Arcom calls for the strengthening of the effectiveness of the advertising registers provided for in the Digital Services Regulation (DSR)

The European Digital Services Act (DSA) aims to hold online platforms accountable by imposing a set of obligations on them regarding the fight against unlawful content and the transparency of their features.

Article 39 of the regulation requires very large platforms and very large search engines (TikTok, Facebook, Instagram, X, Google, YouTube, Amazon, etc.) to make information relating to adverts shown on their services available to the public via online registers.

These registers must enable public authorities, researchers, journalists, civil society organisations and, more broadly, the public to analyse online advertising campaigns, identify the online advertising operators funding them and gain a better understanding of the logic behind targeting and diffusion. They are an essential tool for ensuring transparency in the operation of digital services.

Advertising revenue is the main source of income in the business model of many platforms and search engines. In France, the digital advertising market is estimated to be worth 12.4 billion euros in 2025 by the Observatoire de l’e-pub. In this context, transparency regarding the diffusion of online advertising is a tangible issue for everyone: these registers can, for example, help to better understand who is funding certain campaigns and their targets, or to identify adverts that may contribute to the manipulation of information, misleading commercial practices, the promotion of health-related products, or environmental claims.

Arcom, the French authority responsible for ensuring compliance with the European Digital Services Act, has carried out an analysis of the implementation of advertising registers. It is today publishing the key findings.

Useful registers, but still too varied

Arcom’s analysis, as of discussions with users of the registers and internal observations, confirms the value of the principle behind such a scheme.

However, it highlights recurring difficulties that continue to limit their practical effectiveness: access conditions that are sometimes complex, uneven search functionality, data that is insufficiently comprehensive or legible, constraints on the use of public application programming interfaces (APIs) and a lack of harmonisation between registers.

Arcom summons clarification at European level

Arcom has submitted to the European Commission – which is responsible for overseeing the obligations of very large online platforms (with more than 45 million unique users per month within the European Union) – a detailed memorandum setting out the feedback gathered from users of advertising registers, as well as analyses of the practical conditions regarding the accessibility, availability and usability of these registers.

Arcom considers that future guidelines issued by the European Commission (as provided for in Article 39 of the RSN) concerning the conditions of access to registers and APIs, the minimum functionality for multi-criteria searches, the technical documentation required, the quality and accuracy of the information to be provided, and the harmonisation of data formats, could usefully clarify expectations regarding the structure, organisation and functionalities of advertising registers.

Furthermore, Arcom highlights the value of standardisation work at European level (Article 44 of the RSN), which would strengthen the interoperability of advertising registers and facilitate their use by public bodies, researchers and civil society.

Feedback from users of advertising registers

Public authorities, researchers, journalists, civil society organisations and, more broadly, users of advertising registers may send Arcom, at professionnels-dsa@arcom.fr, to share their feedback on access conditions, the functioning or usability of the registers, in order to assist in monitoring the implementation of Article 39 of the RSN.