Confidentiality in mediation: How does it work?

For many entrepreneurs, confidentiality is one of the greatest benefits of the mediation process. Everything you discuss remains strictly between you and the other party. But is that entirely accurate? As a mediator, I notice this topic often raises questions, especially when a conflict threatens to escalate into a lawsuit. In this article, I explain how confidentiality in mediation is legally regulated, where the boundaries lie, and how I protect your interests as a mediator.

Why confidentiality in mediation is crucial for entrepreneurs

Entrepreneurs involved in a conflict with a business partner, shareholder, or supplier want to speak openly without every statement being used against them later. That is exactly the power of mediation: the space to be honest, explore compromises, and discuss solutions that would never be considered in a courtroom.

But what if the mediation fails and one party decides to go to court? Can the judge summon me as a mediator to testify about what was said during the sessions? The answer is more nuanced than most people think.

Does a mediator have legal professional privilege?

In the Netherlands, we have the concept of functional professional privilege: the right of certain professionals to refuse to appear as a witness because they are bound by secrecy due to their profession. Think of lawyers, notaries, and doctors. They do not have to answer questions about confidential information.

However, a mediator does not have this legal right. The Supreme Court explicitly ruled on this in 2009: a mediator cannot invoke functional professional privilege under Article 165, paragraph 2, sub b of the Dutch Code of Civil Procedure. This applies even if the mediator also practices a profession that does have such privilege, such as a lawyer-mediator. Once someone acts as a mediator, the mediation rules apply, not the professional rules of their secondary function.

In short: as a mediator, I am generally obliged to appear as a witness if summoned by the court. However, and this is crucial, that does not mean confidentiality is without protection.

The evidentiary agreement: your strongest protection

In my practice, I work with a standard mediation agreement that includes an explicit evidentiary agreement. This is a written contract between all involved parties, stipulating that any testimony provided by the mediator may not be used as evidence in any potential lawsuit between the parties.

This is permitted under Article 153 of the Dutch Code of Civil Procedure. The law allows parties to deviate from standard rules of evidence, provided it concerns facts over which the parties have free disposal. In almost all business conflicts resolved through mediation, this is the case.

If one party tries to call me as a witness later and the other party invokes the evidentiary agreement, the court will respect that agreement as long as the wording is sufficiently clear. The agreement must explicitly state that testimony from the mediator is excluded as evidence. Vague or general confidentiality clauses are not enough.

What can a judge still do during witness questioning?

Suppose there is no valid evidentiary agreement, or the judge decides to hear me as a witness anyway. The judge still has one tool: they can block certain questions during the witness hearing under Article 179, paragraph 2 of the Code of Civil Procedure. They do this by carefully balancing two interests:

• The public interest in truth-finding in the specific proceedings.
• The interest of confidentiality within the mediation process.

The judge cannot do this lightly and must justify the decision. In practice, this means that sensitive information shared exclusively in the context of mediation has a real chance of remaining outside the courtroom, even without formal professional privilege.

What does this mean for your mediation process?

As an entrepreneur considering mediation for a business conflict, here are the practical consequences:

• Always sign a comprehensive mediation agreement: no oral agreements on confidentiality, but a written contract with a clear evidentiary agreement.
• Check the text before signing: does it explicitly state that statements by the mediator cannot serve as evidence? If not, ask for an amendment.
• Choose an MfN-registered mediator: I am bound by the code of conduct of the MfN, which includes strict confidentiality obligations toward all parties involved and third parties.
• Be aware of the limits: confidentiality is not absolute. In cases of serious criminal offenses or situations where the legal order is at stake, a judge may rule differently.

Confidentiality in practice: my approach as a mediator

I place great value on a careful start to the mediation process. Before the first session, I discuss with all parties exactly what confidentiality entails, where the boundaries lie, and how the evidentiary agreement is formulated.

Not because I expect things to go wrong, but because that clarity upfront provides peace of mind at the table. Entrepreneurs who know their words are safe dare to speak more openly. And openness is exactly what is needed to reach a solution that truly works for both parties, and for the continuity of the company.

That is the difference with a lawsuit: there, your words become weapons. In mediation, they become tools.

Frequently Asked Questions

Can a mediator be forced to testify in court?

In principle, yes. A mediator in the Netherlands does not have statutory professional privilege and can be summoned by a judge. However, in most cases, a well-drafted evidentiary agreement within the mediation agreement offers sufficient protection, as parties agree that the mediator’s statements cannot be used as evidence.

What is an evidentiary agreement in mediation?

An evidentiary agreement is a written contract, included in the mediation agreement, where the parties agree that the mediator cannot act as a witness in potential litigation. This is permitted under Article 153 of the Code of Civil Procedure, provided it is drafted explicitly and clearly.

Does mediation confidentiality apply to my lawyer?

The confidentiality clauses in the mediation agreement apply to all participants: the parties themselves, the mediator, and any advisors present at the sessions. Your lawyer or financial advisor participating in the mediation is therefore also covered by the evidentiary agreement.

What if the other party uses information from the mediation in court?

If the other party attempts to introduce information from mediation sessions as evidence, you can invoke the evidentiary agreement, and the court will disregard that information. Furthermore, using confidential mediation information may impact the credibility of that party in the proceedings.

Summary: confidentiality in mediation is strong, but not automatic

Confidentiality is one of the most important benefits of mediation, but it is not automatic. A mediator in the Netherlands does not have legal professional privilege. What truly secures your confidentiality is a well-drafted evidentiary agreement within your mediation contract. As an MfN-registered mediator, I ensure this agreement is clear and complete at the start of every case, allowing you to speak freely and work toward a solution that keeps your business and relationships intact.