Index
What is considered a hidden defect for legal purposes
What law applies when the seller is a professional
What the buyer can demand: order matters
How long your legal exposure lasts
When you can defend yourself against a hidden defect claim
Real financial consequences: how much it can cost
What to do if you have already received a claim
How to avoid these situations before selling
Frequently asked questions
What is considered a hidden defect for legal purposes
Not just any breakdown that appears after the sale is a hidden defect in the legal sense. For a claim to have a basis, the defect must meet three conditions simultaneously.
First, it must be serious: it must prevent the normal use of the vehicle or significantly reduce it. A noise in the heating that does not affect driving does not have the same legal consideration as an engine that fails two months after purchase.
Second, it must pre-exist the sale: the problem must have existed before the vehicle was delivered, not occurred as a result of the buyer's subsequent use. If the buyer drives 15,000 km in three months without changing the oil and the engine fails, the fault is not pre-existing.
Third, it must be hidden at the time of inspection: it was not detectable with an ordinary inspection at the time of delivery. If the defect was visible and the buyer saw it or could have seen it, they cannot claim it as hidden.
The practical difficulty is that this third condition is subjective and frequently debated. An expert mechanic with a full diagnostic would have detected the problem, but an individual buyer with a visual inspection would not. This middle ground is where most disputes are fought.
What law applies when the seller is a professional
When the seller is a professional dealership or car trader and the buyer is an individual consumer, the hidden defects regime of the Civil Code (art. 1484 et seq.) does not apply, but rather the Recast Text of the General Law for the Defence of Consumers and Users (TRLGDCU), as amended by Royal Decree-Law 7/2021.
This distinction matters because consumer law is more demanding for the professional seller in several key aspects.
The most important: during the first year after delivery, any defects that appear are presumed to be pre-existing. This means that if the buyer detects a problem in the first twelve months, it is you who must prove that the problem did not exist at the time of sale, not them who has to prove that it did exist. It is a reversal of the burden of proof that puts the dealership on the defensive.
From the first year until the second, the presumption is reversed: the buyer must prove pre-existence. But if you have agreed in writing to a one-year warranty in the contract (the legal minimum for used vehicles), this second phase never applies.
If the buyer is a company and acquired the vehicle for its professional activity, consumer law does not apply: the contract terms govern. In that case, the warranty is whatever you agreed upon, and liability for hidden defects is governed by the Civil Code, with shorter timeframes and less demanding conditions for the seller. To understand the differences between legal and commercial warranties and how to structure them correctly, you can review the article on differences between legal warranty and commercial warranty in cars.
What the buyer can demand: order matters
Faced with a hidden defect, the buyer has four options and the law establishes an order that cannot be ignored.
The first option is the repair of the vehicle. The second is replacement with an equivalent vehicle. Only if repair or replacement are not possible, are disproportionate, or are not carried out within a reasonable timeframe, does the third option come into play: a price reduction. And only as a last resort, if none of the previous options resolve the problem, can contract termination and a refund of the money be requested.
The buyer cannot directly demand a refund of the money if the seller offers a repair and this is technically possible and not disproportionate in cost. This is a point that many dealerships are unaware of, and it can make the difference between paying for a £600 repair or refunding the full price of a £12,000 vehicle.
If the seller offers a repair and the buyer rejects it without a reasonable cause, demanding a refund directly, the seller has solid arguments to maintain their position. If the issue escalated to arbitration or the courts, the fact of having offered the repair and having been rejected without cause is a highly favourable element.
The period for the dealership to carry out the repair must be reasonable. Although the law does not define an exact number of days, more than 30–45 days for a standard repair starts to become difficult to justify. If the repair requires parts with long waiting times or complex technical intervention, this must be communicated clearly to the buyer and an alternative timeframe agreed in writing.
How long your legal exposure lasts
The legal warranty period for used vehicles is two years, but it can be reduced to one year by express agreement in writing in the contract. Most professional used car dealerships include this reduction explicitly, which limits exposure to twelve months.
If the contract does not mention anything about the warranty, the default two years apply. If it mentions "warranty: 1 year" without explaining that it is a reduction of the legal period, the clause could be deemed insufficiently clear and the courts may apply the two years anyway.
The buyer also has a period of two months from when they detected the defect to notify the seller. If they detect it in month five but communicate it in month nine, and the agreed warranty period was one year, the notification is still valid because the warranty period had not expired. But if they detect the defect in month ten and notify it in month thirteen, outside the warranty year, the claim has no basis even if the defect is real and serious.
When you can defend yourself against a hidden defect claim
Not every claim has a legal basis. You can reject a claim with a solid foundation in these cases.
The defect was declared in the purchase agreement or was visible during the prior inspection and the buyer signed their agreement regarding the vehicle's condition. If the contract describes the engine's condition as "having advanced wear due to mileage" and the engine fails two months later, the claim has much less backing than if the contract said nothing about the engine's condition.
The defect appeared as a result of the vehicle's use after delivery: lack of maintenance, improper driving, subsequent accident. In these cases, an expert technical report certifying the origin of the problem is the most effective tool.
The agreed warranty period has expired and the buyer cannot prove that the defect existed prior to delivery. From the second year onwards, the burden of proof is on the buyer, and if they cannot demonstrate pre-existence, the claim will not succeed.
The buyer is a company and the warranty terms agreed in the contract do not cover the claimed situation.
To understand how to structure the contract to protect the seller in these situations, you can review the guide on essential contracts in professional car sales.
Real financial consequences: how much it can cost
The cost of a hidden defect claim has two components: the direct cost of repair or refund, and the indirect cost of managing the conflict.
The direct cost depends on the nature of the defect. A standard mechanical breakdown (clutch replacement, gearbox repair) can range between £600 and £2,500. A serious engine or automatic gearbox failure can exceed £4,000. Contract termination with a full price refund wipes out the margin on the deal and can generate an additional loss if the vehicle has depreciated.
The indirect cost includes the time spent managing the claim (calls, visits to the workshop, written correspondence), the potential cost of a lawyer if the dispute escalates, and the impact on reputation if the customer leaves a negative review on Google or automotive portals.
That is why the first response to a well-founded claim should almost always be to offer a repair. In most cases, the cost of repairing is far lower than the cost of a refund and the cost of managing a prolonged conflict.
What to do if you have already received a claim
Do not ignore the claim. Ignoring a claim does not make it go away: it turns it into a formal complaint. A customer who receives silence or evasiveness has far more incentive to escalate the situation than one who is answered quickly and sensibly.
Review the vehicle's file before responding. Signed contract, description of condition at delivery, photographs, acceptance record, service history, and warranty coverage. With this information, you can evaluate whether the claim has any legal basis before committing yourself to anything.
Request a technical inspection of the vehicle. The technical diagnosis from a trusted workshop is the central element in determining whether the defect is pre-existing or post-delivery, and what its cause is. Without that diagnosis, any response is mere guesswork.
Always respond in writing. Even if the claim arrived by phone or in person, send your response by email or letter. This creates a record that you responded, what you proposed, and when you did so. In case the dispute escalates, that record is your first line of defence.
If the claim is well-founded, offer to repair it. It is the cheapest and fastest option to resolve the issue. If the customer accepts it, the conflict ends and can remain a salvageable bad experience. If they reject it, demanding a refund, you have arguments to maintain your position.
To understand the complete return management process and when the buyer does or does not have the right to return the vehicle, you can consult the guide on what to do if the customer wants to return the car.
How to avoid these situations before selling
The most efficient way to manage a hidden defect claim is to prevent it from happening in the first place.
Mechanical check-up before putting the car up for sale. A workshop inspection before listing the vehicle detects problems that could later turn into claims. If the problem is detected before the sale, you have three options: repair it, adjust the price, or describe it in the contract. All three are valid. What is not valid is ignoring it.
DGT and CARFAX reports before every purchase. A vehicle with undeclared accidents in its history or mileage discrepancies is a liability you assume at the moment of purchase. Checking the history before buying is the only way to avoid inheriting problems that are not yours. To understand how to use these reports as a purchase tool, you can review the article on how to know if a car has liens.
Purchase agreement with a description of the vehicle's condition. A contract that includes an accurate description of the car's condition, known defects, and a declaration of conformity signed by the buyer drastically reduces the universe of what can be claimed as "hidden". A defect described in the contract cannot, by definition, be hidden.
Signed delivery note with photographs. The date and photos of the vehicle's condition at the exact moment of delivery are the most direct proof that damage the buyer claims existed prior to purchase did not exist at that time. It is five minutes of work during delivery that can save months of conflict.
More than 750 dealerships already use Dealcar to manage their daily operations
Dealcar centralises the file of each vehicle from purchase to delivery: DGT and CARFAX reports, condition at the time of purchase, sales documentation, signed contract, and delivery note. With everything organised within the vehicle file, responding to a claim is a matter of opening the record, not searching for papers in folders.
If you want to see how it works, you can book a free demo at dealcar.io.
Frequently asked questions
Am I responsible for a hidden defect even if I didn't know the car had that problem?
Yes. As a professional seller, the law presumes that you should know the condition of the vehicle you are selling. Not having known about the problem does not automatically exempt you from liability. What can improve your position is proving that you carried out a documented prior inspection and that the defect was not detectable through that check.
Can the buyer demand their money back directly?
Only as a last resort. The law establishes an order: first repair or replacement, then a reduction of the price, and only if the previous options are not possible or are not executed within a reasonable timeframe, contract termination with a refund. If you offer a repair and it is possible and proportional, the buyer cannot directly demand a refund.
How long does the buyer have to make a claim?
If you have agreed to a one-year warranty in writing in the contract (the legal minimum for used vehicles), the exposure period is one year from delivery. If the contract does not specify anything, two years apply. The buyer also has a period of two months from when they detected the defect to notify the seller.
Does a "sold as seen, without warranty" clause in the contract protect me?
No. In sales to consumers, rights regarding hidden defects cannot be waived. The courts have systematically declared null and void any clauses that attempt to eliminate the legal warranty when the seller is a professional. What you can do is reduce the period to one year and describe the known defects in detail.
What is the difference between a hidden defect and normal wear and tear of the vehicle?
A hidden defect is a serious defect that existed at the time of sale and was not detectable during an ordinary inspection. Normal wear and tear is the expected degradation due to the use and age of the vehicle: wear on brakes, tyres, filters, or consumables are not hidden defects even if they require replacement shortly after purchase. The key lies in whether the problem pre-existed the sale or appeared due to subsequent use.
