Every Used Car Buyer Needs Proof After Six Months and the Ombudsman Backed 52 Percent

• The Motor Ombudsman ruled fully or partly in the buyer’s favour in 52 percent of the used car purchase disputes it closed in 2025, and for the business in 40 percent.
• A fault that appears in the first six months is presumed to have been there at the sale, and after that the buyer must prove the car was faulty when it was handed over.
• Invoices, diagnostic reports and written correspondence are the evidence the Ombudsman’s decisions turn on, so the file starts in the first week.

What Happens to Your Claim the Day After Month Six

A used car that fails in its first six months starts the argument in the buyer’s favour. One that fails in month seven starts it in the seller’s favour. The Motor Ombudsman (TMO) analysed the used car purchase cases it decided between 2023 and 2025, and its data shows how far a buyer with a genuine fault can fall when the paperwork is missing.

The scale is large. TMO received 18,570 used car purchase cases in 2025, up from 10,262 in 2023, a rise of 81 percent in two years. They made up 40 percent of everything consumers brought to TMO that year, 18,570 of 46,092 new cases. Of the disputes closed in 2025, 52 percent went the buyer’s way in whole or in part, 40 percent went the business’s way and 8 percent of buyers withdrew. In 2023 the buyer figure was 60 percent, then 54 percent in 2024.

Buyers arrive expecting real money. The average sum they asked for was £8,007 in 2025, against £6,875 in 2023, a rise of £1,132 or 16.5 percent. TMO treats that as an opening expectation and no guarantee of an award.

The Typical Dispute Is an SUV Nearly Five Years Old

TMO’s profile of a typical case is an SUV, 4.7 years or 57 months old when the complaint reached the Ombudsman, with a petrol or diesel engine. A typical new car manufacturer warranty runs for three years, so the carmaker’s cover had usually expired by then.

SUVs were 51 percent of closed cases in 2025, against 19 percent of the 2025 car parc, which is 6,748,745 SUVs on SMMT figures. City cars and superminis are the reverse: 35 percent of the parc and 3 percent of the 2025 cases. TMO says the gap reflects demand, with more than 2.6 million new SUVs bought between late 2018 and 2024 now feeding the second hand market, and does not suggest SUVs have been more problematic than other body types.

Diesel overtook petrol in 2025. Diesel cars were 46 percent of disputes, up from 41 percent in 2023, while petrol fell from 48 percent to 40 percent. The ageing diesel fleet, the cost and complexity of emissions systems and long distance use are the factors TMO points to.

Customer service is the largest cause of complaint, at 57 percent of disputes on average and 64 percent in 2025. TMO files a car sold with a defect under that heading, as the dispute then turns on how well the seller inspected, prepared and described it. The list covers deposits not refunded, missing service history, undisclosed accident damage, misleading fuel figures and repairs left unfinished. Claimed defects present at the point of sale made up 35 percent of those customer service disputes in 2025.

How the Six Month Rule Works in the Consumer Rights Act 2015

The rule comes from section 19 of the Consumer Rights Act 2015, in force from 1 October 2015. Subsection 14 says goods that fail to conform to the contract at any point in the six months starting on the day they were delivered are taken not to have conformed on that day. The presumption applies to the right to repair or replacement, the right to a price reduction and the final right to reject, which subsections 3 and 4 list.

Subsection 15 gives the seller two ways out. The presumption falls away if it is established that the car did conform on delivery day, or if the presumption would clash with the kind of goods involved or with how they failed.

After month six the presumption is gone. TMO describes the position this way: the cause of the defect is generally taken to have arisen after the sale, and the buyer must prove it was inherent or linked to the condition of the car at handover. In every case the buyer still has the first job of showing that a defect exists.

Section 9 sets the standard: goods must be of satisfactory quality, meaning what a reasonable person would find satisfactory with the description, the price and the other circumstances in view. Durability is among the listed aspects. The term does not cover something the seller drew to the buyer’s attention before the contract, or something an examination before the contract ought to have revealed. Public statements about the car, including in advertising, count among the circumstances, so a saved copy of the advert is evidence.

The six months runs from delivery, so the delivery date belongs in the file. A buyer who collects a car on 3 March has until early September. The earlier right to return a car is covered in how to reject a faulty used car.

Three Cases, Three Outcomes

TMO published three decisions that show the line at work. Mr A bought a 10 month old executive car for £31,000. Four years later, at around 30,000 miles, the ABS unit failed and the repair was estimated at £3,150, about 10 percent of the price. He asked for a free repair as a manufacturing defect. The adjudicator ruled that the six months were long gone, which put the burden of proof on him. He had no records of an earlier ABS problem and no dealership returns, and had owned the car for years without raising any concern about the ABS. Nothing showed the fault was there at sale, the seller was cleared of breaching the Vehicle Sales Code and Mr A received no award.

The second case shows the six month rule working and the buyer still getting little. Ms B paid £10,000 for a four year old crossover SUV. A red warning light came on after three days and a faulty air filter was repaired. A few months later a water pump failure flooded the engine and it needed replacing. The seller refused a refund until it had been allowed to repair the car, and a warranty dispute with the manufacturer delayed the work. A new engine was fitted once that dispute ended, two months before she went to TMO. The adjudicator found a breach of the Vehicle Sales Code: the fault came inside six months, so the SUV was not of satisfactory quality at sale. The repair had already put the problem right, though, and a fault that has already been fixed gives no claim to a refund, a replacement or a rejection. The award was an apology.

The third case paid. Mr C bought a one year old hatchback from a franchise dealership. Around four years later, at roughly 41,300 miles, the car lost power and warning lights came on. A garage found the cambelt had stripped teeth. The dealer’s parts department called it a known issue with that model, the manufacturer refused a warranty claim, pointing to gaps in the franchised service record and a non genuine oil filter, and Mr C was quoted £15,750, more than he had paid for the car. The adjudicator started from the rule that the burden sat with him, then found it met. Both sides agreed the failure came from a design problem with the pulley cam drive, and the car had covered a little over half the manufacturer’s 75,000 mile interval. A free repair would normally be expected, but the cost exceeded what the car was worth, so Mr C was allowed to reject it and received a refund with a deduction for the mileage he had covered.

What to Do Now: Build the File Before You Need It

TMO’s advice to buyers is short: “For consumers, they highlight the importance of reporting faults quickly, retaining invoices, diagnostic reports and correspondence, and understanding how timing and evidence can affect the available remedies.”

Report the fault to the seller in writing on the day it appears, with the date, the mileage and the symptom. A written message puts a timestamp inside the six months. Keep chasing in writing as well, as a slow seller makes any dispute worse. TMO’s analysis of how retailers handle complaints found: “Delays, limited updates or uncertainty around responsibility can heighten the level of dissatisfaction, even where a remedy is ultimately provided.”

Get a diagnosis in writing from a garage and keep every invoice. The stripped cambelt teeth and the failed water pump were named causes, and the ABS claim had no record at all. Keep the advert, the sales invoice, the delivery date and the service history.

Expect the seller to ask for a repair. TMO describes it as the business’s one shot at a repair by law, and a free repair is the most common single award. A repair that works ends the claim for a refund, as Ms B found. A repair that costs more than the car is worth is a different position, which is how Mr C ended up with a rejection.

If the seller stalls or refuses, TMO runs a free alternative dispute resolution (ADR) service for complaints within the remit of the Vehicle Sales Code. TMO’s report says ADR rules give a business a maximum of eight weeks to conclude a complaint with a consumer, so the seller gets that window before the Ombudsman reviews the file.

TMO sets a standard for sellers too: “For used car retailers, the findings underline the value of thorough pre-sale checks, accurate vehicle descriptions, well-documented handovers and prompt aftersales communication.” A buyer can ask to see the checks and the handover documents before collecting the car. Complaints have been climbing for months, and used car complaints hit a record high in the summer.

What Comes Next as Hybrids and Electric Cars Reach Second Owners

Hybrid and electric cars were 6 percent of used car disputes in 2023 and 14 percent in 2025. In TMO’s words: “The rising presence of hybrid and electric vehicle disputes, points to a used car market that is becoming more technically complex. As more electrified vehicles enter second ownership, disputes may increasingly involve higher-value components, software-led diagnostics, charging systems and battery-related concerns.”

Complaints already on file include vehicles not charging and batteries not holding charge. TMO adds: “This reinforces the need for retailers to maintain clear records, robust preparation processes and transparent explanations of vehicle condition at the point of sale.” For the buyer, that makes the handover records the first thing to ask for on any electrified car.

Whatever the car runs on, the first six months are when the law works for the buyer, and the file kept in them decides the position in month seven and beyond. The Ombudsman’s caseload was already climbing, as the rise in Motor Ombudsman disputes covered earlier this autumn showed.

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Sources

• The Motor Ombudsman: Used Car Purchase Disputes, Trends, Drivers and Outcomes 2023-2025
• legislation.gov.uk: Consumer Rights Act 2015, section 19
• legislation.gov.uk: Consumer Rights Act 2015, section 9
• Motor Trader: Clear dealer communication plays key role in used car disputes says Motor Ombudsman

Reviewed by Preetam Gadekar