Advertising Agencies in 2026: Liability for Greenwashing Copy of Clients

Who is liable if the agency writes greenwashing copy, the client approves it and publishes it – and a warning notice is issued? The answer is: both. But the defendant is always the client (advertiser). The agency can subsequently seek recourse from the client.

Legal situation: Section 5 of the Unfair Competition Act (UWG) states that anyone who “performs a commercial act which is capable of inducing a consumer to take a commercial decision” is liable. This is primarily the advertiser (client). However, the agency can be jointly liable under Section 8(2) UWG if it is a “co-perpetrator” or “instigator” – in the case of intentionally incorrect advice.

How responsibility is divided between agency and client is, in practice, a matter for the contractual arrangement between the parties. Topics that typically arise in the agency-client relationship include the client’s cooperation in supplying evidence, the design of an approval process before publication, and questions of how liability is allocated. How these points are settled in concrete terms is an individual contractual question and belongs in qualified legal hands.

In practice, agencies often pre-check marketing texts for substantiated statements before they go to the client, and document the corresponding source for every claim (certificate number, LCA study, standard reference). Such procedural precautions do not replace a legal assessment of the individual case.

Sweeping advertising promises such as “We make you EmpCo-compliant”, “guaranteed protection against warning notices”, or “we assume the liability” are discussed in the literature as legally delicate, because they suggest assurances that cannot be kept in that form.

This article is general information and not legal advice. The concrete drafting of contracts and the assessment of the individual case belong in qualified hands.