Since 20 May 2018, every defect found at an MOT is put into one of three categories: dangerous, major or minor. Dangerous and major defects fail the test. Minor defects pass. Advisories sit outside the three categories: they are items the tester thinks you should keep an eye on, and they do not affect the result.
The category tells you two things: whether the car passed, and how urgently the fault needs fixing. When you are buying a used car, it also tells you how serious each item in its history was.
The four levels at a glance
| Category | Result | What you should do |
|---|---|---|
| Dangerous | Fail | Do not drive until repaired |
| Major | Fail | Repair immediately |
| Minor | Pass | Repair as soon as possible |
| Advisory | Pass | Monitor, repair if it gets worse |
Before May 2018 an MOT was simply a pass or a fail, with advisories noted on the certificate. Older entries in a car's history use that format, so you will not see categories on tests before that date.
Dangerous defects
A dangerous defect is a direct and immediate risk to road safety or has a serious impact on the environment. The car fails, and it must not be driven until the defect is repaired. That applies even if the previous MOT certificate still has time left on it.
Examples include a tyre with its cords exposed, or brakes so badly worn or damaged that they may not stop the car. Driving a car with a dangerous problem can lead to a fine of up to £2,500, a driving ban and 3 penalty points.
If your car is given a dangerous defect, the usual options are to have it repaired at the test station or to have it collected.
Check a car now
MOT history, tax, mileage and ULEZ. No sign-up.
Major defects
A major defect may affect the car's safety, put other road users at risk or harm the environment. The car fails and the defect should be repaired immediately.
Examples include a tyre with tread below the 1.6mm legal minimum, or a headlamp that does not work.
Whether you can drive the car away depends on your existing MOT:
- If the old certificate is still valid, you can drive the car away, as long as it is roadworthy and has no dangerous defects.
- If the old certificate has run out, you can only drive it to have the defects repaired, or to a pre-booked MOT test.
Either way, the car must meet the minimum standards of roadworthiness at all times. Driving without a valid MOT can lead to a fine of up to £1,000.
Minor defects
A minor defect has no significant effect on the safety of the car or on the environment, but it is still a fault. The car passes, and the defect is listed on the certificate so it can be repaired as soon as possible.
A washer that provides too little fluid is a typical example. Left alone, some minor defects become major ones by the next test, so they are worth fixing rather than ignoring.
Advisories
An advisory is not a defect category. It is a note from the tester about something that is not yet a fault but could become one: a tyre close to the legal limit, slight corrosion on a brake pipe, or a small oil leak. The car passes.
Advisories are some of the most useful lines in a car's history, because they show what was starting to wear and whether it was dealt with. Our guide to MOT advisories explains how to read them.
Pass after rectification (PRS)
Sometimes a car has defects at the test but they are fixed at the test station straight away, before the car leaves. The tester then records a pass after rectification at station, shown as PRS.
On the certificate and in the history, PRS counts as a pass, but the defects that were found are still recorded. That matters when you are buying. A PRS on a bulb tells you very little. A PRS on brakes or suspension tells you there was a fault serious enough to fail the car, and it is reasonable to ask for the invoice.
How the categories appear in a car's history
Our free MOT check lists every test since 2005, with the result, the mileage and each defect or advisory under its category. When you read it:
- Look at what failed, not just how often. A dangerous brake defect is a different story from a blown bulb.
- Follow items from year to year. An advisory that becomes a minor, then a major, shows a fault that was left until it had to be fixed.
- Check the gap between a fail and the next pass. A pass a few days later is normal. A long gap, or no pass at all before the car was sold, needs an explanation.
- Note any dangerous defects. A car that was driven with one may have been neglected in other ways.
Our guide to common MOT failures covers which items fail most often and roughly what each costs to fix. The MOT record covers roadworthiness only, so the £9.99 full history check adds finance, write-off and stolen records before you buy.
Common questions
Does a minor defect fail the MOT?
No. A car with minor defects passes. The defects are listed on the certificate and should be repaired as soon as possible, but they do not stop you getting an MOT.
Can I drive my car after it fails with a major defect?
Only if the previous MOT certificate is still valid and the car is roadworthy, or to have the defects fixed or to a pre-booked MOT test. If the old MOT has run out, those are the only journeys you can make.
Can I drive a car with a dangerous defect home from the test?
No. A car with a dangerous defect must not be driven until it has been repaired, even if the old MOT certificate has time left on it. Arrange for it to be repaired at the test station or collected.
What does PRS mean on an MOT history?
Pass after rectification at station. The car had defects at the test, they were fixed at the test station straight away, and it then passed. The history records the defects that were found, so you can still see what was wrong.
Written by James Parry. Last reviewed 11 November 2026 against the current DVSA MOT inspection manual. Contains public sector information licensed under the Open Government Licence v3.0.