Compromis de Vente in Luxembourg: The Preliminary Sales Agreement Explained

In Luxembourg, the most important signature in a property purchase often comes before you meet the notary. The compromis de vente — the preliminary sales agreement — is a short document, but it is a real contract. Once buyer and seller have signed it, the sale is agreed, and walking away has a price.

This guide explains what the compromis is under Luxembourg law, which clauses protect you and what it costs — using only official sources (guichet.lu, the AED, the government and the Chambre des Notaires), so you can check everything before you sign.

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What Is a Compromis de Vente?

A compromis de vente is a private written agreement in which the seller commits to sell and the buyer commits to buy a specific property at a specific price. It is usually signed once the price is agreed, before the deed is signed at the notary’s office.

Article 1589 of the Luxembourg Civil Code says that a promise of sale is a sale when both parties agree on the property and the price. That is why guichet.lu, the government’s information portal, describes a compromis signed by both parties as final and binding: “compromis de vente vaut vente”. For it to be valid, both parties must have the legal capacity to sell and buy, and the property and the price must be clearly determined.

A compromis is not compulsory, but in practice almost everyone signs one to fix the agreement while the deed is prepared.

Why you still need a notary

Only a notary can draw up the deed by which a property changes owner, and only that deed can be transcribed at the mortgage registry, which makes the sale enforceable against third parties. Before the deed, the notary checks that the seller really owns the property and whether there are mortgages, easements or other charges.

Who Prepares It, and Who Chooses the Notary?

Because the compromis is a private agreement, the law does not reserve it to the notary. It can be signed by the parties themselves or by their representatives — guichet.lu gives the example of a duly mandated estate agent. When an agent is involved, the agent often prepares the draft; you can also ask a notary or a lawyer to prepare or review it.

For the deed, the parties can choose any notary in the country, wherever the property is. If the compromis names none, the party paying the notary’s fees — in practice the buyer — usually chooses.

The Clauses That Matter

At a minimum, guichet.lu lists the names and addresses of the parties, the description of the property (cadastral references), the price and the payment terms. Most compromis also give the planned date of the deed and of the handover of the keys, the notary, and any easements. For an apartment, the Chambre des Notaires adds the share of the common parts and the usable surfaces.

The loan condition (condition suspensive)

With this clause, the buyer only has to buy if a bank grants the mortgage. The parties set a written deadline for the bank’s answer; guichet.lu notes that in practice it is at least 4 to 6 weeks, and that it can be extended with an official bank letter confirming the application is in progress. It is not a free exit: in a dispute, the buyer must prove they applied to at least one bank in time and informed the seller within the deadline.

The penalty clause (clause pénale)

A fixed amount owed by the party who breaks the agreement without a valid reason. According to guichet.lu it is set in practice at 10% of the price — €35,000 on a €350,000 sale. That 10% is custom, not a rate fixed by law.

Deposit or advance payment

For an existing property, I have found no legal rule setting a deposit at signature. Whether an advance is paid, how much, to whom and when it is refunded depends on what the compromis says — so read those lines closely.

Transfer of ownership

Because the sale is complete at signature, the Chambre des Notaires warns that ownership and risks can pass to the buyer from the compromis itself, even before the price is paid. It recommends a clause stating that ownership transfers only on the day of the notarial deed.

Can You Withdraw After Signing?

In principle, no. guichet.lu states that a signed compromis is binding and that you cannot, in principle, withdraw from it; it provides no cooling-off period for buying an existing home. Rules you may know from another country do not apply here.

If one party refuses to go ahead without a valid reason, the other can take legal action. The party at fault may owe the penalty clause or, if there is none, compensation for the damage actually caused. Your real protection is the conditions you write in before signing.

How Long Between the Compromis and the Deed?

There is no fixed legal period. The date depends on how long the bank needs to confirm the loan, on the notary’s checks and on the dates written into the compromis — the Chambre des Notaires lists its period of validity among the points it should contain. On the day, both parties sign before the notary and the price is paid as agreed; the deed is then registered and transcribed.

Registration, Duties and the Bëllegen Akt

Registering the compromis

In principle a compromis must be registered with the AED, within 3 months for a private individual according to guichet.lu. Many are not; that does not affect validity between the parties, but registration makes the compromis enforceable against third parties. With a suspensive condition, such as the loan condition, the fee is a fixed €12; without any, a proportional duty on the price is charged.

Duties on the deed

For an existing property the normal rate is 7% of the price: 6% registration duty and 1% transcription duty — €42,000 on €600,000 before any tax credit, plus the notary’s fees. Our notary fees calculator gives you an estimate.

The Bëllegen Akt tax credit

If you buy a home to live in, the Bëllegen Akt credit reduces those duties. The amount in force is €40,000 per person, made permanent by the Chamber of Deputies in June 2025. The notary applies for it in the deed; you must move in within 2 years (4 for a plot or a home under construction) and live there at least 2 years. The AED always charges a minimum of €100. In July 2026 the government announced an increase to €45,000 per person; until it is law, check guichet.lu or ask your notary. More in my article on the Bëllegen Akt.

Buying Off-Plan: The Reservation Contract

For a home still to be built (VEFA), the sale can be preceded by a reservation contract (contrat de réservation) and must be concluded by notarial deed. According to guichet.lu, the deposit cannot exceed 2% of the forecast price and is refunded if the seller does not conclude the sale in time or the final contract differs significantly — for example a price more than 5% above the forecast. The deed must include a completion guarantee, and you pay in instalments as the works progress.

What to Check Before Signing a Compromis

• The parties: every owner signs (both spouses, all heirs).
• The property: cadastral references, surfaces, cellar, parking and terraces as you understood them.
• Price and payment terms, including anything sold with the property.
• The loan condition: amount, deadline, how the bank’s answer is sent — confirmed as realistic with your bank.
• Other conditions you need, such as a building permit for planned works.
• The penalty clause: amount, and that it applies to both sides.
• Any advance payment: amount, who holds it, when it is returned.
• Transfer of ownership on the day of the deed.
• Dates: deadline for the deed, handover of the keys.
• The notary, named or agreed.
• The property’s situation: leases, easements, permits for past works, energy performance certificate and, for an apartment, condominium accounts and recent general-meeting minutes.

For the whole journey, see my step-by-step guide to buying in Luxembourg; if you are selling, read how to sell a property in Luxembourg.

Frequently Asked Questions

Is a compromis de vente binding in Luxembourg?

Yes. Under article 1589 of the Civil Code, a promise of sale is a sale once both parties agree on the property and the price, even before the notarial deed.

Can I cancel a compromis de vente?

In principle, no. You can only step back if a condition written into it is not met — for example, the bank refuses the loan within the deadline. Otherwise you may owe the penalty clause or damages.

Who drafts the compromis de vente?

It is a private agreement, so it need not be drafted by a notary. It is often prepared by the estate agent; a notary or lawyer can prepare or check it. The final deed is signed before a notary.

How long between the compromis and the notarial deed?

No fixed legal period: it depends on the bank, the notary and the dates set in the compromis.

Do I have to pay a deposit when I sign?

For an existing property, no legal rule sets one. Off-plan, the reservation deposit is capped at 2% of the forecast price.

This article is general information, not legal advice. Every sale is different: the notary is the reference for your own compromis and deed, and the official texts prevail.

Sources: guichet.lu — compromis de vente, buying a property to be built, Bëllegen Akt; AED guide on registering compromis (May 2025); Government of Luxembourg, releases of 25 June 2025 and 16 July 2026; Ministry of Housing and Chambre des Notaires, “Acquisition d’un logement – conseils pratiques” (2018); Civil Code, art. 1589.