MOT Advisories Explained

An advisory is the most misunderstood line on an MOT certificate. It sits on a document that says "pass", it carries no legal obligation, and it is written in standardised technical language that gives no sense of urgency. As a result it gets ignored — which is unfortunate, because an advisory is the closest thing a car owner gets to a written warning from an independent inspector about what is going to cost money next.

This guide explains what an advisory is in the testing standard, how it differs from the other three defect grades, which advisories deserve immediate attention, and how to use them when reading a vehicle's history.

What an advisory actually is

An advisory is a note recorded by the tester about an item that is deteriorating, wearing, or otherwise worth monitoring, but which does not currently breach any testable requirement. Nothing has failed. Nothing is even formally defective. The tester is telling you that a component is on a trajectory.

Three characteristics define it:

• It does not affect the result. A vehicle with fifteen advisories and no defects passes exactly as cleanly as one with none.
• It is not a legal finding. Unlike a defect, an advisory does not correspond to a specific breach of the testing standard.
• It is permanent. Advisories are written to the vehicle's record and remain publicly visible for the life of the vehicle.

Advisories long predate the 2018 reform of the grading system. Testers have been recording advisory notices for years, which is why a car with a long history can show them stretching back well over a decade.

The wording is standardised. Testers draw on set phrases from the DVSA inspection manual rather than writing free prose, which is why you see the same formulations repeatedly: "nearing the legal limit", "slightly worn", "has slight play but not excessive", "corroded but not seriously weakened". Those qualifiers are doing real work. "Not excessive" and "not seriously weakened" are the exact phrases that separate an advisory from a major defect.

The four grades, and where advisories sit

Since May 2018 the test has recorded findings under four headings. The distinction between them is about severity and consequence, not about which part of the car is involved — the same worn ball joint can appear under three of the four depending on how bad it is.

The two failure grades are self-explanatory. The confusion is entirely at the bottom of the table, between minor and advisory, and it is worth pinning down properly. Our guide to dangerous, major and minor defects covers the failure grades in depth.

Advisory vs minor: the real difference

A minor defect is a genuine breach of a testable requirement that the tester has judged to have no significant safety effect. Something is wrong, measurably and by reference to the standard, but it is not wrong enough to fail.

An advisory is not a breach at all. Nothing has yet crossed a line.

In everyday terms the difference is thinner than the definitions suggest, and there is a degree of tester judgement in which label gets applied. Both mean the same thing to a sensible owner: someone who inspects cars for a living has looked at this component and thought it worth writing down.

How seriously to take an advisory

Not all advisories carry the same weight, and treating them as a uniform category is why they get ignored. A useful way to triage them is by how far the item is from a failure and what happens when it gets there.

Act on now — these are near-failures with a safety consequence:

• Tyres described as nearing the legal limit. Tread wears continuously, so a tyre advised in March may well be illegal by the autumn. The limit is 1.6mm across the central three-quarters of the tyre around its entire circumference, and the penalties for an illegal tyre are severe — up to £2,500 and three penalty points, per tyre.
• Brake pads or discs described as wearing thin. Braking performance degrades progressively and the failure mode is not gradual once a pad reaches its backing plate.
• Any advisory about corrosion near suspension mountings, seatbelt anchorages or the structure. Corrosion never improves and welded repairs get more expensive the longer they are left.
• Play in steering or suspension joints. These are graded on measured movement, so "slight play" is a specific distance from the threshold at which it becomes a major defect.

Plan for — likely to become a failure within a year or two:

• Slight oil, coolant or brake fluid seepage from a component.
• Exhaust noise or a minor blow that has not yet become a serious leak.
• Worn but functional shock absorbers, springs showing corrosion, and bushes with early play.
• Headlamp lenses that have begun to cloud or discolour, which eventually affects the beam pattern.

Note and monitor — genuinely low priority:

• Surface corrosion on non-structural panels.
• Minor windscreen chips outside the critical zones.
• Cosmetic damage that does not create a sharp edge.
• Items recorded on a spare wheel or on equipment that is not itself tested.

The distinction that matters most is between components that wear at a predictable rate and components that fail unpredictably. Tyres and brake pads wear down measurably: an advisory tells you roughly how long you have. Corrosion and suspension joints do not behave that way, and an advisory there is less a countdown than a prompt to get a proper look.

Why advisories predict next year's failures

The logic is mechanical rather than statistical. An advisory is issued precisely because a component is close to a threshold. Twelve months of further use moves it closer. Nothing in normal driving reverses tyre wear, pad wear, corrosion or joint play.

That gives you a straightforward way to prepare for a test. Pull up last year's certificate, list the advisories, and treat that list as the agenda. It is far cheaper to replace a pair of tyres at a time of your choosing than to fail a test, lose the use of the car, pay for a retest and then buy the same tyres under time pressure.

The same logic applies in reverse when reading someone else's car. If a vehicle was advised for worn front discs three years running and then suddenly was not, either the discs were replaced or the advisory stopped being recorded — and the first explanation is far more likely if the mileage kept climbing. If an item is advised, then advised again, then appears as a major defect, you are looking at an owner who deferred maintenance until the test forced their hand. That pattern tells you something about how the rest of the car has been treated.

Our guide to red flags in MOT history covers the patterns worth pricing into an offer, and the MOT defect library explains what individual items involve and roughly what they cost to put right.

The advisories you will see most often

These are the categories that dominate ordinary car histories, with what each is telling you.

Tyres

Recorded when tread is above 1.6mm but close to it, or when there is early cracking, uneven wear or minor damage. Uneven wear is the one to take seriously: a tyre worn on one edge usually indicates a tracking or suspension problem, and replacing the tyre without fixing the cause simply buys you the same advisory next year. See tyre tread depth law for the exact measurement rule.

Brakes

Pads or discs wearing thin, discs lightly scored or pitted, and early corrosion on discs that have stood unused. Brake advisories are also sometimes recorded alongside a marginal but passing efficiency reading, which is worth asking the tester about directly, since imbalance between the two sides of an axle is often a sticking calliper rather than worn friction material. Brake testing in the MOT explains how the measurement works.

Suspension and steering

Slight play in ball joints, track rod ends, wheel bearings and suspension bushes. Corroded springs. Shock absorbers showing light misting. These are the advisories most likely to become majors, because the grading depends on a measured amount of movement that only increases.

Corrosion

Split into two very different categories. Surface corrosion on a panel is cosmetic. Corrosion described as being near a prescribed area — within 30cm of a seatbelt anchorage, suspension mounting, steering component or brake mounting — is a warning that the vehicle is approaching a structural failure, and structural corrosion requires proper welded repair to pass.

Leaks and the exhaust

Slight engine oil seepage, a gearbox weeping at a seal, an exhaust starting to blow at a joint. Individually minor, but an oil leak that reaches a tyre or a brake is a different matter, and a leak severe enough to drip is a defect rather than an advisory.

Lights

Clouded or discoloured headlamp lenses, condensation inside a unit, or a lamp aim that is within tolerance but off centre. Cheap to address and, since lighting is the single most common failure area, worth doing.

Advisories, the law and your insurance

There is no legal duty to act on an advisory. No authority checks, no record is kept of whether you did, and nobody can penalise you for the advisory itself.

What can catch you out is the separate legal requirement that a vehicle be roadworthy whenever it is used on a road. A valid MOT certificate is not a defence against that. If a component deteriorates past the legal limit — a tyre drops below 1.6mm, a brake becomes ineffective — you are committing an offence from that moment, whatever the certificate says. Using a vehicle in a dangerous condition carries a fine of up to £2,500, three penalty points and a discretionary disqualification.

Insurance works similarly. You do not declare advisories, and they will not affect a premium. They can matter after an incident, because the MOT record is public, dated and independent. An insurer investigating a collision can see that a tester flagged your front tyres as nearing the limit fourteen months earlier. That is a difficult document to argue with if the tyres are still on the car.

If you genuinely disagree with something recorded at a test — including an advisory you think is wrong or unjustified — you can complain to DVSA about the conduct of the test, and you can appeal a result you believe is incorrect. Advisories are not usually worth formal escalation, but a factual error, such as an advisory recorded against a component that is demonstrably new, is worth raising with the test centre so it can be corrected.

What to do when you get one

1. Read the exact wording. The qualifiers are informative. "Nearing the legal limit" means very close. "Slightly worn" means there is life left.
2. Ask the tester which advisories they would act on. They have just spent an hour under your car and are usually happy to say what they would prioritise. This is the single most valuable free advice available at a test.
3. Separate the safety items from the notes. Tyres, brakes, steering, suspension and structural corrosion belong in a different mental category from a cloudy headlamp lens.
4. Get a quote, but not necessarily from the test centre. An advisory is not urgent by definition, which means you have time to compare prices — a leverage you do not have when a car has failed.
5. Diary it against next year's test. Anything you did not fix will still be there, one year worse.
6. Keep the certificate. When you sell the car, being able to show that advisories were actioned is worth real money.

Reading advisories on a car you are thinking of buying

Every advisory ever recorded against a vehicle in England, Scotland or Wales is public. On a car with a ten-year history, that is ten independent inspections, each documenting what a qualified tester thought was starting to go wrong — evidence no seller controls and no valet conceals.

Read them chronologically rather than as a list. You are looking for four things:

• Repetition. The same advisory three years running means nothing was done.
• Escalation. An advisory that becomes a minor and then a major shows deferred maintenance.
• Clusters. Several suspension advisories in one year suggest the car has had a hard life or a knock.
• Structural language. Anything mentioning corrosion near prescribed areas changes the calculation on an older car entirely.

You can pull the full record for any registration on the MOT history check, and read the current status and due date at the same time. Set that against the common MOT failures and you have a realistic view of what a car will cost to keep on the road — before you commit to it rather than after.