A used car breaks down shortly after purchase – who has to prove the defect was already there?

A gearbox failure after four weeks, engine trouble after two months: often it is not the buyer who has to prove the defect existed at the point of sale – it is the dealer who has to prove the opposite.

You buy a used car, and a few weeks later the gearbox gives out, the engine starts smoking, or the electronics go haywire. The seller says: “Nothing to do with me – that only happened once it was in your hands.” And so begins a dispute in which the burden of proof is often shared out quite differently from what both sides first assume.

In short

If you bought the car as a consumer from a dealer, the law presumes that a defect which appears within one year of handover was already present at handover. It is the dealer who must rebut that presumption – you do not have to prove that the fault was there beforehand. Under settled, consumer-friendly case law from the highest courts, the presumption applies as soon as there is any cause at all falling within the seller’s sphere of responsibility – even where other explanations are also conceivable.

How I can help

• Checking whether the reversal of the burden of proof applies in your case (consumer sale, time limit, when the clock starts)
• Drafting the notice of defect and setting a deadline for the seller, so that your rights are not watered down
• Enforcing your right to repair, rescission of the contract, a price reduction or damages – through the courts if necessary
• Assessing whether a private seller can effectively rely on an exclusion of liability for defects
• Evaluating expert reports and any counter-report obtained by the seller

When the reversal of the burden of proof applies at all

The reversal of the burden of proof under § 477 BGB applies only to a consumer sale: you buy as a private individual and the seller is acting in the course of business – the classic example being the used-car dealer. If you buy privately from another private individual (for instance through a classified-ads platform), this provision does not apply, and a contractual exclusion of liability for defects is generally effective between private parties – unless the seller has fraudulently concealed the defect or expressly guaranteed particular characteristics.

It also matters what the presumption actually rests on: you first have to set out, and prove if it comes to a dispute, that a “deviation from the required condition” appeared within the time limit – in other words, that something on your car genuinely does not work as it should. Only then is it presumed that the underlying cause was already in place at handover. The reversal therefore concerns the timing of the cause, not the fact of the defect itself.

The time limit: one year from handover

Under § 477 BGB the presumption applies where the deviation shows itself within one year of the passing of risk – in practice, from the day you took delivery of the vehicle. If the fault only appears later, you as the buyer once again bear the full burden of proving that the defect already existed at the point of sale. This is a crucial distinction from the general limitation period for claims based on defects, which for movable goods is two years from delivery under § 438 BGB: that period governs how long you can bring claims at all. For used goods a business may shorten this limitation period to one year, but only by way of an express, separate agreement (§ 476 BGB) – and you must be specifically informed of it beforehand. A blanket clause buried in the small print is not enough.

How far the presumption reaches

Under the consumer-friendly case law of the highest courts, the reach of the presumption is now settled. In the past, buyers often came unstuck in court because sellers would point to several possible causes for the fault, and courts would then take the view that the presumption did not apply so long as it was unclear which cause was actually to blame. The courts have drawn a clear line against that approach: it is enough that, among the conceivable causes, there is at least one that falls within the seller’s sphere of responsibility. The fact that other causes not attributable to the seller are theoretically possible alongside it makes no difference. Only where the causes in question lie exclusively outside the seller’s sphere does the presumption fall away from the outset.

In practice this means the dealer cannot simply say, “it might have been down to the way the buyer drove it” – he has to establish that alternative cause so firmly that any cause on the seller’s side is ruled out. That is a considerably higher hurdle than many sellers have assumed until now.

The steps I take for you

1. Document the defect – workshop findings, photographs, the date it appeared. The closer to the handover date, the clearer the presumption.
2. A timely notice of defect to the seller, calling for supplementary performance (repair or replacement) and setting a reasonable deadline.
3. Reviewing the response: if the seller refuses, drags his feet or disputes the cause, we prepare to rescind the contract, reduce the purchase price or claim damages.
4. Securing the evidence: where the cause is in dispute, a technical expert report is usually obtained; I coordinate this and evaluate any counter-report.
5. Enforcement, out of court or – if it comes to it – before the competent local or regional court.

An example from practice

A client buys a used mid-range car with 60,000 km on the clock from a dealership. After five weeks the car comes to a standstill with a gearbox failure. The dealership points to “normal wear and tear” and to the possibility that the driver changed gear incorrectly. Because the damage appeared within one year of handover, and because the client is a consumer while the dealership is acting in the course of business, the presumption under § 477 BGB applies: it is assumed that the cause – pre-existing damage to the gearbox – was already present at handover. The dealership must prove that the client’s driving alone was to blame. A blanket assertion is not enough.

Common mistakes

• Waiting too long: report the fault only after several months and you risk the connection in time to the handover being disputed, or deadlines slipping by unused.
• Repairing without securing the evidence: if the vehicle is hastily repaired at any old garage, the documented finding as to the cause of the damage is often missing later on.
• Treating private sales like dealer purchases: with a private sale subject to an effective exclusion of liability, the reversal of the burden of proof does not apply – here what matters above all is whether there was fraudulent deception.
• Not demanding supplementary performance clearly enough: without a clear deadline and a precise description of the defect, the case drags on needlessly.

Frequently asked questions

Does the reversal of the burden of proof also apply to a private sale?

No. § 477 BGB applies only to a consumer sale, that is, where the seller is acting in the course of business. In a sale between private individuals you as the buyer generally bear the full burden of proof, and an agreed exclusion of liability for defects is usually effective.

Exactly how long does the time limit for the presumption run?

One year from the day the vehicle was handed over to you (the passing of risk). If the defect appears after that, you yourself must prove that the cause was already present at handover.

Can the dealer shorten the warranty on a used car?

Yes, to a minimum of one year, but only through an express, separate agreement that you were specifically informed of in advance – a hidden clause in the small print is not enough.

What if the dealer names several possible causes for the damage?

That alone is not enough, under the consumer-friendly case law of the highest courts, to defeat the presumption. As long as one of the conceivable causes falls within the seller’s sphere of responsibility, the presumption stands – the seller must establish an exclusively different cause.

Do I have to obtain an expert report before writing to the dealer?

Not necessarily, but it strengthens your position considerably to have the defect documented as early and as clearly as possible before you enter the dispute.

Your next step

A breakdown shortly after buying a car is a real nuisance, but your legal position is often far stronger than sellers would have you believe. To make sure the one-year window and the right approach to the evidence do not slip by to your disadvantage, you should act promptly. I will review your case in an initial consultation, place it in its proper legal context and enforce your claims against the seller – you can read more about my work in civil law at /en/topics/civil-law. Get in touch before you rush into a repair or let a deadline pass.

This is general information and not legal advice for an individual case.

This article provides general information and is no substitute for legal advice in an individual case. Last updated: 2026-08-10.

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