How to Spot Mileage Clocking Using Free MOT History
Every MOT test records the car's mileage at the time. Lined up in order, that history is one of the most reliable free signals you have against odometer fraud — if you read it the right way.
“Clocking” means winding a car's odometer back — physically or digitally — so it looks like it's covered fewer miles than it really has. It's a real problem in the UK used car market, and it's also one of the easier things to catch, because every MOT test since 2005 has its mileage reading published by the DVSA and is free to check for any registration.
A car's mileage should only ever go up between tests. If a later test shows a lower reading than an earlier one, something needs explaining — but not every drop means the same thing, and reading MOT history correctly means understanding two things testers deal with every day: units, and readability.
Not every drop is clocking
A drop of a handful of miles between two tests is almost always a tester typing 32,114 instead of 32,411 — a keying error, not fraud. Genuine odometer fraud moves the number by hundreds or thousands of miles, because clocking only makes financial sense in that range; nobody commits fraud to shave a car's odometer back by four miles. A responsible mileage check grades these differently instead of flashing the same red warning for both: a large, unexplained drop is the one worth walking away from or investigating hard, while a small one is worth a mental note at most.
Miles, kilometres, and unreadable dashes
Two things regularly trip up a naive mileage comparison. First, testers record the reading in whichever unit the dash shows — usually miles, sometimes kilometres, particularly on imported or newer digital-dash cars — and comparing a kilometre reading to a mile reading without converting first can turn a genuine gain into what looks like a huge rollback. Second, DVSA testers mark a reading as unreadable when a failed digital dash can't be read, or note that the vehicle has no odometer at all. Neither case is a real measurement, and feeding either into a mileage comparison risks accusing an honest seller of fraud over a dead dashboard light — not the seller's fault, and not evidence of anything.
Any mileage timeline you check should account for both — converting every reading to the same unit before comparing, and excluding tests the tester genuinely could not read, rather than treating a blank or an estimate as ground truth.
MotorFile's free mileage timeline does this automatically: every reading is normalised to miles, unreadable and no-odometer tests are excluded from the comparison, and a genuine drop is graded — a small one flagged as a likely tester typo, a large one flagged clearly as a discrepancy worth investigating. It's part of the free check, on every UK registration.
Frequently asked questions
What is mileage clocking?
Mileage clocking (or "odometer rollback") is winding a car's recorded mileage back to make it look less used — and therefore worth more — than it really is. It's illegal in the UK to sell a car without disclosing that its odometer has been tampered with, but proving it happened is exactly why MOT history matters.
Is checking MOT history for mileage really free?
Yes. Every UK MOT test result — including the mileage recorded at that test — is published by the DVSA and is free to look up for any registration, on MotorFile or via GOV.UK directly. There's no paywall on this data; it's a legal requirement for testers to submit it.
What counts as a suspicious mileage drop?
A genuine reduction between two consecutive tests — where both odometer readings were actually measured, not estimated — is always worth asking about. A small drop of a few miles is almost always a tester keying error (typing 32,114 instead of 32,411, for instance). A drop running into the hundreds or thousands of miles has no innocent explanation and should be treated as a serious red flag.
Can an MOT with no odometer reading mean fraud?
Not by itself. DVSA testers sometimes can't read a digital dash that's failed, and some vehicles genuinely have no odometer fitted. A test marked this way is correctly treated as a gap in the mileage timeline — not as a rollback, and not as a clean bill of health either. It simply isn't evidence either way.
Does a rising mileage timeline guarantee a car hasn't been clocked?
It's a strong, genuinely useful signal, but not an absolute guarantee — the only fraud-proof records are the readings actually submitted at each test. A steadily rising timeline with no gaps is about as good a signal as free, publicly available data can give you.
Check a car's mileage history for free
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