How to read an MOT history before you buy

A used car advert tells you what the seller wants you to know. The MOT record tells you what a tester was obliged to write down, once a year, under threat of losing their licence to test. That makes it the most reliable document attached to most vehicles — and the one buyers read least carefully.

Start with the mileage column

Every test records the odometer reading. Read those numbers down the page before you look at anything else. The reading should climb by roughly the amount the vehicle was used each year, consistently, with no backwards steps and no suspiciously small increments. A reading that falls, or one that sits almost still for two years and then jumps, is the single strongest indicator that something about the history does not add up. The record will not accuse anyone — it just shows you the discontinuity and leaves you to ask about it.

Count the tests, not just the passes

A ten-year-old car should have roughly seven MOT tests on record. If it has four, ask where the others went. Gaps usually mean the vehicle was off the road, either voluntarily — stored, damaged, awaiting repair — or because it was not being used legally. Neither is automatically a reason to walk away, but a two-year absence from the record on a car described as a daily driver is a question with a specific answer, and you are entitled to hear it.

Read every advisory, in order

Advisories are where the money is. A single advisory for a tyre close to the limit is nothing. The same advisory for corroded brake pipes appearing in four consecutive years is a repair that was deferred four times, and it will fall due on your ownership rather than the previous one. Read them chronologically and look for repetition: repeating items describe deterioration in progress, while one-off items describe something that was noticed and dealt with.

Then check what the record cannot tell you

An MOT is a test of specific safety and emissions items on one day. It does not assess the engine, the clutch, the gearbox, or whether the car has outstanding finance against it. It says nothing about accident damage, recorded mileage fraud or theft. Treat the MOT record as the strongest single source you have, not as a complete history, and check the rest separately.

• Compare the mileage on the odometer with the latest test entry, in person.
• Ask why any gap in the record exists, and expect a specific answer.
• Price the repeated advisories into your offer before you negotiate.
• Run a finance, write-off and stolen-vehicle check separately — they are not in the MOT record.