The repository is the technical half of a law that already binds advertisers. The Regulation on Political Advertising, EU 2024/900, has applied in full since 10 October 2025. What was missing until this month was a single place to look. The platform's structure follows Implementing Regulation (EU) 2026/818, adopted earlier this year, according to the Digital Watch Observatory.
For an ordinary reader, the effect is unglamorous and useful at the same time. If a party, a candidate or a campaign group paid to show you a message, the paperwork behind that message should end up in one searchable database instead of disappearing when the campaign ends.
A pilot repository, open since 12 October
The Commission describes the current stage as a pilot open to voluntary use by publishers. There is no announced date for when handing over the data becomes compulsory. That date matters more than the launch, because the obligations attached to it are strict.
The repository sits alongside a network of national contact points. These are the authorities in each member state that deal with political advertising in their own country. The network exists so that a complaint about a cross-border campaign does not die at a border, which is a real problem in a union where a Czech voter can be targeted by a Slovak or German campaign, and the other way round.
What each transparency notice holds
Each entry in the repository is a transparency notice. Compiled from the regulation, it carries:
- the sponsor of the advertisement;
- the entity that paid for it or controls it;
- the sources of the funding;
- the amounts spent;
- the period during which the advertisement was displayed;
- the targeting criteria used to decide who saw it;
- whether AI systems were involved in preparing or placing it.
Targeting criteria is the part citizens tend to care about most. A notice describes the categories used to select an audience. It is not a list of the individuals reached.
Seven years of searchable history
Advertisements and their notices must stay in the repository for seven years after the date an advertisement was last displayed. That number is doing real work. A claim about who paid for a message can be checked long after the votes are counted, during a court case or a later campaign.
Compare it with the memory of a social feed, which is measured in weeks. Election researchers in several EU countries have spent years rebuilding deleted ad data by hand. A retention rule of seven years removes part of that labour, at least for advertisements that fall inside the regulation's scope.
Voluntary now, binding later
Once the mandatory rules apply, general online publishers will have to transmit transparency information to the repository within 72 hours of an advertisement's first publication. That window is short. A news site with a handful of staff will need a workflow that pushes the data automatically rather than a spreadsheet someone fills in on Friday afternoon.
Non-compliance can cost up to 6% of annual global turnover in severe or repeated cases. That is a ceiling, not a typical fine, and it sits above the 4% or €20 million that GDPR allows. For smaller outlets the practical pressure is less about the maximum and more about the engineering work a 72-hour deadline creates.
The AI field in the notice
One field asks whether AI systems were used. That connects to Article 50 of the EU AI Act, the transparency duties that took effect on 2 August 2026. Those rules require synthetic content to be marked and users to be told when they are interacting with an AI system rather than a person.
So a single advertisement can now trigger two separate sets of paperwork: one about who paid for it, one about how it was made. A video that puts a candidate's face into a scene they never stood in would fall foul of the labelling duty before anyone argues about the funding.
High-risk AI rules are a different track. Under the Digital Omnibus on AI, Regulation (EU) 2026/1744, the compliance deadline for standalone Annex III systems in areas such as recruitment, credit scoring and education moved from 2 August 2026 to 2 December 2027. That change concerns systems that make consequential decisions about people. The ad repository has its own schedule.
Dates to keep track of
| Date | What it means |
|---|---|
| 10 October 2025 | Regulation (EU) 2024/900 on political advertising applies in full |
| 2 August 2026 | AI Act Article 50 transparency duties for synthetic media and chatbots take effect |
| 12 October 2026 | Pilot version of the European Repository opens for voluntary use |
| 4 November 2026 | Commission holds an Implementation Dialogue in Brussels, hosted by Commissioner Michael McGrath |
| To be announced | Date from which publishers must transmit transparency notices |
| 2 December 2027 | Deadline for standalone high-risk AI systems under Annex III, moved by the Digital Omnibus |
Open questions before November
The 4 November meeting in Brussels is where the Commission intends to hear how the first publishers coped. Three things are still unclear. The mandatory deployment date has not been set. It is not yet settled how much technical support small and medium publishers will receive for the 72-hour transmission rule. And the repository's usability for a non-specialist, someone who wants to check an advertisement they saw on a local news site, has not been tested publicly at any scale.
Until then, the platform exists, it is open, and the entries inside it depend on who chooses to fill them in.
Can I look up an advertisement I saw on a social platform?
The repository covers political advertising services offered in the EU, and it is publicly accessible. Very large online platforms also have their own advertising transparency duties under European rules, so the answer depends on where the advertisement appeared and whether the advertiser falls inside the regulation's scope.
Does the repository contain my personal data?
The notices list sponsors, paying entities, funding sources, amounts, display periods and targeting criteria. They describe the audience categories used, not the names of the people who saw the advertisement. Personal data questions still fall under GDPR.
Do small publishers have to use it now?
No. The current phase is voluntary, and the Commission has not announced when transmission becomes mandatory. The 72-hour deadline and the turnover-based penalties apply only once that mandatory date takes effect.
