MOT Advisory Red Flags: What They Mean and When to Walk Away
Decode the exact wording DVSA testers use, and learn which advisories are cosmetic and which predict expensive failures.
Every used car listing that's had at least one MOT test carries a history of advisories, and most buyers skim past them without really understanding what they mean. That's a mistake. Learning to read MOT advisory red flags properly is one of the cheapest, fastest ways to avoid buying somebody else's expensive problem.
An advisory isn't a fail. The car passed its test. But DVSA testers flag items that are close to needing attention, and the exact wording they use tells you far more than most buyers realise. "Slight wear" and "excessively worn" are not the same sentence, even though they sound similar to an untrained eye. One is a note for next year. The other is a car you should be negotiating hard on, or walking away from entirely.
This guide breaks down how to read advisory wording properly, which categories of advisory matter most, and when a pattern of advisories should make you reconsider the whole purchase.
Where to check MOT history for free
Every UK car's full MOT history, including exact advisory wording, is available free via the . Always check this before viewing a car, not after.
How to read and act on MOT advisories
Six steps to separate genuine red flags from routine notes
Search the registration on the DVSA's MOT history checker and read every advisory from every test, not just the most recent one. A single advisory about tyre wear is unremarkable. The same advisory appearing on three consecutive tests, worded a little more urgently each time, tells you the seller has been putting off a repair they knew was coming.
Testers use a graded vocabulary, even though it isn't always obvious. "Slight", "minor" and "beginning to" sit at the low end, meaning genuinely early-stage wear worth noting for next year. "Moderate" sits in the middle. "Excessive", "significant" and "considerable" sit at the top; these are the words that should make you stop scrolling and start asking questions, because they mean the tester considered the item close to failing outright.
Not all advisories carry equal financial weight. Corrosion near a structural point, a advisory on a brake pipe, or wear on a suspension component are expensive by nature; parts, labour and sometimes welding. Advisories about a cracked wing mirror casing, a small windscreen chip outside the wiper sweep, or worn floor mats cost very little to sort. Sort the advisory list into safety-critical and cosmetic before you decide how worried to be.
A tyre advisory that appears once and is gone by the next test means the owner fixed it. The same advisory appearing two or three years running, sometimes worded more strongly each time, is the single strongest red flag in an MOT history. It shows a pattern of deferred maintenance, and if they've ignored this one, it's worth asking what else has been quietly let slide.
An advisory for corroded brake pipes on a nine-year-old car in a coastal town is far less alarming than the identical advisory on a four-year-old car that's spent its life in a dry garage. Context changes the story. Ask where the car has lived and how it's been used, then judge the advisory against that background rather than in isolation.
If the MOT history shows a genuine safety-related advisory that's still outstanding, get a quote for the repair before you make an offer. A seller who won't budge on price despite a clear, costed advisory is telling you something. And if a car shows a pattern of repeat, worsening, safety-critical advisories across several years, that's usually a sign to look elsewhere rather than a car worth the hassle of negotiating down.
Common MOT advisory red flags worth knowing
Some advisory categories come up again and again, and it's worth knowing what they typically mean before you're standing on a driveway trying to make a decision under pressure.
Tyre advisories are the most common and usually the cheapest to resolve; a full replacement set rarely runs past a few hundred pounds. Brake advisories deserve more attention, particularly wording like "pad thickness below reference" or "disc worn, pitted or scored", both of which mean parts and labour rather than a quick fix. Suspension advisories, especially anything mentioning a "corroded" or "deteriorated" component, tend to be among the most expensive to put right and are exactly the kind of thing our guide on explores in more depth.
Corrosion advisories deserve special caution. A tester noting "corrosion in close proximity to" a structural point isn't being dramatic; that phrasing exists specifically because DVSA guidance treats structural corrosion as a serious safety consideration, and it tends to worsen quickly once it's visible enough to flag. If you see this wording anywhere in a car's history, get a specialist inspection before you commit, regardless of how good the price looks.
Exhaust and emissions advisories are usually mid-tier in cost, though on newer cars they can point to expensive particulate filter issues rather than a simple pipe replacement. If you're weighing up a diesel specifically, our breakdown of covers exactly this kind of failure pattern in more detail.
Frequently asked questions
No. An advisory is a note about an item the tester expects to need attention soon, but the car has passed its test regardless. Only failure items stop a car passing.
Yes. The DVSA's free MOT history checker shows every advisory from every test a car has had, searchable by registration number, no account required.
Anything worded with "excessive", "significant" or "considerable", plus any advisory involving structural corrosion, brakes, or suspension. These tend to be safety-relevant and expensive to fix.
Not automatically. A long list of minor, resolved advisories is normal for an older car. What matters is whether serious advisories repeat and worsen across multiple tests without being addressed.
Yes, and you should. Get a repair quote for any outstanding safety-related advisory and use it as a starting point for negotiation, or as justification to walk away if the seller won't move.