1 in 420 Used Car Buyers Complained to the Motor Ombudsman in 2025

• Used car complaints to The Motor Ombudsman rose 14 percent in 2025, hitting 18,570 cases compared with 16,317 the year before.
• Nearly eight million second-hand cars changed hands in the UK last year, so disputes still touched only 1 in 420 sales, though that is up from 1 in 468 in 2024.
• Poor customer service caused 40 percent of complaints and engine failures caused 35 percent, with cylinder head bolts, timing tensioners and oil pumps among the named faults.

The Motor Ombudsman Logged 18,570 Used Car Complaints as Disputes Outpaced Sales Growth

Buying a used car is still one of the biggest single purchases most UK households make outside a mortgage, and new figures from The Motor Ombudsman show more of those purchases are ending in a formal dispute. A report published by the ombudsman in February tracked every complaint brought against dealers accredited to its Vehicle Sales Code throughout 2025, and the volume rose 14 percent on the year before, climbing from 16,317 cases to 18,570.

The rise came as the used car market itself grew. The Society of Motor Manufacturers and Traders recorded around 7.8 million second-hand vehicle transactions in the UK last year, so the ombudsman’s own data shows complaints still cover a small slice of the overall market: roughly 0.2 percent of sales, or 1 in 420 cars. That figure has crept up from 1 in 468 in 2024, meaning the rate of disputes is rising faster than the market itself. A used car remains one of the few purchases a household makes without the statutory cooling-off period that applies to most goods bought at a distance, which is part of why the ombudsman’s figures are worth reading closely before anyone hands over a deposit.

Who a Used Car Dispute Actually Hits

The Motor Ombudsman only handles complaints against businesses accredited to one of its codes of practice, which covers a meaningful but not universal share of the UK’s used car retailers. Used cars made up 40 percent of every case the ombudsman opened in 2025, ahead of new car and warranty disputes, and nearly nine in ten Vehicle Sales Code complaints involved a second-hand model rather than a new one.

Two groups feel this most directly: buyers who pick up a car with an undeclared history, and buyers whose car develops a mechanical fault soon after handover. Bill Fennell, Chief Ombudsman and Managing Director of The Motor Ombudsman, said the rise reflected the sheer scale of the second-hand market rather than a collapse in standards, but he was blunt about where dealers were falling short. “What our data shows is that this is an area which many retailers fell down on before or after the consumer was handed the keys, meaning customer expectations were not met and dissatisfaction followed,” he said.

The Data Behind the Complaints

Customer service was the single biggest driver of disputes, accounting for 40 percent of cases. The ombudsman’s report ties this to buyers discovering undeclared modifications or an incomplete vehicle history after the sale, along with dealers failing to respond to queries once a problem surfaced.

Mechanical failures were close behind at 35 percent, and the specific faults named in the report read like a checklist for anyone about to view a used car: sheared cylinder head bolts, loosening timing tensioner pulleys, cracked engine blocks, seized crankshafts from failed oil pumps, and premature head gasket wear even on low-mileage examples. Bodywork and exterior issues accounted for 5 percent of disputes, covering everything from leaking panoramic roofs and windscreens to rust appearing shortly after a car changed hands. Fuel and emissions problems made up 4 percent, including blocked diesel particulate filters and failed fuel pumps, and electrical faults made up a further 4 percent, with buyers reporting intermittent locking issues and wiring faults that triggered airbag warnings. Tyres and brakes rounded out the list at 3 percent, with mismatched tyre sizes and warped discs among the complaints logged.

What It Costs a Buyer Who Gets It Wrong

A used car is rarely a small outlay, and a dispute over one often means months without reliable transport, repair bills running into hundreds or thousands of pounds, and a drawn-out complaint process before any resolution. The protection available to a buyer depends entirely on whether the dealer is accredited to a recognised code. The Motor Ombudsman is approved by the Chartered Trading Standards Institute and can step in to resolve a dispute with any business signed up to its Vehicle Sales Code, offering an alternative to the cost and stress of a small claims case. Buy from a dealer outside that scheme and a buyer’s main protections fall back on the Consumer Rights Act 2015, which still gives rights over faulty goods but without a free, independent ombudsman to enforce them.

The practical risk is that a buyer has no way of knowing which protection applies until something goes wrong, unless they check before they hand over any money.

How the Vehicle Sales Code Is Meant to Protect Buyers

The Vehicle Sales Code behind this year’s figures marked its tenth year in operation in September, and it sets out minimum standards dealers must meet on advertising, vehicle history checks and how complaints are handled once a sale has gone through. A business that signs up agrees to have its conduct measured against the code and to accept the outcome of independent arbitration if a dispute cannot be resolved directly with a customer. That gives a buyer a route to a binding resolution without going to court, and it gives a dealer a mark of accreditation it can use to stand out from competitors who have not signed up.

Not every used car dealer in the UK belongs to the scheme, and there is no legal requirement for one to join. That leaves a split market: buyers who deal with an accredited business have a clear, free complaints route if something goes wrong, and buyers who do not are relying on general consumer law and their own ability to pursue a claim through the small claims court if a dealer will not cooperate.

What to Do Before You Buy a Used Car

The single most useful step is checking whether a dealer is accredited to The Motor Ombudsman’s Vehicle Sales Code before agreeing to buy, using the ombudsman’s own business finder tool. Accreditation means a dealer has agreed to a minimum standard of conduct and that any dispute can go to independent arbitration rather than court.

Buyers should also ask for full service history and check for outstanding finance on the vehicle, as an unpaid finance agreement can leave a buyer without clear title to a car they have already paid for; Motoring Chronicle has previously set out how to check if a used car has outstanding finance before you buy. With the ombudsman’s own data on mechanical failures in mind, an independent inspection that includes a look at the cylinder head, timing components and oil pump is worth the cost on any car with a few years and some mileage on it, especially as buyers of older used cars are already paying more than they were a year ago.

Finally, get any promises made at the point of sale, including modifications, service history and outstanding warranty cover, in writing. Verbal assurances are the hardest thing to enforce once a dispute reaches an ombudsman or a court, and the report shows customer service failures, not just mechanical ones, are now the leading cause of complaints. A buyer who takes ten minutes to check accreditation, history and finance status before agreeing a price stands a far better chance of avoiding the kind of dispute logged in this year’s figures than one who relies on a dealer’s word alone.

Sources

The Motor Ombudsman, “TMO reports 14% rise in used car disputes in 2025”, published 17 February 2026: themotorombudsman.org