Betriebsrat First: Getting the Works Agreement Right Before You Run AI Review on Employee Mailboxes

When a German company needs to review its own employees' mailboxes, for an internal investigation, a regulator's request or a dispute, one of the first conversations is with the works council. The Betriebsrat has no say over whether the company investigates. It does have a say over the technical systems the company uses to do it, and an AI review platform reading employee email is one of those systems.

That distinction shapes the whole project. A team that settles the tooling with the works council in advance can start a review when the need arises, while a team that negotiates mid-investigation may find the review waiting on the talks. This story looks at where co-determination applies, what a works agreement (Betriebsvereinbarung) for an AI review platform usually covers, and how Claira inside Nuix Discover can be described in one.

The tooling is co-determined, the investigation stays with the employer

Section 87(1) no. 6 of the Works Constitution Act gives the works council a right of co-determination over the introduction and use of technical devices designed to monitor the conduct or performance of employees. Where the parties cannot agree, the conciliation committee (Einigungsstelle) decides under section 87(2).

The statute says nothing about investigations as such. As Mayer Brown's employment team reads the law in its October 5, 2026 briefing on internal investigations, the investigation itself is not subject to co-determination, while the systems used to carry it out can be, email systems among them. The council keeps its information rights under section 80 throughout, and the briefing suggests that in a single case the employer shares only what the council needs for its statutory tasks.

The Federal Labour Court showed how this works in its decision of March 23, 2021 (1 ABR 31/19). An airport operator had reviewed and secured employees' emails in an internal investigation and passed them to outside lawyers and auditors. The court left open whether a fresh co-determination right arose, because a works agreement from 2010 already governed control measures to detect criminal offences, with conditions on documented suspicion, necessity and proportionality. The council had exercised its right in advance, so no separate consent was needed for each measure. The court also held that a works council's claim to remedy a breach of section 87 ends the unlawful state itself and does not reach its consequences, such as data already passed to third parties.

Why an AI review platform counts as tooling

In its decision of January 16, 2024 (24 BVGa 1/24), the Hamburg Labour Court found that letting staff use ChatGPT through their own private accounts did not trigger section 87(1) no. 6, because the employer had no access to the data the system collected. As Gleiss Lutz notes in its commentary, the position may differ where the employer runs the AI system itself or gains access to its data.

A review platform that the employer runs over its employees' mailboxes sits on the other side of that line. It reads what custodians wrote, and it also records what reviewers do: if the reviewers are the company's own legal or compliance staff, their work in the tool is employee data too. Section 90 adds a duty to inform and consult the council in good time when planning technical systems and work processes, expressly including the use of artificial intelligence, and section 80(3) treats an expert as necessary whenever the council has to assess the introduction or use of AI.

What the works agreement needs to say

A framework agreement on the 2010 model lets the company act when a matter arises, because the conditions are set in advance. Mayer Brown's briefing lists purpose, scope, access concepts, retention periods, review mechanisms and data protection safeguards as the core of such a framework. For an AI review platform, those headings become a handful of practical questions.

The agreement can define the triggers for a review (a documented suspicion, a regulatory request or a court order) and the person who decides. It can set how the review set is scoped, by custodians, date ranges and data sources, and how private communications are handled. It can name the roles that may write prompts, run reviews and see results, and require a lawyer to approve the instructions before a review runs at scale. It can state that the system supports human reviewers and that people take any decision about an employee. It can also cover documentation, retention and deletion, the information the council receives at system level and in each case, and the use of the platform's records about the reviewers.

The agreement does not replace the data protection analysis. In its judgment of December 19, 2024 in case C-65/23, the Court of Justice of the European Union held that a works agreement made under Article 88 GDPR must also meet the GDPR's general requirements, including Articles 5, 6(1) and 9, and that national courts can review the necessity of the processing in full. As CMS's employment team reads the judgment, the parties have no margin to agree a lower standard. A dedicated German employee data act would change the frame, but as of June 2026 a new federal draft was still being prepared and nothing had been adopted.

Describing Claira in the agreement

A works council will want an accurate description of the system in the annex, and the help centre supplies the facts. Claira works on each document's extracted text and writes its results to fields in Nuix Discover. According to the help centre's privacy and security article, Claira does not store the content of your documents or the answers its scans produce: the Nuix Discover field holds the only copy. Claira can keep a case's data in the EU, and model requests are processed inside the deployment's country.

The same article lists what Claira does keep, including the Case Contexts and Insights a team creates and Agent Mode chats, which the changelog says are deleted permanently after seven days since the release of October 7, 2026. Claira also keeps internal working notes on how people use it, such as the kinds of tasks each person does and their role in a case, never document content or prompt text. An organisation can ask for these notes to be switched off, which deletes them, a point worth settling in the agreement.

The review itself can follow the steps an agreement asks for. A team can brief the matter in Case Context using the Internal Investigation template, bearing in mind that a context is visible to everyone on the case. Prompts are tested through single review, which recommends 10 to 25 representative documents, before a bulk scan runs across the agreed set. The Bulk Task History Report exports each task's details, prompt text, model and comments as a PDF, a record the council and auditors can read, and a Prompt Log field can record the prompt beside each result.

We followed a German internal investigation of this kind, from whistleblower report to review, in our Casebook entry on a cartel report in four languages.

Betriebsrat first

The practical lesson from the case law is timing. An agreement negotiated before any investigation can be specific about the system and its safeguards without discussing any individual employee. Negotiated under pressure, the same document invites delay, and Mayer Brown notes that a breach of co-determination over monitoring systems can give the council a claim to stop the measure.

If you are preparing that agreement and want to see how Claira would sit inside it, our team can walk you through it on your own documents.