An advisory on your MOT certificate is not a fail. It’s not a legal obligation. It’s not a booking confirmation for the garage’s workshop. It is an observation by the tester about something they noticed during the inspection that doesn’t currently meet the threshold for any of the defect categories — Dangerous, Major, or Minor — but that they think is worth flagging.
That’s the definition. The confusion arises because advisories span an enormous range of actual significance, from “your nearside front tyre is approaching the legal limit” — which genuinely needs attention before your next long journey — to “minor surface corrosion to rear lower body panel” — which describes approximately forty percent of UK cars over eight years old and requires no action whatsoever.
Knowing the difference saves you money. Ignoring all advisories is reckless. Treating every advisory as a workshop instruction is expensive.
What an advisory actually is
An advisory is raised when a tester observes an item that is currently within the pass threshold but is showing a condition that may deteriorate. The inspection manual doesn’t explicitly list every item that warrants an advisory — it’s a discretionary call by the tester, made after they’ve confirmed the item isn’t yet at fail level.
The key word is “yet.” An advisory is almost always forward-looking. Brake pads at 2.5mm are above the 1.5mm minimum, so the car passes. But 2.5mm is close enough that they’ll likely be at or below minimum before the next test, so the tester notes it as an advisory. That advisory is useful information. The pad manufacturer’s wear rating, the distance you cover per year, and your braking style all affect how much time you have — but in most cases “two or three months” is the right frame, not “sort it when the next MOT comes around.”
By contrast, an advisory noting minor oil seeping from a rocker cover seal is often recorded because the tester saw a slight residue. It happens. Many engines have a weep that never progresses. If the advisory reappears at successive tests and the weep is getting worse, that’s a different conversation. If it’s been there for three years and the oil level is stable, it’s background information.
The advisories that need a prompt response
Tyre tread approaching the legal limit
The legal minimum tread depth in the UK is 1.6mm across the central three-quarters of the tyre, all the way around. Tyres tend to get advisories when the tester reads 2mm or below on the shallowest part of the tread. The distance between 2mm and 1.6mm at normal wear rates can be a matter of weeks.
Below 1.6mm, the tyre is illegal and the car would fail its next MOT. More practically, wet-weather stopping distances increase sharply below the legal limit. A tyre with 1.6mm of tread takes approximately double the stopping distance of a new tyre in wet conditions.
If an advisory notes “tyre tread approaching legal minimum” on any corner, replace it before your next long motorway run. The cost of a tyre is not comparable to the cost of what happens when one doesn’t stop in time.
Brake pads thin or approaching service limit
Most advisory wording on pads will note the approximate measurement the tester observed. A figure of 2mm or below should be treated as urgent. The DVSA minimum is 1.5mm, but brake performance begins to degrade before that — pad material at 2mm can run out faster than expected if you cover significant urban mileage.
A complication is that pads on the same axle should be replaced as a pair, and disc condition matters: a disc that’s been worn by thin pads may have developed grooves or scoring that warrants replacement alongside the pads. The advisory won’t tell you that — the tester isn’t doing a full component assessment, just noting what they observed.
Suspension component showing play or deterioration
Suspension advisories range widely. A worn anti-roll bar drop link showing slight movement is an advisory that can wait a month or two. A lower ball joint showing measurable play is an advisory that shouldn’t wait at all — ball joints are load-bearing, and when they fail they fail suddenly.
The advisory wording should give you the component and the approximate severity. “Slight play” in a track rod end that passed at 4mm of movement is different from “significant play” that just missed the fail threshold. If the component is load-bearing — ball joints, wheel bearings, steering joints — act within a week. If it’s a sway bar link or a minor bush, you have more latitude.
Steering or wheel alignment issues noted
Advisories mentioning uneven tyre wear patterns are almost always pointing to an alignment problem. Misalignment doesn’t fix itself and it accelerates tyre wear on the affected corners. A wheel alignment check costs £40–£60 at most centres. A set of front tyres worn prematurely by uncorrected alignment costs considerably more.
The advisories you can file
Surface corrosion on body panels
The MOT inspection manual is explicit: cosmetic corrosion that hasn’t compromised structural integrity or the attachment of safety components is not a fail item. An advisory noting surface rust on a sill or wheel arch is the tester recording a condition, not identifying a safety risk. Unless the corrosion is progressing rapidly or starting to affect structural sections, the appropriate response is monitoring — an annual eye-over the affected area, a coat of rust treatment if you want to slow it — not an urgent workshop booking.
Minor oil weeps that aren’t progressing
As noted above: a static oil weep that has been advised for two consecutive years and hasn’t led to measurable oil loss between services is background noise. Keep an eye on the oil level. If it’s stable, the advisory is being recorded by the tester because they saw residue, not because something is acutely wrong.
Brake pipe surface corrosion — the nuance
This one deserves its own paragraph because it’s the most commonly misread advisory in the category. Surface corrosion on brake pipes is extremely common on UK cars over five years old — the salt from winter roads attacks the outer surface of the steel pipes. An advisory noting “surface corrosion to brake pipes” means the corrosion has been observed but hasn’t yet pitted through to the bore.
A corroded brake pipe that hasn’t failed is not the same as a functioning brake pipe. But the jump to “replace all brake pipes immediately” isn’t justified by an advisory — it’s justified by an inspection that finds pitting deep enough to compromise the pipe’s pressure integrity. That’s a fail, not an advisory.
If the wording says “surface corrosion” and the tester still passed it, take a look at the pipes when the car is next serviced. If they’re actively scaling or the corrosion is advancing, get a quote. If they look stable, check again next year.
Wiper blades leaving uncleared sections
If the wiper blades are clearing the primary vision zone without streaking but leaving a small arc unswept at the periphery, the advisory is noting a condition that doesn’t currently impair driving vision. The blades will need replacing at some point — they’re consumables. But an advisory on wiper blades is not a safety concern that demands action this week.
Advisories as upselling tools
Some stations use the advisory section heavily. A VT20 with ten advisories on a car that’s in perfectly reasonable condition should prompt you to read each one carefully against the actual description, not accept the list as a pre-approved repair schedule.
The pattern to watch for: an advisory that describes an item requiring workshop labour rather than a genuinely observed deteriorating condition. “Recommend power steering fluid service” is not a standard advisory. “Recommend brake fluid change” is sometimes used as an advisory even when the item isn’t an MOT testable criterion. These aren’t advisories in the DVSA sense — they’re service recommendations dressed in advisory language.
Cross-reference any unexpected advisory against the defect categories guide to check whether the item is actually a testable criterion. If it isn’t, the advisory doesn’t belong there. You can also check the DVSA’s MOT inspection manual at gov.uk/guidance/mot-inspection-manual-for-private-passenger-and-light-commercial-vehicles to confirm.
What to do with advisories on a car you’re buying
The gov.uk/check-mot-history service shows every advisory ever recorded against a vehicle, going back years. A car with the same tyre-wear advisory at four consecutive tests and no record of alignment work in the service history has almost certainly been run on misaligned wheels for four years. The tyres that are on it now may be at the cusp. That’s a negotiating point, or a reason to walk away.
For a full guide on reading the history record and spotting patterns, see how to read MOT history on gov.uk. For the cost of acting on specific advisory items — replacement tyres, brake pads, alignment — the MOT cost estimator gives a realistic range before you’ve had a quote.