Nobody writing a used car advert sets out to tell you what's wrong with it. But most sellers aren't outright liars either, so what you tend to get is a sort of careful vagueness: a phrase that's technically true, sat exactly where the awkward detail should have been.
Once you've read a few thousand adverts those phrases start to stand out a mile off. Here are nine of the ones worth slowing down for, and what to ask when you spot one.
None of these mean the car is bad, by the way. They mean there's a question that hasn't been answered yet.
1. "Selling for a friend"
The most useful phrase in the whole list, because it removes accountability before you've even asked anything.
Whoever's stood in front of you can't tell you when the cambelt was done, why it's being sold, or what that noise is, and they've got a ready-made excuse for not knowing. Sometimes it's completely genuine. Often it's a trader avoiding the obligations that come with selling as a business, and occasionally it's somebody selling a car that isn't theirs to sell.
Ask: whose name is on the V5C, and can you speak to them. If the answer is awkward, walk.
2. "Drives spot on"
A blanket claim doing the job of about six specific ones.
An honest advert from someone who knows the car reads differently. It says what's been done and when, what's coming up, and what it needs. "Drives spot on" tells you the seller can get it to the end of the road, and nothing else.
Ask: what's been replaced in the last two years, and what's due next.
3. "Just been serviced"
Fine if there's paperwork. Meaningless if there isn't.
"Serviced" covers everything from a full schedule at a specialist to oil and a filter in a driveway the night before the photos. The word carries no weight on its own, and it's the cheapest possible thing to type.
Ask: who did it, what did they do, and can I see the invoice. An honest seller has it on their phone.
4. "Engine management light is on but it's only a sensor"
The seller has diagnosed the cheapest possible cause of a warning they may not have had read properly.
Sometimes it genuinely is a sensor. But the light is the car telling you something has been logged, and "only a sensor" is a conclusion, not a reading. If it were a £40 sensor, fixing it before advertising would make the car easier to sell, which is worth thinking about.
Ask: what's the actual fault code. If they don't know, that tells you nobody has looked.
5. "Just needs a small welding job for the MOT"
Corrosion is almost never small, and it's the one problem on this list that only gets worse while you think about it.
A welding advisory on a sill or a subframe mount can be an afternoon, or it can be the moment the car stops being worth repairing. You can't tell from the advert and often you can't tell from underneath it either, not without it up on a ramp.
Ask: where exactly, and get it looked at properly before you commit. Then check the MOT history, because corrosion advisories usually have a paper trail going back years.
6. "Genuine mileage"
Unprompted reassurance is its own signal. Nobody selling a straightforward car feels the need to certify the odometer in the advert.
Worth being fair here: plenty of honest sellers write this because they know buyers worry about it. It's not proof of anything either way. It just means the mileage is the thing to go and verify rather than take on trust.
Ask: nothing. Go and read the MOT history yourself, in order, and see whether the readings tell the same story. That's free and it takes two minutes.
7. "Quick sale, moving abroad"
Urgency plus a seller who won't be reachable afterwards.
The combination is what matters. Urgency on its own is often real, people need the money or the space. But urgency paired with a reason you can't follow up on is the setup for every private sale that goes wrong, and it's a very common line in adverts that turn out to be scams outright.
Ask: for the viewing to happen at the address on the V5C. A seller with nothing to hide won't mind. This is also the point where you refuse to pay a deposit to hold it.
8. "New clutch and head gasket fitted"
Big repairs listed as selling points, with no mention of why they were needed.
A fresh clutch is genuinely good news. A fresh head gasket at 80,000 miles raises a question about what caused it, whether the overheating that killed it did anything else on the way past, and whether the head was checked properly or just bolted back on.
Ask: what caused it, who did the work, and can you see the bill. Also worth knowing whether that failure is normal for the model, which is what our common problems pages are for.
9. "Sold as seen, no refunds"
A seller telling you they expect something to go wrong.
Buying privately, your protection is thin anyway. The car has to be as described and roadworthy, but you don't get the quality rights you'd have from a dealer. So "sold as seen" doesn't actually change your legal position much. What it changes is what you know about the seller's expectations, and someone writing it into the advert has thought about this more than they're letting on.
Ask: why they felt the need to write it.
What is the advert not telling you?
Paste the advert text and the registration. We read it against the car's DVSA MOT history and our known-faults database, then tell you what the seller left out.
Check an advert now (free) →What does a good advert look like, then?
Worth saying, because none of this is about assuming the worst.
A good private advert is specific and a bit boring. It says the model and engine properly, the mileage, when the MOT runs out and what came up on it, what's been replaced recently with roughly when, what needs doing, and why it's being sold. It has photographs taken in daylight of the whole car including the bits that look tired, and it invites you to inspect it.
Sellers like that exist in numbers and they're the ones worth driving to see. The specificity is the signal. It's very hard to fake and very easy to check.
How do we use this?
The nine above are the general ones anybody can learn. The more useful version is model-specific, because the phrase that matters depends on what the car is known to do.
Our known-faults database currently holds 616 advert phrases tied to 228 documented faults across 41 manufacturers. These are the things sellers tend to write when a particular known fault is developing on a particular model, which is a completely different problem from spotting a generic scam line. A phrase that means nothing on one car is the tell on another.
That's what the report does. You paste the advert in, and we read the wording against that car's MOT history and the faults recorded for that exact model and engine, then tell you which bits of the advert deserve a question. It's the step almost nobody does, and it's free to try.
So if you've got an advert open, paste it into a free scan along with the registration and see which phrases come back for that specific car. It's the same reading you've just done here, except against the model's actual fault record rather than a general list of nine, and it takes about a minute with no card and no password.
If the car survives that and you're buying privately, the provenance data is an upgrade on the same report with nothing to re-run. It's worth understanding what outstanding finance actually does to a private buyer before you get that far, because that's the one that costs people the most, and what the free checks cover sets out where free stops.
