Evidence preservation

Evidence preservation means keeping records, documents, and data safe and unchanged so they can be used later to prove what happened. In political advertising, it includes saving ad content, targeting details, payment records, and transparency information in case of investigations, audits, or legal disputes.

Legal Basis

While Regulation 2024/900 does not use the term "evidence preservation" explicitly, it requires providers and sponsors to maintain records and make information available to competent authorities:

"Providers of political advertising services shall keep at the disposal of the competent authorities the information referred to in paragraph 1 for a period of three years after the date of last publication of the political advertising."

— Article 8(3), Regulation (EU) 2024/900

Additionally, publishers must establish and maintain easily accessible reporting channels for possible breaches, and competent authorities have powers to request information and conduct investigations.

Why It Matters

Evidence preservation protects everyone involved in political advertising. For regulators and enforcement authorities, preserved evidence makes it possible to investigate complaints about missing labels, fake sponsors, or illegal targeting techniques. Without reliable records, it's almost impossible to prove that a rule was broken or to hold the right party accountable.

For publishers, platforms, and sponsors, keeping clear evidence protects against false accusations and helps demonstrate compliance. If a complaint is filed months after an ad campaign ends, detailed records show exactly what was published, who paid for it, and how it was targeted. This documentation is essential during audits, in court proceedings, or when responding to requests from data protection authorities or media regulators.

The three-year retention period under the TTPA regulation aligns with enforcement timelines and statutes of limitation in many Member States. During this time, evidence must remain accessible, authentic, and complete—meaning it cannot be altered, deleted, or lost due to poor storage practices.

Key Points

Three-year retention: Providers must keep transparency information available to competent authorities for three years after the last publication of a political ad
Scope of evidence: Includes ad content, sponsor details, amounts paid, targeting parameters, delivery data, and transparency notices
Accessibility: Records must be kept "at the disposal" of competent authorities, meaning they can be retrieved and shared on request
Integrity: Evidence must be stored in a way that prevents tampering, loss, or unauthorized alteration
Cross-regulation: GDPR limits how long personal data can be stored—evidence preservation must balance TTPA retention rules with data protection principles
Audit trail: Good practice includes logging who accessed, modified, or shared evidence, especially for sensitive targeting data

Evidence preservation vs. Transparency obligations

Evidence preservation and transparency obligations are closely connected but serve different purposes. Transparency obligations require sponsors and publishers to label political ads and make information publicly visible in real time—such as who paid for an ad or how many people saw it. These obligations help voters recognize and understand political advertising as it happens.

Evidence preservation, by contrast, is about keeping records of that transparency information (and other details) after the ad campaign ends. It's a safeguard for enforcement: even if a transparency notice was displayed correctly, authorities may need to verify it months or years later. Evidence preservation also covers internal records that are not always public, such as contracts, payment receipts, and targeting instructions. In short, transparency is about showing information now; evidence preservation is about being able to prove it later.

Related Terms

Political advertising service
Sponsor
Publisher
Provider of political advertising services
Targeting techniques
Transparency notice
Competent authority
Data protection authority
Record-keeping
Ad repository

Very transparent. Every political ad will be labelled, linked to a transparency notice with detailed information, and online ads will be searchable in a central European repository.

The Network coordinates election-related cooperation between member states. National contact points for TTPA enforcement should be members of this network where possible.

Election campaigns will need to ensure all paid advertising includes proper labels and transparency notices. Sponsors must be prepared to provide required information to all service providers.

Several major platforms currently do not allow paid political advertising, including some large social networks. This limits where political actors can place paid online advertisements.

The TTPA applies from 10 October 2025. Member States had until 10 April 2025 to designate competent authorities, and the Commission must provide label templates by 10 July 2025.

Publishers must ensure completeness and accuracy of certain information but are not required to verify all sponsor claims. They must correct manifestly erroneous information when they become aware of it.

Yes. When a hosting provider and a website both display an ad, both are considered publishers with responsibility for their specific services. Contracts should clarify how they share compliance duties.

If a publisher removes or disables access to a political ad due to illegality or terms violations, they must still provide access to the transparency information for the full seven-year retention period.