Advocate General’s Opinion in Case C-627/24 P
The Court of Justice of the European Union (CJEU) is dealing in Case C-627/24 P with ByteDance’s appeal against its classification as a gatekeeper under the Digital Markets Act. Advocate General Andrea Biondi proposed in his Opinion of 15 October 2026 that the appeal be dismissed. The Opinion was published as Press Release No 151/26 of the Court of Justice.
The proceedings concern the designation of ByteDance as a gatekeeper for TikTok. The European Commission had adopted the relevant decision on 5 September 2023 and classified TikTok as an online social networking service. ByteDance challenged that designation but was unsuccessful before the General Court of the European Union (General Court). ByteDance lodged an appeal on 26 September 2024 against the judgment of the General Court of 17 July 2024 in Case T-1077/23.
The decision of the Court of Justice is still pending. Opinions of Advocates General do not bind the Court of Justice, but they regularly carry weight for the legal assessment of the issues raised.
Background to the Gatekeeper Designation under the DMA
Commission Decision of 5 September 2023
In September 2023, the Commission designated ByteDance as a gatekeeper within the meaning of the Digital Markets Act. In its assessment, the company met the relevant quantitative thresholds. ByteDance, by contrast, argued that the statutory presumptions had been rebutted.
The Commission did not follow that view and adopted the designation decision without conducting a market investigation. The General Court of the European Union dismissed the action brought against it in July 2024. The proceedings at first instance were conducted under the expedited procedure; the appeal proceedings before the Court of Justice were also dealt with on an expedited basis.
The hearing in Case C-627/24 P took place before the Grand Chamber of the Court of Justice on 12 May 2026.
ByteDance’s Forms of Order Sought in the Appeal Proceedings
In its appeal, ByteDance seeks in particular:
- the setting aside of the judgment of the General Court of the European Union,
- the annulment of the Commission’s designation decision,
- an order that the Commission bear the costs of both instances.
The appeal is directed against the General Court’s confirmation of the gatekeeper designation. According to the available information, Advocate General Biondi does not examine the entire appeal, but only selected parts of it. His Opinion concerns the first and third parts of the first ground of appeal, which consists of five parts, the second ground of appeal concerning the right to be heard, and an application by the Commission for substitution of part of the General Court’s reasoning.
Standard for Rebutting the Gatekeeper Presumptions
Mere Doubts Are Not Sufficient
A central point of the Opinion concerns the question of when the Commission must open a market investigation if an undertaking challenges its designation as a gatekeeper. In the Advocate General’s view, it is not sufficient merely to raise doubts about the statutory presumptions.
Rather, the undertaking concerned must put forward sufficiently convincing arguments that seriously call those presumptions into question. However, it does not have to prove conclusively at that stage that it is not a gatekeeper.
The Advocate General thus distinguishes between two scenarios: if the arguments put forward are not sufficiently robust, the Commission may reject them without a further market investigation. If, however, they manifestly call the presumptions into question, the Commission, in his view, has no discretion but must open a market investigation. According to the Advocate General’s account, this applies unless it is clear that the undertaking does not meet the qualitative requirements.
Significance of Article 3 DMA
In its appeal, ByteDance alleges, among other things, an infringement of Article 3(1)(a) and Article 3(5) DMA. According to the company’s argument, the General Court effectively rendered the quantitative presumptions irrebuttable. In addition, the necessary connection between market capitalisation and the monetisable potential of users in the European Union was not sufficiently taken into account.
According to the published Opinion, the Advocate General does not accept that line of argument in a manner that would lead to the judgment being set aside. Instead, he recommends that the Court of Justice dismiss the appeal in its entirety, insofar as the points examined by him are concerned.
TikTok as an Important Gateway
Classification as a Social Networking Service
The Commission classified TikTok as an online social networking service. On that basis, ByteDance was designated as a gatekeeper for TikTok. This classification is of considerable importance for the application of the Digital Markets Act, because gatekeepers are subject to far-reaching conduct and transparency obligations.
The obligations under the DMA include, among other things, requirements concerning the use and combination of data, the treatment of a gatekeeper’s own services in rankings, the uninstallability of pre-installed applications, and data access for business users. In the event of infringements, substantial fines may be imposed, calculated by reference to worldwide annual turnover.
Multi-Homing Does Not, in the Advocate General’s View, Disprove the Gateway Function
ByteDance had argued that TikTok does not function as an important gateway for business users. In support of this, it referred, among other things, to the fact that users also use competing social networks. It also argued that TikTok is smaller than other platforms and does not have a comprehensive ecosystem.
In the Advocate General’s view, the fact that users simultaneously use other services such as Instagram or Facebook is not capable of disproving TikTok’s classification as an important gateway. So-called multi-homing does not preclude such a function.
The Opinion also refers to findings made by the Commission. According to those findings, the Commission stated in the designation decision, among other things, that ByteDance operates its own ecosystem encompassing video editing services, enterprise software, advertising, news and health applications.
Right to Be Heard and the General Court’s Reasoning
No Obligation to Conduct a Second Hearing before the Decision
A further focal point concerns ByteDance’s right to be heard. The General Court of the European Union had found an infringement in that respect. Advocate General Biondi considers that assessment to be vitiated by an error of law.
In his view, ByteDance did have the right to submit objections to the designation. The Commission also had to examine those objections carefully. However, in the Advocate General’s view, it was not obliged to give ByteDance an additional opportunity, before adopting the designation decision, to comment on its preliminary assessment.
The DMA provides that the Commission must designate an undertaking no later than 45 working days after receipt of the notification. Within that period, according to the Advocate General’s assessment, the Commission did not owe ByteDance a second hearing.
Substitution of Grounds with the Outcome Unchanged
The Advocate General therefore proposes that the Court of Justice substitute the General Court’s reasoning on this point. However, according to his proposal, the outcome dismissing the action should remain in place.
Accordingly, if the Court of Justice follows the Opinion, it would not decide in favour of ByteDance on the basis of the hearing-related error assumed by the General Court. Rather, the dismissal of the action would be upheld in its result, albeit with amended reasoning concerning the right to be heard.
Significance for Companies in the Digital Single Market
First Consideration of the DMA by the Court of Justice
Case C-627/24 P is of particular significance because it is the first time the Court of Justice has heard issues relating to the Digital Markets Act. The Opinion may therefore provide guidance for the interpretation of the DMA beyond the specific case.
The focus is, in particular, on the question of what requirements are to be imposed on undertakings seeking to rebut the statutory gatekeeper presumptions. Under the Advocate General’s approach, undertakings must put forward more than general doubts. At the same time, he does not require full proof to the contrary already at this stage.
Relationship to Further Gatekeeper Designations
In addition to ByteDance, Alphabet, Meta Platforms, Apple, Amazon, Microsoft and Booking.com, among others, have been designated as gatekeepers. The application of the DMA therefore affects a number of central digital services and platforms.
Further proceedings may also be influenced by the interpretation of the requirements for designation, rebuttal and market investigation. According to the available information, in June 2026 the General Court partially annulled Meta’s designation, relying in doing so on the ByteDance judgment. This development shows that the legal clarification of the DMA requirements is of considerable practical relevance for platform companies and their business users.
At the same time, it should be noted that no judgment of the Court of Justice has yet been delivered in the present proceedings. The Opinion reflects the view of the Advocate General; the final decision remains reserved to the Court of Justice.
Assessment by MTR Legal Rechtsanwälte
The Opinion in Case C-627/24 P makes clear that classification as a gatekeeper under the DMA cannot be considered solely on the basis of formal thresholds. What is also decisive is the level of requirements to be imposed for rebutting the statutory presumptions and when a market investigation must mandatorily be opened.
For companies with digital business models, platform structures or data-based services, the further development of the proceedings may be of considerable importance. Legal questions concerning the classification of digital services, obligations under the DMA or related areas of IT law may require a careful review of the respective business model. MTR Legal Rechtsanwälte supports clients with corresponding issues as part of its legal advice in IT law.
