Between the moment a buyer says “yes” and the day the keys change hands, several weeks — sometimes months — pass, marked by precise legal steps. For a first-time seller, this process can feel opaque or even intimidating. Here, in order, is what actually happens between the initial offer and the signing at the notary’s office, and why each step matters.
The Purchase Offer: Where It All Begins
The process usually starts with a purchase offer, written or sometimes verbal, sent by the buyer through the agency. As soon as the seller accepts it in writing — even by a simple email or a signed “agreed” note — a legal commitment can already arise between the parties. This is why an offer should never be accepted lightly: under Belgian law, agreement on the property and the price is in principle enough to form a sale, even before the preliminary agreement is signed.
The Preliminary Agreement (“Compromis”): A Firm Commitment
The compromis (or private sale agreement) formalizes this understanding in a fuller document: price, deadlines, suspensive conditions, allocation of costs, condition of the property. Once both parties sign it, it constitutes a binding sale — you cannot simply change your mind afterward. Contrary to popular belief, there is no legal cooling-off period after signing a property compromis in Belgium, including in Brussels. The only legitimate way out is an unmet suspensive condition — most commonly the buyer’s mortgage being refused — or the discovery of a hidden defect or information the seller failed to disclose.
This is also why the checklist of mandatory documents (EPC certificate, electrical compliance certificate, soil status, urban planning information, etc.) should ideally be gathered before this signature: an incomplete file delays the compromis or weakens the seller’s position in negotiations.
Between the Compromis and the Deed: The Notary’s Work
Once the compromis is signed, the file goes to the notary — the buyer’s, the seller’s, or both if each party has their own (the fees stay the same either way, simply split between the two notaries). The notary then carries out a series of mandatory checks: searching for any mortgages or seizures on the property, verifying urban planning compliance, checking the cadastral situation, and, for co-owned buildings, requesting documents from the property manager (general assembly minutes, reserve fund status, charges statement).
This work takes time, which is why the notarial deed is typically signed two to four months after the compromis, rather than days later. Too short a timeframe leaves little room if a document is missing or an urban planning issue needs to be regularized.
The 4-Month Tax Deadline and Registration Duties
In Brussels, the buyer must pay registration duties amounting to 12.5% of the price (or the market value, if higher). These duties are normally due when the deed is registered, but a private compromis generally doesn’t need to be registered separately as long as the notarial deed is signed within four months of its signature — hence the “four months” benchmark notaries frequently cite.
For a first purchase of a sole, primary residence, buyers benefit in 2026 from a tax allowance that removes registration duties on the first €200,000 of the price — a saving of up to €25,000 — provided the property stays under the €600,000 threshold and certain residency conditions are met. It’s the buyer who benefits directly, but a well-informed buyer often negotiates with more confidence — a point your agent can use during viewings.
Signing Day: The Notarial Deed
On the day itself, seller, buyer, and notary (or notaries) meet to read and sign the notarial deed. The buyer pays the balance of the price plus fees, the notary carries out the transfer of ownership, and the keys are handed over — often on the spot, or on an agreed date if the seller needs extra time to vacate.
Worked example — selling a house in Ixelles:
- March 3: offer accepted by the seller
- March 20: compromis signed, 10% deposit paid
- March to May: the notary checks planning compliance, mortgage status, and co-ownership documents
- July 18: notarial deed signed (4 months after the compromis), balance paid, keys handed over
In Summary
- An accepted offer already commits both parties — never sign one lightly.
- The compromis constitutes a binding sale — there is no legal cooling-off right in Brussels.
- Two to four months typically separate the compromis from the notarial deed, while the notary completes its checks.
- Registration duties (12.5%) are due within 4 months; an allowance of up to €25,000 exists for a sole, primary residence.
- On signing day: balance paid, ownership transferred, keys handed over.
Selling smoothly in Brussels means anticipating every step, from the first agreement to the notarial signature. Contact GR-Properties (info@gr-properties.be) for a complete valuation.