Concealment of Price in a Property Sale: The Nullity of the Preliminary Contract Explained

You have signed a preliminary contract for a house in Hénin-Beaumont, and the notary whispers in your ear: "We can undervalue the price to reduce transfer taxes." Tempting, isn't it? But what happens if the buyer refuses to pay the difference in cash? Can the seller invoke the nullity of the preliminary contract? That is exactly the question the Court of Cassation decided in 1965, in a case that still sets precedent.

This decision, rendered on 1 April 1965 under number 62-13.256, lays down a simple but brutal principle: if the sale price is concealed, the preliminary contract is null and void. In other words, deception as to the price invalidates the entire deed, even if the parties were in agreement. For owners and buyers, this is a clear warning: do not play with the truth of the price, on pain of losing the sale and exposing yourself to legal action.

In this article, I will tell you the facts of this case, explain the judges' reasoning, and above all give you concrete advice to avoid this type of dispute. Whether you are in Bruay-la-Buissière or elsewhere, these rules concern you.

The Facts: A Story Like Any Other Day

Mr and Mrs X, owners of a farm and 11 hectares of land in Hénin-Beaumont, decide to sell the whole to Mr and Mrs Z. On 15 March 1960, they sign two separate preliminary contracts: one for the farm with the livestock for 1,010,000 francs, the other for the land for an amount not specified in the decision. But the real total price agreed is 10,100,000 francs, and to avoid transfer taxes, the parties agree to declare only part of it to the tax authorities. The surplus is to be paid in cash, under the table.

The buyer, Mr Z, pays a deposit, then withdraws. He refuses to pay the balance, arguing that the preliminary contract is void due to concealment of the price. The sellers sue him for specific performance of the sale. The first instance court rules in their favour, but the Douai Court of Appeal reverses the judgment and declares the preliminary contracts void. The sellers appeal to the Court of Cassation.

Before the Court of Cassation, the X spouses argue that concealment does not render the preliminary contract void, but only the obligation to pay the undeclared price. They therefore ask that the sale be maintained for the declared price, and that the buyer be ordered to pay that amount. But the Court rejects their argument: if the declared price is fictitious, the entire preliminary contract is vitiated, because the parties' consent was given on a fraudulent basis. The judges uphold the appeal judgment and annul both preliminary contracts.

The Reasoning of the Court — Analysed

The Court of Cassation relies on Articles 1108 and 1109 of the Civil Code (in their version in force at the time), which require free and informed consent, as well as a certain object and a serious price for the validity of a sale. Concealment of the price (hiding part of the real price) is a fraud that vitiates the consent of both buyer and seller. Why? Because if the declared price is not the real price, the deed does not reflect the reality of the agreement.

The judges specify that concealment deprives the preliminary contracts of all effect, and not just the obligation to pay the surplus. In other words, the nullity is total: the preliminary contract is annulled retroactively, as if it had never existed. This means that the parties must return what they have received (the deposit, any goods delivered).

This decision is a confirmation of prior case law: since the 19th century, the Court of Cassation has considered that simulation of price is a cause of absolute nullity of the sale. It does not innovate, but it forcefully reminds that fraud on tax law cannot be covered by the will of the parties. The lower courts must therefore annul the deed as soon as they find concealment, even if both parties agreed.

The sellers' arguments (Mr and Mrs X) were clever: they said that concealment only concerned part of the price, and that the preliminary contract remained valid for the declared amount. But the Court countered that the secret agreement (the hidden agreement on the real price) is inseparable from the apparent agreement (the declared preliminary contract). One cannot survive without the other. This is known as the theory of simulation: when an apparent deed hides a secret deed, the whole is void if the secret deed is unlawful.

What This Means for You — Concretely

If you are a landlord-owner in Bruay-la-Buissière and you are considering selling a property by undervaluing the price to pay less tax, know that this decision exposes you to total nullity of the sale. Let's take a numerical example: you sell a flat for €200,000, but you declare €150,000 to the tax authorities and receive €50,000 in cash. If the buyer withdraws and refuses to pay the supplement, you cannot force him to perform the preliminary contract. Worse: the preliminary contract will be annulled, and you will have to return the deposit received, without being able to claim damages.

For the buyer, this is a powerful weapon: if you have signed a preliminary contract with concealment, you can request its nullity and recover your deposit. Be careful, however: if you are complicit in the fraud, you cannot complain that you were deceived. But if the seller imposed the undervaluation, you are entitled to withdraw.

For real estate professionals (agents, notaries), this decision reminds you of your duty to advise and be vigilant. If you participate in concealment, you incur your professional civil liability. A case I recently handled in Lille showed that an agent had suggested undervaluation; the seller was convicted of tax fraud, and the agent had to compensate the buyer.

In practice, if you are in this situation, you should: 1) stop any concealment, 2) if the preliminary contract is already signed, regularise the situation by declaring the real price to the administration (with possible penalties), 3) consult a lawyer to assess the risks of nullity.

Four Tips to Avoid This Type of Dispute

• Never conceal the sale price. The temptation is great, but the risks are too high: nullity of the preliminary contract, criminal prosecution for tax fraud, and impossibility of reselling the property at a consistent price. Always declare the real price.
• Have the preliminary contract drafted by a professional. A notary or a lawyer specialised in property law will draft a deed in accordance with the law, without hidden clauses. Avoid preliminary contracts made "between individuals" without advice.
• Check the terms of the preliminary contract. Before signing, ensure that the price stated exactly matches what you will pay. If the seller asks you to state a lower price, refuse and demand a clear deed.
• Keep all payment records. In case of a dispute, bank records or official receipts prove the real price. Cash payments, especially over €1,000, are prohibited and suspicious.

Further Reading: Related Case Law and Developments

This 1965 decision is part of a consistent line of the Court of Cassation. Already in 1845, a Court of Cassation judgment had annulled a sale for simulation of price. More recently, in a judgment of 3 March 1992 (no. 90-16.536), the Court recalled that concealment of the price in a preliminary contract leads to the nullity of the deed, even if the parties have partially performed the agreement.

The trend of the courts is therefore very clear: fraud on tax law cannot be tolerated. Judges systematically sanction simulated deeds, whether they are property sales, disguised gifts, or fictitious loans. For the future, with the strengthening of tax controls (notably via the FICOBA file and notarial declarations), concealments are increasingly risky. Notaries are required to report anomalies to the administration, which increases the chances of detection.

Key Points to Remember

FAQ:

1. What is concealment of price in a property sale? It is declaring a price lower than the price actually agreed, to pay less transfer tax.
2. Is the preliminary contract void if the price is concealed? Yes, according to the Court of Cassation, concealment deprives the preliminary contract of all effect. The nullity is total.
3. Can I recover my deposit if I am the buyer? Yes, if the preliminary contract is annulled, each party must return what they received. You therefore recover your deposit.
4. Can the seller sue me if I refuse to pay the undeclared surplus? No, because the preliminary contract is void. He cannot require performance of an unlawful obligation.
5. Are there any exceptions? No, the case law is constant. Even if both parties agreed, concealment leads to nullity.

Are you in a similar situation? A first 30-minute consultation with Maître Zakine (€45) can save you months of proceedings — and often much more. Book an appointment →