Modern digital odometers store mileage data in electronic modules within the car. Clocking tools, which cost as little as £30-50 online, connect to the car's OBD (On-Board Diagnostics) port and rewrite the stored mileage. The process takes minutes and leaves no physical trace.
This is why physical inspection alone is not enough. You need data-based verification.
1. CarCostCheck Free Mileage Analysis
The free CarCostCheck report analyses mileage readings from every MOT test since 2005. It plots the mileage progression year by year and flags:
- Mileage drops: If the recorded mileage decreases between tests, the odometer has been wound back
- Impossible changes: A car showing 10,000 miles per year that suddenly shows 2,000 miles in a year
- Pattern breaks: Inconsistencies in the rate of mileage accumulation that suggest tampering
- Missing data points: Gaps in the MOT record where readings should exist
This analysis is automatic and free. You just enter the reg plate and the report highlights any mileage concerns.
2. Government MOT History
The DVSA's check-mot.service.gov.uk shows raw mileage readings from each MOT test. You can manually compare the numbers year by year. However, you need to do the analysis yourself, and it shows no warnings or interpretation.
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While data checks are the most reliable way to spot clocking, physical signs can also help:
Wear That Does Not Match Mileage
- Pedals: Rubber pedal covers on a car claiming 20,000 miles should show minimal wear. Heavily worn or replaced pedals suggest higher real mileage.
- Steering wheel: Leather steering wheels show wear on the sides where hands grip. A shiny, worn wheel on a low-mileage car is a red flag.
- Driver's seat: The bolster (side) of the driver's seat shows wear from getting in and out. Significant wear with low claimed mileage is suspicious.
- Gear knob: Worn gear knob markings or a shiny surface suggest heavy use.
Service History Gaps
A car with genuinely low mileage should have a service history with mileage recorded at each stamp. If the service book is missing or has gaps, the mileage cannot be verified through that route.
Dashboard Warning Signs
- Check the dashboard for any scratching or marks around the instrument cluster, which might suggest it has been removed
- Misaligned or slightly different-coloured dashboard elements around the speedo
A car clocked from 80,000 to 40,000 miles might be overpriced by £2,000-4,000 or more. Beyond the purchase price, the real cost comes from:
- Parts wearing out sooner than expected (because the real mileage is much higher)
- Insurance being invalid (if you declared incorrect mileage based on the odometer)
- Lower resale value when the true mileage is eventually discovered
Can I check a car's mileage for free?
Yes. CarCostCheck's free report analyses MOT mileage readings year by year and automatically flags inconsistencies that suggest clocking.
How common is mileage clocking in the UK?
The RAC estimates around 2.3 million UK cars have been clocked. Digital odometers make it easy and cheap to do.
What are the signs of a clocked car?
Inconsistent MOT mileage records, excessive wear for claimed mileage, service history gaps, and prices that seem too good. CarCostCheck flags mileage anomalies automatically.
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Related reading: How to Check a Used Car Before Buying | HPI Check vs Free MOT History | Full Feature Comparison