Supplementary terms for AI services
Last updated: November 2026. This English version is a convenience translation. Only the German version is legally binding.
Scope
1.1 These terms apply to AI strategy and consulting, AI design and development, AI support and further development, AI agents as well as workshops, training and talks provided by Essential Advertising GmbH under the lindenbrook brand.
1.2 They apply only to entrepreneurs, legal entities under public law and special funds under public law.
1.3 They supplement the general terms and conditions of Essential Advertising GmbH. In case of conflict, these terms prevail for AI services. The offer prevails over both.
What AI can do and what we owe
2.1 AI systems work with probabilities. Their results may be incomplete, outdated or wrong. We owe professional advice, design, set-up and testing in line with the state of the art, but not error-free results in every single case, unless the offer provides otherwise.
2.2 The client reviews results before using them, especially before decisions with legal, tax, medical or financial effect. Applications we develop provide for human approval where results are sent out or prepare decisions.
2.3 We do not provide legal, tax or medical advice. Notes on data protection, the AI Act and other regulations are general guidance. The assessment of the individual case remains with the client's data protection officer or legal advisers.
2.4 We accept work results against the criteria agreed in the offer, usually by means of test cases. Deviations within what is to be expected of AI systems are not a defect.
Services of other providers
3.1 We use models and services of other providers, such as language models, hosting, databases and speech services. Which ones is stated in the offer or the project documentation. Their terms and usage policies apply in addition, and the client complies with them when using them.
3.2 Providers change models, prices and features. As part of our support we adapt the application. We agree significant additional costs in advance. We are not liable for outages and changes of these providers unless we are responsible for them.
3.3 Usage costs of the providers, for example for language models and hosting, are borne by the client according to consumption. They run via the client's own accounts or via us at the rates in the offer. Included allowances are stated in the offer.
3.4 Where possible, we set up accounts with providers in the client's name. The client transmits access credentials only via the project room.
Data and confidentiality
4.1 Where we process personal data on behalf of the client, the data processing agreement of Essential Advertising GmbH applies, with the sub-processors listed there. Neither we nor the providers we use use the client's data to train AI models.
4.2 The client only provides data that it may use for the agreed purpose. In tests we work with anonymised or made-up data where possible. We process special categories of data under Art. 9 GDPR only by express agreement.
4.3 If the client is subject to professional secrecy under Section 203 of the German Criminal Code, for example in tax advice, law or medicine, we and everyone involved undertake to maintain secrecy under Section 203 (4) of the Criminal Code. On request we conclude the agreement provided for by professional law, for example under Section 62a StBerG or Section 43e BRAO, separately.
4.4 Otherwise, confidentiality under clause 13 of the general terms applies.
AI Act
5.1 If the client uses an application we develop for it under its own responsibility, it is usually the deployer within the meaning of the AI Act, and also the provider if it places it on the market under its own name. We record the roles in the offer.
5.2 Applications with which people talk or write directly state that they use AI. We label AI-generated images, audio and text where the law requires it (Art. 50 AI Act). The client does not remove these notices.
5.3 The client ensures the AI literacy of its staff under Art. 4 AI Act. We offer training for this.
5.4 We develop high-risk applications under Annex III of the AI Act only by separate agreement.
Rights to results
6.1 In addition to clause 9 of the general terms, we grant rights of use to the extent that intellectual property rights exist in the results. Content generated with AI is in part not protected by copyright. We do not warrant such protection.
6.2 Building blocks, tools, templates, prompts and know-how that we also use in other projects remain ours. The client receives a non-exclusive right to use them for the agreed purpose. What we develop exclusively for the client forms part of the results.
6.3 Material the client provides for an application to work with may be used by the client for that purpose. The client indemnifies us against third-party claims based on a lack of these rights.
Workshops, training and talks
7.1 The client may use materials internally and pass them on to its staff. Publication or disclosure outside its organisation requires our consent.
7.2 Recordings are made only with the prior consent of everyone involved.
7.3 Clause 6 of the general terms applies to cancellations and rescheduling. The client may name substitute participants at any time.
7.4 A certificate of attendance confirms attendance, not a particular level of knowledge.
Liability
8.1 Clause 12 of the general terms applies.
8.2 If the client uses results without the intended review or bypasses approvals an application provides for, this is to be taken into account as contributory fault in assessing liability (Section 254 BGB).
References
9.1 Notwithstanding clause 9.8 of the general terms, we name the client as a reference, with name or logo, only after its consent in text form. We publish case studies and quotes only in the version approved by the client.
Version
10.1 Version 1.0, last updated November 2026. The version valid at the time the contract is concluded applies.