Guides
MOT guides
Plain-English explanations of the MOT rules that matter most when you are buying a car, keeping one on the road or dealing with a failed test. Each guide is written from GOV.UK and DVSA guidance and links to its sources.
Failures and defects
What fails an MOT?
The official groups of parts checked at an MOT, how dangerous, major and minor defects decide the result, and what happens after a fail.
Expired MOT and legal driving
Is there an MOT grace period?
Why there is no 7-day or 14-day allowance once an MOT runs out, the narrow journeys that are still allowed, and the penalties for driving without one.
Where to start
Most questions about an MOT come from one of a few situations. Pick the one closest to yours and follow the order below; the lookup tools show the record for a specific vehicle, and the guides explain what the rules say about it.
- Buying a used car. Start with the MOT history check for the full record, then read what fails an MOT to understand the defect levels it lists.
- Your MOT is due soon. Confirm the date with the MOT expiry check, then read the grace period guide so you know there are no extra days once it runs out.
- Your car has just failed. Read what fails an MOT for what each defect level means, then the section on driving after a failed MOT.
- Checking recorded mileage. Use the mileage check, and see the methodology page for how readings are compared.
About these guides
The guides describe the general rules for vehicles tested in Great Britain. Northern Ireland runs a different testing system, and some vehicles are exempt, so each guide notes where its scope ends. Every guide shows the date it was last reviewed and links to the official pages it relies on, so you can check the current wording yourself.
They are general information rather than legal advice, and they do not replace an inspection by a qualified mechanic. If something in a guide looks out of date, the Contact page explains how to tell us.