MOT mileage history explained

At each MOT the tester records the odometer if they can read it. Lined up by date, those figures are the mileage history. They are a series of observations, not a certified distance the vehicle has travelled.

What gets stored

• Read: a number, in miles (MI) or kilometres (KM)
• Unreadable: the dial could not be read. No number is stored for that test
• No odometer: there was nothing to read. Some older vehicles, and some records, are like this

This site compares a reading with the previous one that was actually read, and only when both use the same unit. A change of unit is labelled instead of being turned into a false gap. A lower figure is described as lower. It is not labelled as tampering.

A normal pattern

Annual tests on a commuter car often climb by roughly the miles that car does in a year. The gap between tests is not the gap between years if the owner tested early or late. Two tests on one day, a fail and then a pass, usually show almost the same mileage. A difference of a mile or two there is the car moving between the lanes, not a story.

When the number falls

A later reading that is lower than an earlier one is a reason to ask questions. It is not, by itself, proof that the mileage was altered. Ordinary explanations include:

• The odometer was replaced and started again, or a digital cluster was swapped
• One test was recorded in miles and another in kilometres, and the unit flag does not match the dial
• A digit was written down wrongly on the day
• The earlier figure itself was wrong

Clocking, where someone winds the mileage back, also exists. A paper service history, old MOTs and invoices that agree with the higher figure are the useful evidence. A single dip in this list is a prompt to ask the seller, not a finding.

How far back it goes

The public history is not a birth-to-today log for every vehicle. GOV.UK's check MOT history page describes the limits: results for cars, motorcycles and vans from tests since 2005, heavy vehicles from 2018, and Northern Ireland tests from 2017. Imported vehicles may have little or nothing before they were registered here. Confirm those limits on that page if you are making a decision.

What this page will not do

It will not estimate the "true" mileage, score the vehicle, or tell you whether to buy it. Use the figures beside a viewing, a service book, and the official check.