Does a Failed MOT Devalue a Car? The Part of the Record Buyers Should Actually Read

A failed MOT stays on the public record for good, held against the car’s registration where any buyer can read it. There is no reliable figure for what that does to the price, and any percentage put on it is a guess. The fail is also the least useful part of an MOT history, and the two parts that tell a buyer most are the ones almost nobody checks.

Key takeaways:

• A recorded fail is permanent and public, and anyone can read it against the registration before they view the car.
• It is also ordinary. Nearly a quarter of all tests fail, and more than a third on cars aged 16 and over.
• Advisories and the mileage record tell a buyer more than the fail does, and both sit in the same free lookup.

What the Record Actually Shows

The MOT history is the one part of a used car’s past that neither the seller nor the buyer controls. It is written by the tester, held by the government and free for anyone to read.

Permanent, Public and Free

The history belongs to the registration, not the owner. It follows the car through every sale, and nothing a seller does can remove an entry from it.

Each test is recorded with its date, the mileage at the time, the result and the reasons behind it. A fail stays visible permanently, along with the defects that caused it, and so does the pass that followed once the work was done.

Reading it needs nothing but the registration number. The GOV.UK MOT history service shows the full record without the owner’s permission, so a buyer can see it before arranging a viewing, and many do.

That answers the literal question. A fail does not go away. Whether it costs the seller money is a separate question, and a harder one.

Nobody Can Tell You What It Costs

No reliable published figure exists for what a recorded fail does to a selling price. Any page quoting a percentage has made it up.

The reason is that the variables swamp it. The car’s age, its mileage, its condition on the day, how long ago the fail was, what the fault was and whether it was put right all move the price, and each one moves it far more than a line on a public record does.

A fail is priced in through the car rather than through the paperwork. A buyer looking at a car that failed on worn suspension two years ago is really asking whether the suspension is sound now, and the answer to that is under the car, not in the history.

That is why two cars with identical MOT records can sell for very different money. The record raises questions. The car in front of the buyer answers them.

Why a Fail Means Less Than Buyers Think

Before treating a fail as a warning sign, it is worth knowing how often one happens.

Almost a Quarter of Tests Fail

Our analysis of DVSA’s anonymised data covers 33,061,250 car MOTs carried out in 2024. Of those, 22.80 per cent failed, which is close to one car in four leaving the test with a fail certificate.

Age shifts the odds sharply. Cars under three years old failed 8.86 per cent of tests, and those aged 10 to 12 failed 27.78 per cent. On cars aged 16 or more, the failure rate reached 34.50 per cent, or more than one in three.

That changes how a single fail should be read. On a three-year-old car it is unusual and deserves a question. On a sixteen-year-old car it is closer to the base rate than to a verdict on how the car has been kept.

The reverse is worth noticing too. A long history of clean first-time passes on an old car runs against the odds. It can be the mark of a cherished car, and it is still worth asking how it was achieved.

And Some Fails Never Appear

A third result sits between pass and fail. Pass after rectification means the car arrived with a defect serious enough to fail, the test station put it right there and then, and the certificate records a pass.

In 2024 that happened on 5.48 per cent of tests, or 1,811,451 of them. Add those to the outright fails and 28.28 per cent of tests began in a condition that would have failed.

This is how the system is designed to work. A blown bulb replaced in the bay is a fault fixed, not a fault hidden, and the alternative is a fail certificate and a decision over whether the car can even leave.

It does mean a clean run of passes is not a record of a car that never turned up with a problem. A buyer treating one recorded fail as damning is judging that car against a standard the others in the history are not held to.

What Is Worth Reading Instead

Two parts of the same record carry far more information than the pass or fail line. Neither takes more than a minute to read.

The Advisory Pattern

Advisories are faults the tester saw that were not bad enough to fail the car. They are written on the certificate, handed to the owner, and stored on the record whether or not anything was done about them.

There were 34,857,066 advisory records against those 33 million tests in 2024, more than one per test on average. The most common were tread depth close to the limit on 16.06 per cent of tests, a brake disc or drum seriously weakened on 8.94 per cent, and a brake lining or pad worn below 1.5mm on 7.73 per cent. These are the same components that sit behind the faults that fail cars, caught a year earlier.

The pattern is what counts. One advisory is a warning given. The same advisory appearing year after year on the same component tells a buyer the owner was told repeatedly and chose not to act.

That says more about how a car has been kept than a single fail does. A fail followed by a clean retest shows a fault that was found and fixed. A recurring advisory shows one that was found and left.

The Mileage Record, and the Questions to Ask

Every test records the odometer reading, so the history is a dated sequence of mileages going back years. Laid end to end, those readings show how the car has been used.

That makes the record the cheapest mileage check a buyer has. A reading lower than the one before it, or a sudden change in annual mileage with no explanation, deserves a direct question to the seller.

It is a check, not a guarantee. The record shows what the odometer read on each test day, not what happened between them, so a consistent history supports the mileage without proving it. The record is also silent on whether a car has ever been written off, which is a separate marker worth checking before a viewing.

On any used car the MOT history is free, takes two minutes, and should be read before the viewing. Of everything in it, the fail is the part that deserves the least weight.