The Advisory You Skimmed Could Be Your Next £800 Bill

Most used-car buyers check two things on the MOT history: did it pass, and when does it expire. Fair enough. But the advisory lines underneath are where the car's real story tends to live. They are free to read on the GOV.UK MOT history service, and they can save you from buying someone else's repair bill.

An MOT pass means the car met the minimum safety and environmental standards on the day of the test. It does not mean the car is fault-free. A tester can pass a car and still note that the brake pipes are corroded, the suspension bushes are worn or the tyres are close to the limit. Those notes are not decoration. They are clues.

Pass, fail, minor, advisory: a quick translation

Since 2018, MOT defects have been split into categories. Dangerous and major defects mean a fail. Minor defects are noted but do not fail the car. Advisories are items to monitor. The wording matters. 'Corroded but not excessively' is doing a lot of work in that sentence. So is 'worn but not excessively'.

A single advisory can be nothing more than a tester being thorough. The same advisory appearing year after year is a pattern. That is when you start asking whether the owner has been maintaining the car or simply driving it until the next test.

Repetition is the signal

Open the MOT history and read it like a timeline. Look at the mileage between tests, the failure items, the advisories and any notes about rectification. If the same corroded brake pipe is mentioned in 2023, 2024 and 2026, nobody has replaced it. If the same tyre advisory appears twice and the car is now on different tyres, fine, ask for the invoice. If an advisory disappears without any evidence of repair, ask why.

A clean current MOT is nice. A clean current MOT with a long history of ignored advisories is not the same thing. The car may have scraped through again, but you will be the one dealing with the next test.

Corrosion: do not skim this one

Corrosion advisories are the ones I would read twice. Wording like 'corrosion to underbody', 'sill corroded' or 'subframe corroded but not excessive' can range from cosmetic surface rust to structural metal that is starting to go. The phrase 'not excessive' is subjective. It is not a guarantee that the metal will still be there next winter.

Pay particular attention to corrosion near suspension mounting points, seat belt mountings, sills, chassis legs and subframes. Those are the areas where rust becomes welding, and welding becomes a painful bill. If the same corrosion advisory appears on both sides of the car over several years, get an independent inspection or walk away. Fresh underseal can hide a lot. A recent MOT pass does not cancel out a history of structural notes.

Brake pipes and hoses

Brake pipe corrosion is a common advisory, and it is safety-critical. The pipes run under the car, often in awkward places, and replacing them can involve more labour than buyers expect. If the MOT history says a brake pipe is corroded, ask whether it has been replaced. If the same note appears again the following year, assume it has not.

A corroded brake pipe can become a fail rather than an advisory. That is exactly the kind of 'tomorrow's repair bill' an MOT history is good at predicting. It is also a useful negotiation point if you are buying from a dealer or a private seller.

Suspension and steering notes

Advisories for worn suspension bushes, misting shock absorbers, corroded coil springs or slight play in steering components are common on older cars. One note on a high-mileage car is not automatically a deal-breaker. A list of them, repeated over several tests, tells you the car has been running on worn components for a while.

Suspension work can add up quickly, especially if it is done in pairs or as a set. Use the advisories to ask what has been replaced and when. If the seller has invoices, great. If not, budget for it. Do not let a shiny set of alloy wheels distract you from a tired front end.

Tyres and brakes

Tyre advisories are easy to dismiss because tyres are consumables. But 'worn close to the legal limit', 'cracked' or 'perished' means you may be buying a car that needs rubber immediately. Check the current tyres against the MOT note. If the MOT was months ago and the tyres are still borderline, price it in.

Brake advisories work the same way. A note about worn discs or pads is not a crisis, but it is a cost. Repeated brake advisories with no evidence of replacement suggest a car that has been maintained to the minimum, not looked after properly.

Emissions notes on diesel and petrol cars

Emissions-related advisories deserve attention, particularly on diesels. Notes about smoke, lambda readings or emissions being close to the limit can point to servicing neglect, EGR problems, injector issues or a DPF that is not happy. None of those are guaranteed, but they are not the cheap end of the repair menu either.

Petrol cars can throw up emissions notes too. A repeated emissions advisory is a prompt to ask about servicing, fuel additives, sensor replacements and any fault codes. If the seller shrugs, factor in a diagnostic check before you commit.

A clean pass is not a clean bill of health

An MOT does not check the clutch, gearbox, air conditioning, infotainment, timing belt, service history or the health of a diesel particulate filter. It does not tell you whether the car has been serviced on time. It does not tell you whether the previous owner ignored a rattle for two years. It is a minimum standard, not a warranty.

A car with no advisories is not automatically better than one with a couple of honest notes. Some testers list more than others. What you want is a car whose MOT history makes sense. Mileage that climbs steadily. Failures that were fixed. Advisories that were addressed, ideally with invoices. A seller who can explain the story.

How to use the MOT trail when negotiating

Read the MOT history before you view the car. Make a short list of repeat advisories. When you inspect the car, check those items first. Ask for invoices for the big ones. Then use the list to have a sensible conversation about price. Do not demand the full cost of every advisory off the asking price. Do ask for a contribution or for the work to be done before collection.

If you are buying privately, the MOT history is one of your few protections. If you are buying from a dealer, it should be part of the paperwork. At Hyde Motors, we would rather show you the boring MOT printout than have you discover it after the sale. A car's history is not a secret. It is part of the car.

An MOT advisory is a free clue about the future. Read it before you make an offer, not after. The money you save might be the £800 you did not spend on someone else's deferred maintenance.