MOT Failure and Pass Grades Explained in Plain English

Written by the MOT Check Now editorial team and checked against GOV.UK and DVSA guidance. Last updated 3 November 2026. Read our editorial policy and how we get our data.

Every fault a tester records at an MOT is given a grade, and that grade decides whether your vehicle passes or fails, whether you can drive it away, and how urgently the problem needs attention. The MOT defect categories have been in use since 20 May 2018 and are: dangerous, major, minor, advisory, and a related result called pass after rectification, usually shortened to PRS. This guide explains each one, what the official definitions say, how the grades show up on a certificate and in a vehicle’s online history, and what to do when you see them. It is written for owners deciding what to do after a test and for buyers reading a car’s past results.

Key facts at a glance

The categories at a glance

A vehicle with only minor defects passes, and a certificate is issued. A vehicle with any major or dangerous defect fails. The full wording sits in the official MOT inspection manual for cars and passenger vehicles, published by DVSA on GOV.UK. MOT Check Now is an independent service and is not part of DVSA, DVLA or GOV.UK, so the manual and the GOV.UK pages are always the final word.

Why the grading system exists

The grades separate faults by how serious they are, so that the owner, the next owner and anyone reading the record can tell a trivial failure from a hazard. They also put the legal position in writing. A dangerous defect tells the keeper in plain terms that the vehicle must not go back on the road until it is repaired.

The same change introduced stricter checks on some items. According to the GOV.UK announcement of the May 2018 changes, testers began to fail diesel cars with a diesel particulate filter that show smoke of any colour from the exhaust, or where there is evidence the filter has been tampered with, as a major defect. Other items added or tightened at that time include obviously underinflated tyres, contaminated brake fluid, fluid leaks that pose an environmental risk, brake pad warning lights, and missing brake pads or discs. Reversing lights and headlight washers (where fitted) became part of the test for vehicles first used from 1 September 2009, and daytime running lights for vehicles first used from 1 March 2018. These items matter because each can produce a defect in one of the grades below.

How a tester decides which grade applies

The tester works through the inspection manual, which lists the reasons for rejection for each part of the car. For every item the manual says what condition is acceptable, and what condition counts as a defect. When a part falls short, the tester decides how serious the shortfall is and records it in one of the grades. A part that is only slightly below the standard is a minor defect or an advisory. A part that clearly fails the standard is major. A part that has failed so badly that driving is an immediate hazard is dangerous.

The grade describes the item on the day it was inspected, so a worn brake pad recorded as an advisory in March can be a major defect in November if it keeps wearing. There is also judgement at the margins, because two testers can describe the same condition in different words. Read the category and the tester’s text together, and never treat a single advisory as a verdict on a car.

Dangerous defects

A dangerous defect is one that is a direct and immediate risk to road safety or has a serious impact on the environment. It is a fail, and the vehicle must never be driven. That applies whether or not you have a valid MOT. Even if your existing certificate has months left, driving a vehicle with a dangerous defect is illegal. GOV.UK puts the instruction simply: do not drive the vehicle until it has been repaired.

The penalties are serious: a fine of up to £2,500, a driving ban and 3 penalty points. In practice this means you should arrange for the vehicle to be repaired where it is, or recovered, and not driven on the road. Our guide to what to do after a failed MOT goes through the choices, including how to handle the situation if the vehicle is at the garage.

The DVSA inspection manual grades tread depth below the legal minimum as dangerous, as well as a tyre bulge or tear that shows cords, and more than one loose or missing wheel nut. Other illustrative examples of the kind of fault that may be graded dangerous include a brake pipe that is so corroded it is likely to fail, or a steering component that has separated. The exact wording differs between testers and the grade depends on the severity of the individual fault.

What a dangerous defect means for the next few hours

1. Ask the tester or the garage to explain the defect and show you where it is.
2. Do not drive the vehicle off the premises, even if you have months left on the old certificate.
3. Ask the garage for a written quote to repair it, or arrange recovery to a place of your choice.
4. Keep the failure document. It lists the defects and is the record you need for any retest or complaint.
5. Do not use the vehicle again on the road until the repair is complete and the vehicle has passed a retest.

Major defects

A major defect is a fault that may prejudice the safety of the vehicle, have an impact on the environment, put other road users at risk, or amount to another significant non-compliance. A major defect is also a fail. Unlike a dangerous defect, the car can in some cases be driven away if your current MOT is still valid and no dangerous defect was listed. In that situation, you would still be responsible for driving a vehicle in a safe state, so the sensible course is to repair it promptly.

Common examples include a tyre cut that reaches the cords, a tyre pressure monitoring system fault, a missing mirror, one loose or missing wheel nut, a failed light, a corroded structure near key mounting points and worn brake components. For the typical reasons cars fail, see MOT failure reasons.

If the MOT has already expired and the car fails with a major defect, you should not drive it except to a pre-booked repair or retest. Driving without a valid MOT can lead to a fine of up to £1,000, with the exceptions of driving to or from a repair, or to a pre-arranged test. Read driving without an MOT for the full position.

A major defect found while the old certificate is still valid is a useful early warning. It gives you the remaining days in which to repair and retest. The main risk is leaving the work until the certificate runs out.

Minor defects

A minor defect is one that has no significant effect on the safety of the vehicle or on the environment, plus other minor non-compliances. A vehicle with only minor defects passes. They are still worth fixing, because they tell you that something is not as it should be, and left alone they can become advisories or major defects at the next test. GOV.UK advises that minor defects should be repaired as soon as possible. They are recorded on the certificate and in the vehicle’s history.

Illustrative examples are a dim number plate lamp or a small exhaust blow that does not affect the emissions reading. A long list of minors on an older vehicle tells a buyer something about how much small-scale attention the car has had.

Advisories

An advisory is a note about a component that is not yet defective but could become more serious in the future. It is a pass, and it is the tester’s way of telling you what to watch. GOV.UK describes advisories as items to monitor and repair if needed. Advisories are applied where an item has not deteriorated enough to justify rejection, which is why they involve judgement and why different testers may note different items on the same car.

The practical advice is to take advisories seriously without panicking. Ask for a quote on the item, plan for the repair, and check it before the next test. A repeated advisory across several years is a signal that a problem is developing slowly, or that it was never repaired. Our guide to MOT advisories explained covers this in depth, and the free advisory tracker helps you follow how a car’s advisories change from one test to the next.

Pass after rectification (PRS)

PRS means the vehicle had a defect that was fixed at the test centre during the test and then rechecked, so it passes. It appears in the DVSA data against the item, so a car’s history may show a defect that was corrected on the day. A PRS entry does not mean a car failed overall, but it does show that something needed fixing before the vehicle met the standard. Several PRS entries for similar items across years can show that a part keeps needing attention.

The usual PRS examples are quick fixes: a blown bulb replaced while the owner waits, a wiper blade swapped, a tyre pressure corrected. A PRS entry for a brake component or a structural repair is a more significant event, since it means a safety-relevant part was repaired during the visit.

Pass and fail: the overall result

A pass or a fail is the overall outcome, and not a defect category. A pass means the vehicle had no major or dangerous defects at the time. It can still come with minor defects and advisories listed. A pass does not mean the vehicle is free of problems, and it is not a statement about the engine, clutch or gearbox, which are not tested. See what is an MOT for what the test does and does not do. A fail means at least one major or dangerous defect was found, and a failure document lists them.

Worked examples

The examples below are invented to show how the grades combine. They are not records of real vehicles.

Illustrative example 1: a pass with one advisory and one minor

A car is tested with three weeks left on its old certificate. The tester records a worn front tyre close to the legal limit as an advisory and a dim number plate lamp as a minor defect. There are no major or dangerous defects, so the car passes. The owner should get a price for the tyre and fit it before it reaches the limit, and replace the lamp bulb soon.

Illustrative example 2: a fail on a major defect with the old MOT still valid

A car is tested ten days before its certificate expires and fails on a headlamp that is aimed too high, recorded as a major defect. No dangerous defect is listed, so the owner may drive home because the old MOT is still valid. The owner leaves the car at the test centre for the repair on the next day, and the item is retested within 10 working days, which qualifies for a free partial retest. The car passes and a new certificate is issued.

Illustrative example 3: a dangerous defect with months of MOT left

A car is tested early, with five months left on its existing certificate. The tester records a corroded brake pipe as a dangerous defect. The valid old certificate does not help: the car must not be driven on the road. The owner arranges recovery to a repairer, has the pipe replaced, and brings the car back for a retest.

Illustrative example 4: PRS on the day

A car arrives with a blown brake light bulb. The tester records the defect, the garage fits a new bulb during the appointment, and the tester rechecks it. The result is a pass with a PRS entry against the light. The history shows the item was fixed on the day. One PRS for a bulb is not a concern, though a pattern of similar entries in several years may show an owner who leaves small faults until the test.

Can you drive after a failed MOT?

The answer depends on two questions: is the old MOT still valid, and was a dangerous defect listed? The table sets out the combinations.

Remember that a valid certificate does not turn a faulty vehicle into a legal one. If you drive a car you know is in a dangerous state, the penalties for a dangerous defect can apply whatever the date on the certificate.

What to do when you see each grade

1. Dangerous. Do not drive the vehicle. Arrange a repair on site or recovery.
2. Major. Repair before further use. Check whether your current MOT is valid and no dangerous defect was listed before deciding whether it can be driven to a repairer.
3. Minor. Plan the repair. It is not urgent in the way a fail is, but do not ignore it.
4. Advisory. Get a quote, keep an eye on it and check it before the next test.
5. PRS. Note the item, since it needed work, and watch for repeats.

Retests and fees after a fail

If the vehicle fails, the retest rules depend on where the repair is done and how quickly the car comes back. A partial retest is free if the car is left at the test centre for repair and retested within 10 working days. A reduced fee applies if it is taken away for repair and returned within 10 working days. A free retest is available for a limited list of items, such as lights, mirrors, doors, seatbelts and wipers, if it returns to the same centre by the end of the next working day. Otherwise the full fee applies. The fee table is in MOT test costs.

The government sets a maximum fee. For a car with up to eight passenger seats it is £54.85, no VAT is charged, and a garage may charge less. The cap covers the test only, and repairs are priced separately. Get quotes for the items on the failure document before you choose where the work is done.

Challenging a result

If you believe a tester has made a mistake, you can appeal to DVSA. For a failed vehicle, the complaint form must be sent within 14 working days. Ask the garage for the failure document and keep it, along with any photographs or repair invoices, in case you need them. The appeal process and the forms are on GOV.UK, and the steps should be followed exactly as set out there.

A disagreement over an advisory is a different matter. An advisory does not change the result, so there is usually nothing to appeal. If you think an advisory is wrong, you can ask the tester to show you the item, or have the part looked at by another garage and keep the invoice if work is done.

How the grades show up in a vehicle’s history

The DVSA records each defect with its type and the tester’s text. When you look at a vehicle’s history, you will see entries labelled dangerous, major, minor, advisory or PRS. Reading them together tells a story. A major defect that appears once and is followed by a pass is a normal repair. An advisory that appears in three consecutive years suggests something worth asking the seller about. Use the MOT history tool to see these entries, and how to read an MOT history for a way of working through them.

Each test also carries a test result, an expiry date, an odometer reading and the unit it was recorded in, which helps you place a defect in time. For a deeper look at mileage readings alongside the defects, use the mileage check.

What our free tools show, and what they cannot

Our paid Full Vehicle Report costs £3.99 and adds a PDF with the full MOT timeline, a mileage chart and analysis, advisories that kept recurring, tax and MOT details and a plain-English risk summary. It uses the same official sources as the free tools, and it does not add finance, stolen or write-off data. To see how the data is sourced, read how we get our data.

Using the grades when you buy a used car

Defect grades are one of the most practical pieces of evidence in a used car purchase. Start with the MOT check to see the current status and expiry date, then open the full history and read each test from the oldest to the newest.

• A fail followed quickly by a pass is normal. It shows a fault was found and fixed.
• Dangerous defects deserve a question. Ask what was repaired, who did the work and whether there is an invoice.
• Many different minor defects on a young car can point to neglect.
• The same advisory in successive years suggests a repair that never happened.
• Several PRS entries for similar items point to a car that is routinely fixed only at test time.

Combine the history with the physical checks in the used car checklist, and use the seller claim checker to compare an advert with the record. If you are weighing two cars, the compare cars tool puts their records side by side.

Common mistakes

• Treating a pass as a clean bill of health. A pass can carry minor defects and advisories.
• Ignoring advisories on brakes, tyres and steering. They are the items most likely to become failures, and they affect safety now.
• Assuming a valid MOT allows you to drive with a dangerous defect. It does not.
• Confusing a minor defect with an advisory. A minor defect is present now. An advisory is expected soon.
• Reading PRS as a fail. It is a pass with a defect fixed on the day.
• Waiting until the old MOT has expired before arranging the repair after a major fail.
• Throwing away the failure document before the retest.

Edge cases

The old certificate runs out while repairs are under way

If the repair takes longer than the old certificate has left, you can drive to or from the repair, or to a pre-arranged test, but not for ordinary journeys. See driving without an MOT for the legal position. Booking the test inside the early window, explained in how early you can get an MOT, leaves more time for repairs.

More than one defect in the same area

A single test can record several defects on the same system. A car may have a major defect on one brake component and an advisory on another. The overall result is a fail, and the failure document lists every item so you can quote for all of them at once.

Different wording for the same fault

The tester writes the text of each defect, so wording varies between garages and between years. Compare grades first and wording second.

Voluntary tests on exempt vehicles

Owners of vehicles that do not need an MOT can still take one voluntarily. The result is recorded in the same history, including any dangerous or major defects. See MOT exempt vehicles for which vehicles qualify.

Northern Ireland

Northern Ireland uses a separate system run by DVA, so those results do not appear in the DVSA history that GB tools read. See MOT in Northern Ireland.

Motorcycles and vans

The same grades apply across vehicle classes, though the items inspected differ. See MOT test classes, and use the motorcycle MOT check or van MOT check for those records.

Next steps

1. Look up the vehicle on the free MOT check to see its status and expiry date.
2. Open the MOT history to read past defects and their grades.
3. If a test failed, read what to do after a failed MOT and plan the retest.
4. To avoid a fail next time, follow how to prepare for an MOT and the MOT test checklist.
5. Set the free MOT reminder so you know when the next test is due.
6. Read about the certificate itself in MOT certificate.

Glossary

• Defect. A fault or non-compliance recorded by the tester against an item on the vehicle.
• Dangerous. The most serious grade. A direct and immediate risk to road safety or a serious environmental impact. A fail, and the vehicle must not be driven.
• Major. A fail grade for a defect that may affect safety, endanger others or harm the environment.
• Minor. A pass grade for a defect with no significant effect on safety or the environment.
• Advisory. A note on a component that could become more serious in the future. A pass.
• PRS. Pass after rectification. A defect was fixed during the test and rechecked.
• Failure document. The paperwork the garage gives you when a vehicle fails, listing the defects.
• Partial retest. A retest that checks only the failed items, with different fee rules depending on how quickly the car returns.
• DVSA. The Driver and Vehicle Standards Agency, which runs the MOT scheme in Great Britain.
• DVA. The Driver and Vehicle Agency, which runs the MOT scheme in Northern Ireland.
• Inspection manual. The official DVSA document that sets out what testers inspect and the reasons for rejection.

Sources and further reading

• GOV.UK, Getting an MOT, including the sections on test results and retests
• GOV.UK, MOT inspection manual for private passenger and light commercial vehicles (DVSA)
• GOV.UK, MOT changes from 20 May 2018 (DVSA news story)
• GOV.UK, MOT test fees
• GOV.UK, Check the MOT history of a vehicle

MOT Check Now is independent and is not affiliated with DVLA, DVSA, GOV.UK or any government body. Contains public sector information licensed under the Open Government Licence v3.0.