The Compromis de Vente in Luxembourg: 2026 Guide

The compromis de vente (preliminary sale agreement), also known as the promesse synallagmatique de vente, is the crucial step that legally binds seller and buyer in a Luxembourg property transaction. Unlike a simple purchase offer, it creates legal obligations for both parties. Here is everything you need to know before signing.

What is a compromis de vente in Luxembourg?

The compromis de vente (preliminary sale agreement) is a bilateral contract by which the seller undertakes to sell and the buyer to buy a property at an agreed price. In Luxembourg, it has the legal value of a sale from the moment it is signed, subject to any conditions suspensives (conditional clauses).

This document sets out the essential terms of the transaction:

• Identity of the parties (seller and buyer)
• Precise description of the property (address, cadastre, surface area)
• Sale price and payment terms
• Any conditions suspensives (conditional clauses)
• Deadline for signing the acte notarié (notarial deed)

Difference between the compromis and the acte notarié

The compromis de vente is a private agreement (signed between the parties), whereas the acte notarié (notarial deed), also called the authentic deed, is drawn up and signed before a notary. In Luxembourg, only the acte notarié allows the official transfer of ownership and registration in the land registry (registre foncier).

The compromis is generally signed 2 to 4 months before the acte notarié, leaving time to satisfy the conditions suspensives and to prepare the mandatory documents for the sale.

The essential clauses of the compromis

Conditions suspensives (conditional clauses)

Conditions suspensives are clauses that make the validity of the sale dependent on the occurrence of future events. The most common ones in Luxembourg are:

• Obtaining the mortgage: the buyer generally has 4 to 6 weeks to secure financing
• Absence of easements: verification that no servitude prevents normal use of the property
• Planning compliance: the property complies with the applicable urban planning rules
• Absence of mortgages: the property is free of any charges

If a condition suspensive is not met within the set deadline, the compromis is cancelled and the dépôt de garantie (security deposit) is returned to the buyer.

The dépôt de garantie (10% security deposit)

In Luxembourg, the buyer traditionally pays a dépôt de garantie (security deposit) of 10% of the sale price when signing the compromis. This sum is held by the notary in an escrow account (compte séquestre) until the authentic deed is signed.

If the buyer withdraws without justification, the seller may keep this deposit as compensation. Conversely, if the seller backs out, they must repay double the deposit.

The completion deadline

The compromis sets a maximum deadline for signing the acte notarié, generally between 3 and 6 months. This period allows for:

1. Satisfying the conditions suspensives
2. Preparation of the documents by the notary
3. Cadastral and mortgage checks
4. Obtaining the CPE (energy performance certificate) if needed

The role of the notary

Although the compromis can be signed without a notary, it is strongly recommended to involve a notary from this stage in Luxembourg. The notary:

• Checks the legal status of the property (cadastre, mortgages)
• Ensures the compromis complies with Luxembourg law
• Protects the interests of both parties impartially
• Manages the security deposit in an escrow account (compte séquestre)

To learn more about the tax aspects of selling, see our guide to the Bëllegen Akt.

Advice for sellers

• Prepare your documents in advance: title deed, energy performance certificate, plans, co-ownership minutes
• Limit the conditions suspensives: the more there are, the greater the risk of cancellation
• Set reasonable deadlines: too short and they stress the buyer, too long and they delay your plans
• Check the buyer's solvency: ask for a mortgage agreement in principle from the bank
• Compare agency commissions before signing a mandate

FAQ

Can you withdraw after signing a compromis in Luxembourg?

Unlike in France, there is no statutory cooling-off period in Luxembourg for residential property sales between private individuals. Once the compromis de vente is signed, both parties are legally bound, and pulling out unilaterally carries financial consequences. The only penalty-free way out is when a condition suspensive fails – for example, if the bank refuses the mortgage or an undisclosed mortgage is discovered on the property. If the buyer walks away without a valid reason, they typically forfeit their 10% dépôt de garantie; if the seller backs out, they usually owe double the deposit. In practice, this means you should be genuinely certain before signing and have the conditional clauses drafted carefully. A notary can structure the clauses so that legitimate exit routes, such as a financing condition, are clearly protected, which greatly reduces the risk of costly disputes later on.

Does the compromis de vente have to be signed before a notary?

No, the compromis can be signed as a private agreement between the parties, and it is fully binding even without a notary. However, in Luxembourg it is strongly recommended to involve a notary as early as the compromis stage in order to secure the transaction and avoid future disputes. The notary checks the land registry and cadastre, confirms whether any mortgages or easements exist, and ensures the conditions suspensives are precisely worded. The notary also holds the 10% security deposit in an escrow account (compte séquestre), so that no money passes directly between buyer and seller. Since a notary is required in any case for the later acte notarié, involving one from the outset usually adds little extra cost while significantly increasing legal certainty. For both buyers and sellers, this remains the safest approach to a Luxembourg property sale.

What happens if the buyer does not obtain their mortgage?

If the compromis contains a condition suspensive covering the mortgage and the bank refuses financing, the compromis is automatically cancelled by operation of law. The buyer recovers their 10% dépôt de garantie in full, and neither party owes the other any compensation. It is essential that this clause is properly drafted: it typically specifies a deadline of 4 to 6 weeks, a minimum loan amount, and a maximum interest rate. In practice, the buyer usually has to provide a written refusal letter from the bank to invoke the condition. If the financing clause is missing from the contract, however, the buyer is considered fully bound: if they cannot obtain the loan and cannot pay, they lose their 10% deposit. This clause is therefore indispensable for buyers, while sellers should insist on realistic deadlines to keep the sale moving forward.

How much does a compromis de vente cost in Luxembourg?

If the compromis is drawn up by a notary, drafting fees generally range between 500€ and 1,500€, depending on complexity. These fees are often folded into the overall costs of the later acte notarié, so there is rarely any genuine double charge. If the compromis is instead written up privately between the parties, no notary fees apply at that stage, but you lose the legal protection a notary provides. Keep in mind that the main cost block arises at the acte notarié in any case: registration and transcription duties (enregistrement and transcription) plus the notary's own fees, which are calculated on the sale price. The Bëllegen Akt can offset part of that registration tax as a tax credit. Given the modest additional cost and the significant gain in security, having a notary handle the compromis is worthwhile in the vast majority of cases.