Confidentiality agreement (NDA) in a property sale

A confidentiality agreement (Vertraulichkeitsvereinbarung, in English non-disclosure agreement, NDA for short) obliges prospective buyers to use information about a property only to assess the purchase and not to pass it on to third parties. It is concluded before the exposé and documents are handed over. An NDA deters and creates a basis for claims – but it cannot prevent disclosure. That is why it works best in combination with vetted buyers, staged releases and a log.

What is a confidentiality agreement in a property sale?

A confidentiality agreement is a contract in which the recipient of information undertakes to keep it confidential. In Germany, there is no specific statutory regulation for NDAs. They are based on the freedom of contract under the German Civil Code (BGB).

In a property sale, an NDA mainly occurs in three situations:

• Off-market sale: The property is not offered publicly; only selected buyers receive details.
• Investment and commercial properties: Tenant lists, tenancy agreements and income figures are commercially sensitive.
• Homes of prominent people or high-end homes: Location, floor plans and fittings should not become public.

More background in the guide What is off-market property?.

Who concludes the agreement with whom?

As a rule, the prospective buyer concludes the NDA with the owner, the estate agent or both. At diskret.immo, the vetted buyer gives a digital confidentiality undertaking when requesting the exposé. Companies sign through their authorised representatives; the buyer’s advisers are often expressly included.

What does a confidentiality agreement cover?

A good NDA is short, understandable and precise. These points typically belong in it:

At diskret.immo, a uniform agreement applies to all exposés.

When is the confidentiality agreement concluded?

The NDA is concluded before confidential information flows – that is, after the anonymous profile and before the exposé. Anyone who only demands an agreement after handing over documents no longer protects anything the buyer already knows.

At diskret.immo, the order is fixed: stage A (anonymous profile) is visible without an NDA because it contains no identifying information. For stage B (exposé), the account must be vetted and the buyer gives a confidentiality undertaking; the release is only granted with the owner’s consent. For stage C (address), the same agreement continues to apply; the address is only given after a further release.

What applies to tenant data and other personal data?

With let properties, the documents often contain personal data: tenants‘ names, start of tenancy, rent level, arrears. In addition to the NDA, the General Data Protection Regulation (GDPR, in German DSGVO) applies to this data. The owner may only pass it on to the extent necessary for the sale.

In practice this means: an anonymised tenant list without names is sufficient for the first review. Only a buyer who is seriously about to purchase receives the full tenancy agreements – at diskret.immo only at stage C, handed over personally by our team. The NDA should expressly provide that such data is deleted if talks are broken off.

Is a contractual penalty advisable?

A contractual penalty (§ 339 BGB) obliges the recipient to pay a predetermined amount in the event of a breach. The advantage: the owner does not have to prove a specific loss, which is otherwise often difficult with breaches of confidentiality.

However, a contractual penalty must be reasonable. If the agreement is a pre-formulated text for many cases – such as an online form – it is subject to review as standard business terms (Allgemeine Geschäftsbedingungen, §§ 305 et seq. BGB). An unreasonably high penalty can then be invalid under § 307 BGB. Particular restraint is required towards consumers. Unlike with an individually negotiated agreement, a court does not reduce an excessive penalty in pre-formulated terms – it lapses entirely. In practice, it is therefore often agreed that the entitled party sets the penalty in the individual case at its reasonable discretion and that a court can review it. If the penalty in an individually negotiated agreement is disproportionately high, a court can also reduce it on application (§ 343 BGB); this does not apply to merchants acting in the course of their commercial business (§ 348 German Commercial Code, HGB).

Where are the limits of an NDA?

A confidentiality agreement is a useful tool, but not a shield. The most important limits:

1. It does not prevent disclosure. It only creates claims afterwards. What has been passed on once cannot be retrieved.
2. Proof is difficult. Without a log and without knowing who received which document, it is often impossible to prove who passed on a piece of information.
3. The loss is hard to quantify. Without a contractual penalty, the owner must prove a specific loss.
4. It only binds the contracting parties. Third parties who receive information are not bound.
5. What is public stays public. What is already known, for example through an earlier listing, can no longer be protected by an NDA.
6. Statutory obligations take precedence. Duties to provide information to authorities or courts remain.
7. Unclear clauses do harm. Provisions that are too broad or unclear may be invalid.

No legal advice. The notes on §§ 305 et seq., 307, 339, 343 BGB and § 348 HGB reflect the general position under German law as of 26.10.2026. For drafting or reviewing a confidentiality agreement, please consult a lawyer.

What protects alongside the NDA?

Because an NDA alone is not enough, a well-thought-out discreet sale relies on several levels. At diskret.immo, these are:

Effective protection only arises from the interplay: the stages limit what gets into circulation in the first place. The log and personal handover show who received what. The NDA creates the legal basis for deriving claims from this. More on the page Security and discretion.

Who is bound to confidentiality anyway?

In Germany, some parties are already bound to confidentiality by virtue of their profession, without the need for an NDA:

• Notaries under § 18 Federal Notarial Code (Bundesnotarordnung)
• Lawyers under § 43a(2) Federal Lawyers‘ Act (Bundesrechtsanwaltsordnung)
• Tax advisers under § 57(1) Tax Advisory Act (Steuerberatungsgesetz)

For estate agents, there is no comparable general statutory duty of confidentiality. Their duty of confidentiality follows from the agency contract; the GDPR also applies to personal data. Anyone wishing to sell discreetly should therefore agree on it expressly.

Do I have to sign an NDA as a buyer?

No one is obliged to sign a confidentiality agreement. Without one, however, you will usually not receive any details in a discreet sale. As a buyer, you should check four points before signing:

• May you involve your bank, your lawyer and your tax adviser?
• How long does the agreement apply?
• Is a contractual penalty agreed, and how high is it?
• Does the NDA oblige you to pay a commission or to buy? It should not – an obligation to pay commission belongs in a separate agency contract.

In Germany, for apartments and single-family houses, an agency contract must be in text form (§ 656a BGB). An NDA does not replace it.