In short. DSA Article 26 requires disclosures on covered online platforms, while Article 39 requires ad repositories for designated very large platforms and search engines.
Definition: Articles 26 and 39 of the Digital Services Act (DSA) provide for individual ad disclosures and public advertising repositories. Their application to an AI search interface depends on the service's legal classification, exemptions and, for repository duties, designation as a very large service.
Key facts
- Under DSA Article 26, covered online platforms must make each ad identifiable and disclose the person on whose behalf it appears, any different payer and the main targeting parameters.
- The European Commission's DSA questions and answers confirms that public ad repositories are required for very large online platforms and very large online search engines.
- As of 17 October 2026, the Commission's designated-service list identifies Google Search, Bing and ChatGPT as very large online search engines. Article 33(6) sets the additional duties' start date at four months after notification of designation.
Which service classification matters?
DSA Article 3 defines an online platform as a hosting service that stores information at a user's request and disseminates it to the public, subject to an exception for minor, purely ancillary features. Hosting means storing information provided by, and at the request of, a service user.
Article 3(j) separately defines an online search engine through queries searching, in principle, all websites or all websites in a particular language. Results can appear in any format. Applying these definitions to AI search therefore requires examining the service's functions, including its storage and search activities.
Article 26 addresses online platforms. Article 39 expressly covers both designated very large platforms and designated very large search engines. Search-engine status alone does not bring a service within Article 26's platform category.
Article 19 exempts qualifying micro and small platform providers from the section containing Article 26, with a transition period after loss of that status. Designated very large platforms remain covered. Article 33 combines the threshold of at least 45 million average monthly active recipients in the Union with a Commission designation.
What must the individual ad disclose?
Article 26(1) requires clear, concise and unambiguous identification in real time for each ad shown to each individual recipient. It specifies:
- A prominent marking identifying the information as advertising.
- The natural or legal person on whose behalf the ad appears.
- The natural or legal person who pays, when different.
- Meaningful information, directly and easily accessible from the ad, about the main parameters determining its recipient and, where applicable, how to change them.
An ad label addresses only the identification element; the remaining disclosures are separate requirements. Article 26(2) also requires a tool for users to declare promotional content they supply and clear, real-time markings following that declaration.
For paid placements, Article 3(r) defines advertising by reference to promotional information presented on an online platform against remuneration specifically for promoting it. This makes the payment and promotional arrangement relevant when assessing a placement involving a business website.
What does the public repository contain?
Article 39(1) requires a public repository accessible through a reliable search tool supporting multiple search criteria and through application programming interfaces, which allow software access. The retention period covers the ad's display and one year after its last appearance.
Under Article 39(2), its records include ad content, the product, service or brand, the person represented, any different payer, display dates, audience selection and exclusion parameters, and recipient totals. Where applicable, reach figures are broken down by Member State for targeted groups. Declared promotional content on very large platforms is also included.
Article 39(1) excludes recipients' personal data from the repository. Article 39(3) provides special handling for ads removed for alleged illegality or incompatibility with service terms, substituting specified decision information for their content and advertiser identity fields.
Related terms
- DSA advertising transparency
- DSA advertising repositories
- DSA recommender system transparency
- Which DSA platform duties have a microenterprise exemption?
FAQ
Does an AI-generated answer automatically make the service an online platform?
Classification follows the functions defined in Article 3. For an online platform, the test includes hosting and public dissemination at a user's request; the search-engine definition permits results in any format.
What should I check when buying a placement?
Use Article 26's fields to check the ad marking, represented person, any different payer and accessible targeting explanation where that provision applies. For a designated very large service, check Article 33(6)'s notification-based start date and the public repository required by Article 39.
Who owes these DSA disclosure duties?
Articles 26 and 39 place these obligations on the relevant service providers. Article 2(4) preserves other applicable Union rules, including consumer protection and personal-data protection law.
Sources
- European Parliament and Council, "Regulation (EU) 2022/2065 (Digital Services Act)", 19 October 2022
- European Commission, "Digital Services Act: Questions and Answers", updated 19 December 2025
- European Commission, "Supervision of the designated very large online platforms and search engines under DSA", updated 15 October 2026
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