which raises the same issue. 
The answer to the first question is thus necessary to avoid contradictory decisions 
within the European Union. 
Question 2 
18 The referring court takes the view that, in the light of developments in European 
competition law, there is a lack of clarity as to how the market for online hotel 
platform services should be defined. 
19 According to the referring court, it is clear from the Commission Notice of 
9 December 1997 on the definition of the relevant market for the purposes of 
Community competition law that demand substitutability is important in 
determining the relevant market for a given product. Although the specific product 
functionalities of online hotel platforms – referred to by the defendants as 
‘searching, comparing and booking’ – provide guidance in determining the 
relevant market, they are not sufficient to define that market. 
20 The referring court also notes the dual nature of the defendants’ arguments. On the 
one hand, the defendants take the position that the sales channel through their own 
hotel websites belongs to a different market, and on the other hand, they argue that 
the parity clause eliminates ‘horizontal competition’ between online distribution 
by the applicants’ platform and direct distribution by the hotels themselves. 
According to the referring court, it follows from the latter that hotels face 
competitive pressure from the applicants’ platform via their own websites and that 
the market is broader than that of online hotel platform services. It also relies, in 
this regard, on a decision of the European Commission of 30 May 2011 on the 
existence of a single market for the online distribution of air tickets via online 
platforms and airlines’ own websites (COMP/M.6163, C(2011) 3913, 
paragraph 25). 
21 In addition, the referring court refers to recent developments in European 
competition law which may have an impact on the definition of the market. The 
Commission Notice of 9 December 1997 on the definition of the relevant market 
for the purposes of Community competition law is to be reviewed by the 
European Commission, in the context of which a working document has already 
been published (Commission Staff Working Document of 8 September 2020, 
Evaluation of the Vertical Block Exemption Regulation, SWD (2020) 172 final). 
According to the referring court, the content of that working document leans 
towards the view that there should be less emphasis on defining the market and 
more on identifying the competitive pressure experienced from various sides. This 
also shows that there is wider support for the applicants’ call for a different 
approach to their position as a two-sided platform. The referring court also cites 
Regulation (EU) 2022/1925 on the regulation of digital platforms, a recent 
regulation which seeks to regulate the market conduct of the largest undertakings 
BOOKING.COM AND BOOKING.COM (DEUTSCHLAND) 
 
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providing core platform services where previous options to do so were 
insufficient. 
The referring court takes the view that, in the light of the abovementioned 
developments in European competition law, there is a lack of clarity as to the 
manner in which the market is defined in the context of Article 101(1) TFEU.