A private sale comes down to one document that nobody really reads until something goes wrong. In Switzerland, no official form is mandatory: a contract written by hand on a sheet of A4 does the job, provided it describes the car, both parties and the terms of the exchange precisely. That is exactly where most documents fail. They tick boxes without describing anything. Here is what a sales contract needs to contain, item by item, and the wordings that create a feeling of safety while guaranteeing nothing.
What the contract settles, and what it does not
A contract is not worth anything because of its layout. It is worth what it describes. One precise page protects you better than a four-page form filled in halfway, with sections left blank and boxes ticked at random.
What the contract fixes:
- who is selling and who is buying, with no ambiguity about identity
- which vehicle exactly, down to the chassis number
- at what price, and by which means of payment
- in what known condition, including disclosed defects
- at what moment the car, the keys and the documents change hands
What it does not do, and you need to know this before relying on it. It does not replace an inspection report. It transfers neither the insurance nor the plates: those are separate steps, each to be handled on its own. And above all, it does not guarantee that the money reaches your account. A contract signed by a buyer who does not pay remains a sheet of paper. The mechanics of getting paid are a separate matter, and we covered them in the article on how to actually get paid. If you are still weighing up the selling route itself, the three ways to sell in Switzerland set out the framework before you draft anything at all.
Identifying the parties and the vehicle without approximation
For the people involved, take the details from the original identity document, not from a photo sent by messaging app. For both parties, not just for the buyer:
- full first name and surname
- full address
- date of birth
- type and number of the identity document presented
For the vehicle, the precision comes down to the chassis:
- make, model, exact version
- chassis number read off the vehicle, not copied from the advert
- plate number on the day of the sale
- date of first registration
- colour as it appears on the registration document
The chassis number is the only identifier that follows the car for its entire life. The plate does not: in Switzerland, plates belong to the holder and stay with the seller. A plate noted in the contract is therefore only a marker of the transaction, not an identification of the vehicle. And copying a chassis number from an advert is the kind of mistake that makes a contract useless on the day you need to prove which car you were talking about.
Mileage: one reading, one date, one time
Write down the exact odometer reading at the moment of handover, with the note "read on … at … hours". Not the figure from the advert published three weeks earlier. Not a rounded number.
This is the line that will later date every kilometre driven after the sale. Without it, a discussion about wear six months later becomes a question of memory, and the memories of the two parties will diverge.
If the advert said 112,000 km and the odometer shows 113,400 on the day of handover, that gets written down. One line is enough. What costs money is leaving the gap implicit and discovering it together in the car park.
One point deserves your attention before you sign: an odometer reading that matches neither the service book nor the invoices is not an administrative detail. The article on what you remain liable for after the sale tackles that question head on.
Price, payment and the moment the car changes hands
The amount is written in figures and in words, with the currency. The agreed method of payment appears in black and white. One sentence must state, without hedging, that keys and documents are handed over only once the funds have been credited and verified by the seller personally.
Three classic traps:
- the wording "price to be agreed", or the amount box left empty
- a deposit taken without the contract saying what happens to it if the buyer walks away
- silence on the moment of transfer
That last point is the one rushed contracts leave hanging. From when is the car the buyer's responsibility: at signature, at payment, at the handover of the keys? Do not assume an obvious rule applies. This is precisely what the contract has to settle, explicitly, in one sentence that both parties reread before signing.
Disclosed defects, named one by one
"The vehicle shows some normal wear" describes nothing. A list that names each item does:
- play in the steering, noticeable at low speed
- engine warning light coming on intermittently when cold
- chipped windscreen, outside the driver's field of vision
- air conditioning cooling weakly
- earlier damage to the front right wing, repaired, invoice no. … dated … handed to the buyer
The logic never changes. A disclosed defect is negotiated once, on the price. A discovered defect is paid for twice: on the price, then on trust, and the second time costs more. It is the same reasoning that sometimes makes it better to disclose a defect rather than repair it when the quote exceeds what the market will give back.
This list gets written while the buyer has the vehicle in front of them, bonnet open. Not in the evening, not over the phone the next day.
The inventory of what leaves with the car
One line per item, with quantities:
- number of keys handed over, including remotes
- service book
- invoices handed over, copy kept by the seller
- inspection report, with its date
- second set of wheels, tyres and rims specified
- boot cover, mats, first aid kit, warning vest, warning triangle
- charging cable and adapters for an electrified vehicle
- radio code or radio card
- accessories that were removed, and confirmation that the vehicle is returned to its original state
The rule is simple: whatever is not inventoried will be claimed later, and with no proof, the doubt favours whoever is claiming. A precise inventory saves you messages three weeks after the sale. It also works the other way round: a recent inspection report in the file carries all the more weight when it is listed in the contract with its date.
The wordings that protect nobody
Some phrases reassure the seller without describing anything:
- "sold as is", on its own, with no description of that condition
- "seen and test driven", with no mention of what was actually seen
- "no warranty" on a contract that says nothing about the vehicle
- a contract drawn up after the keys changed hands
- an amount left open
- no date and no time
- a single signed copy, kept by one party only
The point to remember: it is not the clause that protects you, it is the documented transaction. An exclusion sentence sitting on an empty contract does not make up for the absence of a description. On the real scope of a clause like that, the article on what you remain liable for after the sale does the analysis, and we are not repeating it here.
Two copies, signed by both parties
Two identical originals, signed by both parties, each keeps their own. Not a photocopy sent later.
On the day of handover, also take:
- dated photos of the vehicle from every angle, in daylight
- a photo of the odometer
- a photo of the cabin and of the emptied boot
Keep them with your copy of the contract. State in the contract that you are removing the plates, and tell your insurer about the sale: those are two steps the contract does not take care of for you.
And keep the sequence in the right order: contract signed, funds credited and verified, then keys. Never the other way round, never "let us sign, you take the car, and the transfer goes out tonight".
When you are no longer the one signing
One last case changes how everything above reads: the one where the seller named in the contract is no longer the owner of the vehicle. Depending on the arrangement chosen, a garage can appear as the seller in your place. That shifts two things at once, the question of defects after the sale and the question of collecting the money. The detail of the two possible arrangements is covered in the article on who signs as the seller in a sale on consignment.
If your situation does not fit neatly into the boxes above, vehicle still under a leasing agreement, joint ownership, an estate, a sale to a buyer living abroad, the best move is to ask us before you sign rather than improvising a clause.
