Between the offer to purchase, which commits you to little, and the deed of sale, which commits you to everything, Swiss law has an intermediate tier: preliminary contracts. The promise to sell is the best known of these — but it has two cousins that house-hunters constantly confuse: the option agreement and the right of pre-emption. Here is what each actually commits you to, when it is useful, and the golden rule that governs all three.
The golden rule: notarised, or void
A promise to sell relating to a property is only valid if executed in authenticated form — before a notary (art. 216 para. 2 CO). This is the clear answer to a frequent question: a “promise to sell between private individuals”, signed on the back of an envelope, has no legal validity whatsoever for a property. It thus differs from an offer to purchase, which organises the negotiation without concluding it — and it shares the logic of the final deed: whatever commits you on a property goes through the notary, everything else can be undone.
What the promise commits you to — and contains
The promise is a contract that obliges the parties to conclude the sale on the agreed terms: the parties, a precise description of the property, the price and terms of payment, conditions precedent — financing, permits —, the deadline for signing the final deed, and the fate of the deposit, often in the order of 10% of the price, held by the notary. To this are added the clauses that make the difference if something goes wrong: the contractual penalty — the compensation owed by the party who fails to perform — and, where applicable, a substitution clause allowing the buyer to be replaced. One clarification that will dispel a common confusion: the French rule whereby “the seller repays double the deposit” does not exist under Swiss law — here, only the sanctions provided for in the contract apply, and failing that, the general rules on non-performance.
When the promise is genuinely useful — and when it is unnecessary
A practitioner’s truth: in Geneva, most transactions do without a promise and go straight to the deed of sale, if necessary with conditions attached or a deferred transfer. The promise becomes necessary when an objective obstacle prevents signing the deed straight away, while the parties want to be bound: an LDTR authorisation to be obtained for a let flat, a plot subdivision in progress, a building permit awaited, an estate to be settled on the seller’s side — or a buyer who must first sell their own property. In these situations, it fixes the price and terms while the obstacle is being cleared. Outside these cases, it adds costs and a step without extra protection: an honest professional will tell you when you do not need it.
Withdrawing from a promise: what is possible
There are two very different exit routes. An unfulfilled condition precedent — financing refused within the deadline, a permit not granted: the promise lapses, without penalty, as that is precisely its mechanism. Pure withdrawal, however, comes at a cost: the agreed contractual penalty applies, the deposit may be forfeited according to the agreed terms, and the wronged party can even seek a court order for specific performance of the commitment — because a notarised promise obliges the parties to conclude. Hence the importance of negotiating the exit clauses before signing, with the same care as the sale contract itself, and of securing your financing before making the promise.
Option, pre-emption, redemption: the three cousins
Swiss law recognises three other agreements, all subject to authenticated form when they fix a price, and all capable of being annotated in the land register — which makes them enforceable against any subsequent purchaser. The option agreement gives the right to buy the property on fixed terms, for a maximum of ten years: it is the tool for operations that are being prepared — a developer securing a plot of land while obtaining a permit, a family organising a transfer of ownership. The right of pre-emption gives priority if the owner sells one day, for a maximum of twenty-five years: neighbours, co-owners or relatives use it so as not to be caught off guard. Redemption, rarer, allows the seller to buy back what they sold. Three distinct logics — reserving, having priority, returning — which annotation in the land register turns into solid rights.
Pre-emption: three months, and the clock starts from the moment you find out
The right of pre-emption is the one most often faced without having anticipated it, so its mechanics deserve to be known in detail. It is governed by articles 216c to 216e of the Code of Obligations, and it works in three stages.
What triggers it. The right can be invoked in the event of a sale of the property, but also “on the occasion of any other legal act economically equivalent to a sale”. It is therefore impossible to bypass a pre-emptor through dressing-up the transaction. Conversely, the law lists what is not a case of pre-emption: allocation to an heir in an estate division, forced sale, and acquisition for the performance of a public task.
Who must speak up. The obligation falls on the seller: they must inform the holders of the right of the conclusion of the contract and its content. Not merely the fact that they are selling — but the terms on which they are selling.
The deadline. The holder has three months to invoke their right, and this period starts running on the day they became aware of the conclusion of the contract and its content — not the day of signing. Once this period has elapsed, the right lapses. Another useful subtlety: unless otherwise agreed, these rights pass by inheritance but cannot be assigned. You can inherit a pre-emption right, but you cannot sell it on.
For a seller, the practical consequence is a timetable: as long as the information has not been given properly and in due form, the three-month clock has not started, and the buyer is not safe. This is a point the notary locks down — provided they have been told about the existence of the agreement in the first place.
From promise to deed
Once the promise has been signed and the deposit lodged, the timetable gets to work: fulfilment of the conditions, preparation of the final deed by the notary, then signature, payment of the balance, and registration in the land register — the moment of the actual transfer. If your transaction is considering a promise, the right question to ask first is: what obstacle justifies not going straight to the deed? The answer dictates the tool — and we work it out with you and the notary, case by case. Technical terms are in the glossary.