What does MOT advisory mean?
An MOT advisory is a note from the tester about something that isn't bad enough to fail the test today, but is worn, deteriorating or worth watching. Think of it as the tester saying, “this is fine for now, but don't ignore it.”
Advisories don't stop a car passing, and there's no legal requirement to fix them. They're recorded in the DVSA database alongside the result, which means anyone can read them, including the next person who wants to buy the car.
Minor vs major defects: the four categories
Since 20 May 2018, everything a tester finds falls into one of four categories. Two cause a fail, and two are recorded on a pass.
| Category | MOT result | What it means | Example |
|---|---|---|---|
| Dangerous | Fail | A direct, immediate risk to road safety or a serious environmental impact. The car shouldn't be driven until it's repaired. | Brake pipe badly corroded or leaking |
| Major | Fail | Could affect safety, put others at risk or harm the environment. Must be repaired. | Headlamp aim far too high |
| Minor | Pass | No significant effect on safety or the environment, but should be repaired as soon as possible. | Number plate lamp not working |
| Advisory | Pass | Could become more serious in future. Monitor it and repair if needed. | Tyre close to the legal limit |
The difference between minor and major defects matters when you're buying. A car that passed with several minor defects had faults on test day that the owner chose not to fix. That's legal, but it tells you something about how the car has been looked after.
Common MOT advisories and what they mean
Tyres worn close to the legal limit
The legal minimum tread depth for cars is 1.6mm across the central three-quarters of the tyre. An advisory means the tyre is approaching it. Budget for new tyres soon. Also look for “worn on edge”, which can point to a wheel alignment problem.
Brake discs or pads wearing thin
Brakes are consumable parts, so this is routine. Watch for brake advisories that persist for several years, because discs left too long can become pitted, which reduces braking performance.
Corrosion
Wording matters here. “Corrosion to underside, not seriously affecting structure” is common on older cars and often cosmetic. Corrosion on brake pipes, subframes or suspension mounting points is more serious and can be expensive to fix properly.
Suspension bushes and joints
Rubber bushes wear and perish with age. A note about slight play or a worn bush isn't urgent, but it can affect handling and tyre wear and will eventually become a fail.
Oil leaks
“Oil leak, but not excessive” is very common on higher-mileage engines. A minor seep may never need attention. A leak that has turned from advisory into a defect over successive tests shows a problem that's getting worse.
Exhaust leaks and emissions
A minor exhaust leak is often a perished joint or gasket and inexpensive to fix. Left alone, it can get louder, let fumes into the cabin on older cars, and eventually upset the emissions test. On diesels, look out for notes about smoke or the diesel particulate filter, which can be costly if the car has been used mainly for short trips.
MOT advisory check: spotting recurring issues
One advisory in isolation rarely tells you much. The same advisory appearing year after year tells you a lot: it was known, it was cheap to ignore, and nobody fixed it. PlateWise groups repeated advisories by area (tyres, brakes, suspension, lights, corrosion, exhaust and other) so recurring problems stand out immediately.
When you see a recurring issue on a car you're thinking of buying:
- Ask whether the work has been done since the last test, and ask for the invoice.
- Get a rough repair quote and factor it into your offer.
- Have the area inspected at the viewing, or by a mechanic.
A tip for sellers
Advisories on electric and hybrid cars
Electric and hybrid cars skip the exhaust emissions test, but they pick up advisories like any other car, and a couple of patterns are more common:
- Tyre wear. Battery packs make cars heavy, and instant torque is hard on tyres, so “close to the legal limit” can arrive sooner than you'd expect.
- Corroded brake discs. Regenerative braking does much of the slowing down, so the friction brakes are used less and can rust. Testers often note discs that are pitted or scored even on low-mileage cars.
- Suspension wear, again due to the extra weight, especially on cars used on rough roads.
None of these are reasons to avoid an EV, but they're worth knowing when you read its history. If the brakes have been flagged, a good garage can often clean them up with some firm braking and a check of the calipers rather than new parts.
Questions to ask a seller about advisories
When you find advisories on a car you're considering, these questions get useful answers quickly:
- “Has anything on the last MOT been fixed since? Do you have the invoice?”
- “Which garage did the last test, and do they service the car too?”
- “Has the car been driven much since the test?” Compare the answer with our mileage check.
- “Are you aware of anything else the next MOT might pick up?”
An open, specific answer is a good sign. A seller who hasn't looked at their own MOT results, or claims there weren't any when the record says otherwise, is telling you something too. To estimate what an upcoming test will cost you, use the MOT cost calculator.
Do MOT advisories affect insurance?
You don't normally need to tell your insurer about advisories. However, your policy will require the car to be roadworthy. If a component that was flagged as an advisory fails and contributes to an accident, an insurer could argue the car wasn't properly maintained. The safest approach is to treat advisories as a to-do list, not a footnote.
How to prioritise advisory repairs
If your own car has a list of advisories, tackle them in this order:
- Safety items first: tyres, brakes, steering and anything structural.
- Things that cause further damage: worn suspension can ruin tyres, and leaks can damage other parts.
- Things that will become a fail before your next test, so you can spread the cost across the year.
- Cosmetic items last, such as light surface corrosion.
Your next MOT date is a natural deadline. Check it with our MOT due date tool and plan repairs before the one-month window opens.
Reading older MOT results
Tests before May 2018 used different terms. A fail was a “refusal to issue” with reasons listed, and advisories were recorded separately. You may also see PRS, meaning “pass after rectification at station”: a defect was found and fixed while the car was at the test centre. PRS items are a good sign, because the problem was dealt with on the spot.
To see a vehicle's complete record, including older tests, use the MOT history check. For more background, read our guide to MOT advisories explained, and see dangerous, major and minor defects explained for how each category affects the result.