What is a non-disclosure agreement (NDA)?

What is a confidentiality agreement? It is a contract in which parties agree not to share confidential information received from each other with third parties or to use it for other purposes. The English term is NDA (non-disclosure agreement). You use the agreement before sharing business-sensitive information: during an acquisition, a collaboration, engaging a supplier, or discussions with an investor. Below is what the NDA regulates, when it is unilateral or reciprocal, and what to look out for.

The short answer

• What: Contract to protect confidential information when sharing it.
• Other name: NDA (non-disclosure agreement) or confidentiality agreement.
• Two forms: unilateral (one party shares) or reciprocal (both shares).
• Core: definition of confidential information, permitted use, duration, and consequences of breach.
• When: before you share sensitive data, not afterwards.
• Enforcement: often with a penalty clause, because damage is difficult to prove.

What is the purpose of an NDA?

A confidentiality agreement stipulates that the receiving party keeps information secret and uses it only for the agreed purpose. Without such an agreement, it is not always clear whether data is confidential, and it is difficult to enforce compliance after a leak.

Typical situations: a product idea you discuss with a manufacturer, customer data you share with a software supplier, figures a buyer wants to review during an acquisition, or a recipe you entrust to a packer. In all these cases, you want to ensure that the other party does not pass the information on to a competitor and does not misuse it themselves.

Unilateral or reciprocal

There are two basic forms, and the distinction determines which text you need.

• Unilateral NDA: one party provides the confidential information, the other receives it and keeps it secret. Example: you share your customer database with a marketing agency.
• Reciprocal NDA: both parties share sensitive information and commit to mutual confidentiality. Example: two companies explore a collaboration and show each other their figures and working methods.

A reciprocal agreement often feels more balanced and is common in an equal partnership. In a unilateral situation, a unilateral NDA is actually cleaner: the obligations lie where the risk resides.

What is confidential information?

The heart of every NDA is the definition of confidential information. Too broad, and the agreement becomes unenforceable; too narrow, and too much falls outside its scope. A common definition covers:

• Company data: figures, prices, margins, customer and supplier lists.
• Technical information: designs, source code, recipes, methods.
• Strategy: planning, acquisitions, marketing, product development.
• Anything designated as confidential, whether verbally or in writing.

Clarity upfront prevents disputes afterwards. Some agreements require written documents to be marked as “confidential”; that is strict, but unambiguous.

Exceptions to confidentiality

A good NDA specifies information that is *not* subject to confidentiality. Without these exceptions, the agreement quickly becomes unreasonable. By default, information is excluded that:

• was already public or becomes public through no fault of the recipient;
• already lawfully knew the recipient prior to the provision;
• the recipient received from a third party who did not breach confidentiality;
• pursuant to the law or a court order must be issued.

Duration and duration

Two terms overlap and should be arranged separately. The duration of the agreement itself (for example, for the duration of the negotiations or cooperation) is different from the period during which confidentiality remains in effect. That confidentiality often continues for years after its conclusion — two, five, or indefinite, depending on how sensitive the information is. For trade secrets that do not lose their value, such as a recipe, a long or unlimited term is justifiable.

Penalty clause and enforcement

In the event of a breach, the damage is difficult to prove and quantify in monetary terms. Therefore, an NDA almost always includes a penalty clause: a fixed amount per violation, sometimes increased by an amount per day that the breach continues. This acts as a deterrent and simplifies enforcement, as you do not have to prove the exact damage. Pay attention to the relationship to statutory damages: specify whether you can also claim actual damages in addition to the penalty.

NDA versus confidentiality clause in the employment contract

A standalone NDA is not the same as a confidentiality clause in an employment contract. For employees, confidentiality is usually regulated within the employment contract or the personnel regulations, often linked to a penalty clause and sometimes to a non-competition clause. A separate NDA, on the other hand, is used specifically for parties outside your organization: suppliers, consultants, prospective buyers, and freelancers. For a self-employed professional who is not an employee, a separate confidentiality agreement is indeed the appropriate route.

Honest recommendation

For a simple, standard situation—you share limited information with one trusted party—a good model agreement often suffices perfectly. You do not necessarily need a lawyer for this; a sound model with a clear definition and a realistic penalty clause goes a long way. However, do engage legal assistance if there is a lot at stake: an acquisition, unique intellectual property, foreign parties, or a counterparty presenting an extensive NDA of their own. Always have a presented NDA reviewed before signing—the risks often lie in the definition, the duration, and the penalty clause.

Want to know more? View the confidentiality agreement, read how to draft a confidentiality agreement , and which pitfalls and penalty clauses you need to be aware of.

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