Mileage discrepancy
Also known as: mileage anomaly, clocking, mileage tampering
A mileage discrepancy occurs when a UK vehicle's recorded mileage decreases between MOT tests or other records — the leading indicator that the odometer has been illegally tampered with.
Every UK MOT records the vehicle's mileage at the time of test. The DVSA stores these readings and exposes them through the MOT History API. If the mileage drops between consecutive tests — for example 88,000 in 2023, then 62,000 in 2024 — the odometer has been "clocked" by someone in between.
Clocking is illegal under the Consumer Protection from Unfair Trading Regulations 2008 in the UK, but it is widespread, particularly on high-mileage trade-in vehicles. Industry estimates suggest 5–7% of UK used cars have inconsistent mileage records.
DealerPricing's vehicle history check automatically flags mileage discrepancies by cross-checking every MOT reading. If a vehicle's recorded mileage shows any decrease at any point, the report highlights it in red.
Related terms
- MOT historyMOT history is the record of every annual MOT test a UK vehicle has had since 2005, including pass/fail status, mileage at each test, expiry dates, advisories and recorded defects.
- HPI checkAn HPI check is a UK vehicle history report that confirms whether a car is stolen, has outstanding finance, has been written off, has mileage discrepancy, or has had its plate, colour or keeper details changed.
- Vehicle provenanceVehicle provenance is the verified history of a UK vehicle's ownership, status and incidents — covering stolen markers, finance, write-offs, mileage, plate changes, and keeper history.