What Lex Koller means when selling property to a foreign buyer
Lex Koller — formally the Federal Act on the Acquisition of Real Estate by Persons Abroad (Bundesgesetz über den Erwerb von Grundstücken durch Personen im Ausland / Loi fédérale sur l'acquisition d'immeubles par des personnes à l'étranger, BewG/LFAIE) — is the Swiss law that restricts the purchase of residential real estate by non-residents. In practice, it does not ban foreign buyers outright, but it does require an authorisation for certain categories of buyer and certain types of property.
For a Swiss owner, this means that whether or not you can freely sell to a foreign purchaser depends on two questions: who the buyer is, and what kind of property you are selling. Get those two answers right, and most transactions are straightforward. Get them wrong, and the sale can be blocked, unwound, or in the worst case declared void by the courts.
Who counts as a "person abroad" under Lex Koller
The law does not classify people by nationality alone. It classifies them by residence and permit status.
The following buyers are generally treated as not being persons abroad, and can therefore buy without a Lex Koller authorisation:
- Swiss citizens, wherever they live.
- EU or EFTA nationals with an actual, effective domicile in Switzerland (typically holding a B, Ci or L permit), provided they will use the property as their primary residence.
- Third-country nationals (US, UK, Canadian, Australian, Indian, etc.) holding a C permit and resident in Switzerland.
The following buyers are treated as persons abroad and fall within the scope of Lex Koller:
- Any foreign national living outside Switzerland, regardless of nationality.
- Third-country nationals living in Switzerland on a B or L permit (they may buy a primary residence without authorisation, but a secondary or investment property triggers the rules).
- Foreign-controlled legal entities, or Swiss companies whose beneficial ownership sits abroad.
This last point matters more than many sellers realise: even a Swiss-registered company can qualify as a "person abroad" if its capital or voting rights are majority-held by non-residents.
Which properties are affected
Lex Koller focuses on residential real estate that is not the buyer's main home. Broadly:
- Primary residences are outside the scope. A foreign buyer who lives in Switzerland and will actually occupy the property as their principal home does not need authorisation, subject to some limits on size (typically up to around 3,000 m² of land).
- Holiday homes and serviced apartments in designated tourist zones are the classic Lex Koller case. These can be sold to non-residents, but only with a cantonal authorisation and within strict quotas.
- Pure investment residential property — a rental building or a buy-to-let apartment — cannot normally be sold to a non-resident foreign buyer at all. This is the hard stop that surprises many international investors.
- Commercial real estate (offices, retail, hotels, industrial and mixed-use buildings used for a genuine business activity) sits outside Lex Koller and can be sold freely to foreign buyers.
- Building land intended for residential development is treated like the residential category — restricted for non-residents.
A useful mental shortcut: Lex Koller is designed to prevent foreign capital from cornering the Swiss housing market and pushing up prices for residents. Wherever a transaction fits that concern, expect restrictions. Wherever it doesn't, the law tends to step aside.
The authorisation process step by step
Where a sale does require Lex Koller authorisation, the process is cantonal, not federal. Each canton has a designated authority — typically attached to the department of justice or the land registry — that reviews applications.
The typical sequence looks like this:
- Preliminary check. Before signing anything, the notary or your agent clarifies whether authorisation is required. If in doubt, a written ruling can be requested from the cantonal authority (a Feststellungsverfügung / décision de constatation).
- Purchase agreement with a suspensive condition. The notarised deed of sale is drafted subject to Lex Koller authorisation being granted. Without this clause, both parties are exposed if the application fails.
- Application to the cantonal authority. The buyer files the application, usually via the notary, providing proof of identity, permit status, intended use, financing structure and — for holiday homes — the property's classification within a tourist zone.
- Decision. The authority issues a ruling, generally within a few weeks to a few months. Cantons can attach conditions (for example, a minimum period of personal use, or a rental ban outside tourist seasons).
- Land register entry. Only once the authorisation is final and enforceable can the transfer be recorded in the land register (Grundbuch / registre foncier) and the sale completed.
For a resident foreign buyer purchasing a main home, none of this applies, and the sale proceeds like any other Swiss transaction.
Cantonal quotas for holiday homes
The federal government sets an annual quota of roughly 1,500 authorisations for the sale of holiday residences to non-residents, distributed among the cantons that have designated tourist zones. In practice, the bulk of these units go to a small number of cantons: Valais, Grisons, Vaud, Bern and Ticino take the largest shares, reflecting where non-resident demand actually concentrates.
Within each canton, individual municipalities are also subject to caps on the proportion of secondary residences (a legacy of the Lex Weber rules that overlay Lex Koller in tourist regions). If you own a chalet in Verbier, Zermatt, St. Moritz or Crans-Montana, the interaction of these two regimes shapes both who can buy and how many units can change hands in a given year.
A practical consequence for sellers: in years when a canton has already used its quota, an otherwise willing foreign buyer may have to wait for the next allocation. Timing matters.
What happens if Lex Koller is ignored
The sanctions are severe by Swiss standards. A transaction that should have required authorisation but did not obtain it is void — legally, it never happened. The land register entry can be reversed, the property can be forcibly re-sold at public auction, and the parties involved (including intermediaries who knowingly participated) risk criminal fines and prison sentences of up to three years.
Notaries and land registrars are on the front line here and are legally obliged to refuse to authenticate or register a transaction that raises Lex Koller concerns without proof of authorisation. This is the practical firewall that makes accidental breaches rare — but it also means that trying to structure around the law usually fails at the notary's desk.
Financing and practical implications for sellers
Beyond the legal framework, there are a few practical realities worth knowing before you accept an offer from a foreign purchaser.
Swiss banks apply their own restrictions on mortgage lending to non-residents, often requiring a higher down payment (typically 30–40% for holiday homes, sometimes more) and applying stricter affordability calculations. A signed offer from a non-resident buyer is worth verifying against the buyer's financing capacity earlier than usual, because financing gaps are a more common cause of failed transactions in this segment.
The timeline also stretches. A standard Swiss residential sale might close in eight to twelve weeks from signature. A Lex Koller sale involving a holiday home and cantonal authorisation often runs to four to six months, sometimes longer if the buyer's file needs clarification.
Finally, price expectations differ. Non-resident buyers of alpine and lakeside properties are generally less price-sensitive than local buyers, which supports valuations at the upper end. But because the pool of authorised buyers is capped, marketing needs to reach them — a strong online presence, English-language exposure and, where relevant, French, German and Italian coverage all matter.
How a specialised agency helps
Selling under Lex Koller is one of the situations where working with an agency that knows the process end-to-end is genuinely valuable. A good partner will screen buyers' status before you sign anything, coordinate with the notary on the suspensive conditions, and calibrate marketing to reach the pool of buyers who can actually complete. Neho combines the reach and digital tools of a national agency with a flat-fee structure that keeps the cost predictable — helpful when the transaction timeline itself is anything but.
Key takeaways
Selling Swiss property to a foreign buyer is entirely feasible in the majority of cases. Where the buyer is already resident in Switzerland and buying a primary home, Lex Koller is essentially invisible. Where the buyer is non-resident and the property is a holiday home, the sale is possible but sits inside a defined authorisation and quota system that adds time and complexity. Where the property is a pure residential investment and the buyer is non-resident, the sale generally cannot proceed at all.
For sellers, the two questions to settle before anything else are the buyer's status and the property's classification. Everything else — timing, price, marketing, notary work — flows from those answers.
