MOT Advisory Meaning: What It Is, When to Worry, and Common Codes Explained
An MOT advisory is a warning from the tester that something on your car is wearing or worth monitoring, but it is not serious enough to fail the test. Your car still passes and stays legal to drive, tax, and insure. Advisories are not legally binding, but many progress to failures within 12 months, so treat them as a prioritised maintenance to-do list.
MOT Advisory Meaning: What It Is, When to Worry, and Common Codes Explained
You've just picked up your car from the garage. It passed the MOT — brilliant. But then you spot a list of "advisories" on the certificate and suddenly you're wondering: is my car actually safe? Do I need to spend hundreds of pounds fixing these things?
MOT advisories confuse millions of motorists every year, and garages aren't always great at explaining them. This guide covers everything — what an advisory is, how it differs from a failure, and what the most common advisory codes mean in plain English.
What Is an MOT Advisory?
An MOT advisory is a note from the tester flagging something on your vehicle that isn't bad enough to cause a failure right now, but could become a problem in the future. Think of it as an early warning.
Your car still passes the MOT with advisories on the certificate. They're not legally binding — you won't be fined for driving with them. But they are worth paying attention to, because many advisories turn into failures if left unchecked for another 12 months.
An advisory is not a failure. Your car is roadworthy today. The tester is simply telling you, "Keep an eye on this."
The 2018 MOT Defect Categories Explained
In May 2018, the DVSA overhauled the MOT testing system. Before that, items were either a pass, an advisory, or a failure. The new system introduced four defect categories:
| Category | What It Means | Does Your Car Pass? |
|---|---|---|
| Dangerous | A direct and immediate risk to road safety or the environment. The vehicle must not be driven until repaired. | No — immediate failure |
| Major | A significant defect that affects safety, the environment, or the vehicle's roadworthiness. Must be repaired before the vehicle can pass. | No — failure |
| Minor | A defect that has no significant effect on safety or the environment, but should be repaired as soon as reasonably possible. | Yes — pass with minor defect noted |
| Advisory | Something the tester wants to bring to your attention. It could deteriorate further, or it's worth monitoring. | Yes — pass with advisory noted |
Most people miss the distinction between minor defects and advisories. A minor defect technically falls short of the standard but isn't serious enough to fail. An advisory is even less severe — more of a heads-up. Both allow your car to pass, but a minor defect is recorded as an actual defect, while an advisory is a monitoring note.
In practice, garages and motorists tend to lump them together. The takeaway is the same: your car passed, but there are things worth watching.
MOT Advisory vs Failure: What's the Actual Difference?
Let's make this as clear as possible.
Failure (dangerous or major defect): You cannot legally drive the vehicle until the issue is repaired and retested. A dangerous defect means the car shouldn't be driven at all — not even to another garage.
Advisory or minor defect: Your car has passed. You can drive it, tax it, and insure it as normal. There is no legal requirement to fix advisories.
However — just because it's not legally required doesn't mean it's smart to ignore. An advisory for "tyre worn close to the legal limit" today is very likely a failure in six months. Treat advisories as your maintenance to-do list, prioritised by urgency.
Do I Have to Fix MOT Advisories?
Legally, no. Your car has passed, and you're free to drive it.
But there are good reasons to address them:
- Safety. Worn brake pads might be above the minimum today, but could be metal-on-metal in a few thousand miles.
- Cost. Catching problems early almost always costs less. A worn CV boot is a cheap fix now; a destroyed CV joint is a much bigger bill later.
- Your next MOT. Many advisories progress to failures within 12 months.
- Resale value. Buyers and dealers check MOT history online. Recurring advisories don't inspire confidence.
Prioritise anything related to brakes, tyres, and suspension. Cosmetic or minor corrosion items can usually wait.
Will Advisories Become Failures Next Year?
Not necessarily — but often, yes. A tyre that's "worn close to the legal limit" in March will almost certainly be below the limit by the following March. But "slight corrosion on a brake disc" might stay the same for years.
It depends on the part, your mileage, your driving style, and conditions. A car on a wet driveway in Manchester corrodes faster than one garaged in Surrey.
Want a clear picture of which advisories to worry about? Try our free AI MOT health check. Pop in your reg and we'll explain every advisory in plain English — including how urgent each one is.
The Most Common MOT Advisories Explained
Here are the advisories that appear most often on UK MOT certificates, with plain-English explanations, urgency ratings, and estimated repair costs.
1. Tyre Worn Close to the Legal Limit
What it means: Your tyre tread depth is approaching the legal minimum of 1.6mm. It hasn't failed yet, but it's on its way.
How urgent: High. Worn tyres significantly reduce grip in wet conditions. You also risk a fine of up to £2,500 and three penalty points — per tyre.
Estimated cost: £50–£150 per tyre depending on size and brand.
2. Brake Disc Worn but Above Minimum Thickness
What it means: The disc your brake pads clamp onto has worn down through normal use. Still thick enough to be safe, but getting thinner.
How urgent: Medium. Discs wear slowly, so this could remain an advisory for a while. But if the pads are also worn, things speed up.
Estimated cost: £80–£180 per axle (usually replaced in pairs, front or rear).
3. Brake Pad Worn but Above Minimum Thickness
What it means: The friction material on your brake pads is getting thin. Still enough to stop you safely, but heading the wrong way.
How urgent: Medium to high. Pads wear faster than discs. With lots of town driving, these can go from advisory to failure within months.
Estimated cost: £40–£100 per axle for pads only. Often done at the same time as discs.
4. Slight Play in a Suspension Component
What it means: A ball joint, track rod end, drop link, or bush has a small amount of excess movement. Not enough to fail, but the tester noticed it.
How urgent: Medium. Worn suspension components affect handling and tyre wear. They worsen gradually, but don't leave them for years.
Estimated cost: £60–£200 per component. Bushes are cheaper; ball joints and track rod ends cost more.
5. Oil Leak — Not Excessive
What it means: Oil is seeping from the engine or gearbox, but it's not dripping onto the road or creating a hazard. Most older cars have at least a minor oil leak.
How urgent: Low to medium. If your oil level stays stable between services, it's more nuisance than danger. If you're topping up frequently, get it looked at.
Estimated cost: From £30 for a new sump plug washer to £300+ for a gasket replacement. Many motorists simply live with minor leaks and monitor them.
6. Corrosion — Not Structural
What it means: Surface rust on a body panel, subframe, or underbody component. It hasn't eaten through anything structural — the metal is still solid.
How urgent: Low. It only becomes a problem if left to spread to structural areas like chassis rails, sills, or suspension mounts.
Estimated cost: £0 if you treat it yourself with a wire brush and rust converter. Professional repair: £50–£300.
7. Exhaust Has Minor Corrosion
What it means: Rust on your exhaust pipe, silencer box, or catalytic converter heat shield. It hasn't holed through or started blowing.
How urgent: Low. Exhausts rust — it's what they do. This only matters when corrosion creates a hole and the exhaust starts blowing (you'll hear it).
Estimated cost: £20–£50 for exhaust repair paste. £100–£300 for a replacement section.
8. CV Boot Slightly Deteriorated or Damaged
What it means: The rubber boot covering your CV (constant velocity) joint is showing signs of cracking or minor splits. It hasn't fully split open yet.
How urgent: Medium. Watch this one. Once a CV boot splits completely, dirt gets into the joint, and a cheap boot replacement turns into a £200+ joint replacement.
Estimated cost: £60–£120 for a CV boot replacement. Much cheaper than waiting until the joint itself is damaged.
9. Headlamp Aim Borderline
What it means: Your headlights are aimed slightly off — either too high (dazzling others) or too low (not lighting enough road). Still within tolerance, but only just.
How urgent: Low to medium. Misaimed headlamps affect night visibility and can blind other drivers. Fortunately, this is one of the cheapest fixes going.
Estimated cost: £10–£30 at most garages. Some will do it free if you're having other work done. You can also adjust them yourself with a screwdriver and a flat wall.
10. Wiper Blade Slightly Worn
What it means: Your wipers aren't clearing the screen perfectly — smearing, streaking, or missing patches. Not bad enough to fail, but getting there.
How urgent: Low. Worn wipers are a safety issue in heavy rain though, and new blades make a real difference. Probably the easiest fix on this list.
Estimated cost: £8–£25 for a pair. You can fit them yourself in two minutes.
How to Check Your Car's MOT Advisories
Every MOT result since 2005 is stored on the DVSA database and linked to your registration number. You can check your full history using the government's free MOT history checker.
But if you want those results explained in language that makes sense, use our AI-powered MOT checker. It pulls your data, highlights what matters, and tells you what to prioritise — no jargon, no guesswork.
Quick Tips for Dealing With MOT Advisories
- Don't panic. Your car passed. Advisories are information, not emergencies.
- Prioritise safety items. Brakes, tyres, and suspension first. Everything else can wait.
- Get quotes early. Shop around now rather than scrambling the week before your next MOT.
- Keep records. Receipts for fixed advisories show future testers and buyers you've been proactive.
- Check your MOT history. If the same advisory appears three years running and is worsening, act on it.
For a deeper look at the items most likely to cause an outright failure, have a read of our guide to the top 10 most common MOT failures.
Get Your Advisories Explained in Seconds
Our free AI health check tool reads your latest MOT results and translates every advisory into plain English — what's urgent, what can wait, and what it's likely to cost.
Check your car's MOT health now — just enter your reg and let the AI do the rest.
Good question
Frequently asked questions
What does an MOT advisory mean?
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An MOT advisory is a note from the tester flagging something that is not bad enough to cause a failure right now but could become a problem in future. Think of it as an early warning. Your car still passes the MOT with advisories on the certificate, and they are not legally binding, so you will not be fined for driving with them. They are worth attention though, as many advisories turn into failures within the next 12 months.
What is the difference between an MOT advisory and a failure?
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A failure means a dangerous or major defect, and you cannot legally drive the vehicle until it is repaired and retested. A dangerous defect means the car should not be driven at all. An advisory or minor defect means your car has passed, so you can drive, tax, and insure it as normal with no legal requirement to fix it. The difference is simple: a failure stops you driving, an advisory does not.
Do I have to fix MOT advisories?
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Legally, no. Your car has passed and you are free to drive it. But there are good reasons to address them. Worn brake pads above the minimum today could be metal-on-metal in a few thousand miles. Catching problems early almost always costs less, and many advisories progress to failures within 12 months. Buyers and dealers also check MOT history online. Prioritise anything related to brakes, tyres, and suspension first.
Will MOT advisories become failures next year?
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Often, but not always. A tyre worn close to the legal limit of 1.6mm in March will very likely be below the limit by the following March. But slight corrosion on a brake disc might stay the same for years. It depends on the part, your mileage, your driving style, and the conditions, a car kept on a wet driveway corrodes faster than one garaged in a dry area. Check your MOT history to spot recurring advisories that are worsening.
What are the most common MOT advisories?
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Common advisories include a tyre worn close to the legal limit, brake discs or pads worn but above minimum thickness, slight play in a suspension component such as a ball joint or track rod end, a minor oil leak that is not excessive, non-structural surface corrosion, minor exhaust corrosion, a slightly deteriorated CV boot, borderline headlamp aim, and worn wiper blades. Prioritise brakes, tyres, and suspension; cosmetic or minor corrosion items can usually wait.
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