How to Read a UK MOT Advisory in 2026 (After the January Rule Change)

If you've just looked up the MOT history of a car you're thinking of buying and you're staring at a line that says "Drive belt: minor cracks" or "Suspension component: slight play," the answer is almost certainly: don't panic, but don't ignore it either. Most MOT advisories are the tester's polite way of saying "this is fine now but watch it." Some genuinely matter. The job over the next 5 minutes is to tell the difference.

This guide explains, in plain English, what an MOT advisory is, what changed in the January 2026 rule update, and how to read each line on a UK MOT history before you hand over money. It includes a 10-phrase decoder table, the patterns that mean walk away, and a negotiation script for advisories that are real but fixable.

The figures and rule changes here are from the DVSA inspection manual update of 9 January 2026, gov.uk MOT history records, and 2026 fix-cost data from WhoCanFixMyCar and What Car?. Where a number is a CarScreener heuristic rather than a published source, we say so.

What changed in the January 2026 MOT rules

On 9 January 2026, the DVSA updated the MOT inspection manual — the document UK MOT testers actually work from. (gov.uk MOT inspection manual) Three changes matter most for anyone reading an MOT history before buying:

• Tyre tread depth thresholds tightened. The legal minimum is still 1.6mm across the central three-quarters of the tread, but the advisory threshold — the point at which a tester records "tyre worn close to legal limit" — moved from 2.0mm to 2.5mm. More cars will now show a tyre advisory on their first 2026-rules test even though nothing about the tyre has actually changed.
• Brake fluid leak: now a major defect. Previously, a small brake fluid weep at a caliper or union was sometimes recorded as an advisory. From January 2026 it's a major defect — an automatic failure. Any historical advisory mentioning brake fluid weep on a car you're looking at should be treated as urgent: if it hasn't been fixed, the car will fail its next MOT.
• Underbody corrosion: stricter "structural area" definition. The DVSA narrowed what counts as a non-structural rust patch. Sill corrosion that scraped through as an advisory in 2024 will now fail. This matters most for cars 8+ years old in salt-belt counties (Lincolnshire, Norfolk, the Scottish coast).

The takeaway: a car that just passed its first 2026-rules MOT has been tested against a stricter book than the one before it. That's good news for buyers. But it also means an old MOT history reads differently against the new rules — an advisory from 2024 might be a failure today.

The three advisory severity tiers — in plain English

Since 2018, MOT defects have been recorded under three severity tiers (DVSA call them "categories"). They are:

• Minor. Plain English: "Do something about it within a few months." The car still passes. No legal issue. Examples: small bulb out, washer jet weak, very slight play in a steering joint.
• Major. Plain English: "Failure. Fix before you drive." The car has failed the MOT. You can't legally drive it on the road except to a pre-booked repair appointment. Examples: brake imbalance, headlight aim out, brake fluid leak (post-Jan 2026).
• Dangerous. Plain English: "Do not drive away under any circumstances." A failure that also presents an immediate safety risk. The garage will usually refuse to release the keys. Examples: brake failure on one axle, severely worn tyre below 1.6mm, broken coil spring with sharp end exposed.

What people loosely call an "MOT advisory" almost always means a minor item. The car passed. Major and dangerous categories are failures, and a car that has just been MOT'd cannot have an unresolved one — by definition it would still be at the garage. When you read a historical MOT, you'll see "Pass," "Pass with advisories," or "Fail" at the top, and the categories listed underneath.

"Minor cracks on drive belt" and 9 other phrases decoded

The DVSA wording on MOT certificates is consistent across testers, which means the same phrases come up over and over. Here are the ten most common, with plain-English translations, urgency, typical 2026 fix costs, and what to do at the buying stage. Fix costs are independent-garage averages from WhoCanFixMyCar's 2026 quote data and What Car? service-cost surveys.

The pattern: single, cheap, cosmetic advisories on an older car are normal. Anything mentioning the engine internals, head gasket, structural corrosion, or that repeats across multiple tests, is a different conversation.

When an advisory is a walk-away signal

The single advisory line is rarely the problem. The pattern is. Walk away — or at least slow the deal down — if you see any of these:

• The same advisory on 3+ consecutive MOTs. Means the previous owner has been ignoring it and you're inheriting the bill. Most common on suspension and exhaust.
• Multiple advisories on the same system. "Front discs worn," "front pads worn," "front brake pipe corroded" all in one test means the whole front brake system needs work, not a £100 part.
• The advisory contradicts what the seller is telling you. "Just had new tyres" but the most recent MOT (3 weeks ago) flagged a tyre worn close to the legal limit. Either they're lying or someone else's tyre is on the car.
• A mileage discontinuity in the same period as a major service advisory. A drop or flat-line in odometer reading combined with engine or gearbox advisories is the classic clocked-car fingerprint. Around 1 in 7 UK used cars show signs of mileage manipulation, with the Nissan Qashqai (9.7%), Volvo XC60 (8.4%) and Volvo XC90 (7.2%) the most-clocked models in 2025 data, and the Land Rover Defender averaging an eye-watering 59,201-mile rollback when found. (Auto Express citing Regit / cap hpi) Our guide to spotting a clocked car covers the telltales in under 5 minutes.
• A "major" or "dangerous" advisory that's still showing as unresolved on the most recent test. This shouldn't be possible (the car would still be at the garage) — if you see it, the seller has tested elsewhere or paid for a re-test without the actual repair.

When in doubt: ask the seller for the receipt for the work that closed the advisory. A real fix produces a real invoice. No invoice means no fix.

When an advisory is a negotiation lever

This is the section for buyers who already know they want the car and are looking for a calm, defensible reason to ask for £100–£300 off the asking price.

The CarScreener rule of thumb (this is our heuristic — not an industry standard or DVSA recommendation): typical fix cost ÷ 2 at a private sale, ÷ 3 at a dealer. A £180 drive belt advisory becomes a realistic £90 reduction privately, £60 from a dealer. A £250 front-disc-and-pads advisory becomes £125 / £85.

The reasoning: the seller knows the work needs doing, the seller hasn't done it, and you'll be paying for it within 6 months. Splitting the cost is fair. At a dealer the margin is smaller and the stock has been priced more carefully, so the discount you can win is smaller too.

The script line that works:

"I noticed the last MOT flagged [phrase]. What's that going to cost me to put right?"

Three things make this work. First, you've named the advisory — you've shown you've read the history. Second, you've asked them to put a number on it, not you. Third, you've used the word "me," not "you" — you've already taken ownership of the problem, which makes the seller more willing to share the cost.

If they say "nothing, I'll get my mate to do it for free," fine — ask them to do it before the sale and reduce the price by zero. If they say "you'd be looking at £300," now you have their number and can ask for £150 off privately. If they refuse to discuss it at all, that's information about the seller, not the car.

How to actually read the MOT history

Four steps, five minutes, free.

1. Pull the MOT history from gov.uk/check-mot-history. You need the registration. No login. Returns the full test record back to 2005, including every advisory ever recorded.
2. Read the most recent test first. Note the advisory items by system: brakes, tyres, suspension, lights, body. This is the "what does the car need next" picture.
3. Read backwards, year by year. This is where the patterns show. Look for the same advisory repeating, advisories disappearing without an obvious fix (sometimes meaning a different garage decided not to record them), and any test marked "Fail" with the recorded reason.
4. Cross-check the mileage on every test. Numbers should rise smoothly — typically 6,000–10,000 miles per year for an average UK car. Drops, flat years, or one giant jump are red flags. A car with 90,000 miles in 2023 and 75,000 miles in 2024 has been clocked.

If you want this done for you against a specific reg in 30 seconds — including the running-cost estimate, mileage-anomaly check and a translation of every advisory line — the free CarScreener guide does it in one go.

When to ignore an advisory

This is the section for first-time buyers. Not every advisory is a problem. These genuinely don't matter on a sub-£8,000 used car:

• Headlight aim out. £20 fix, often included in a service. Ignore.
• Washer jet weak / not aimed correctly. A new £4 jet from any motor factor. Ignore.
• Number plate fade / not conforming to BS standard. A £25 plate. Ignore.
• Cosmetic corrosion on the boot lid, exhaust heat shield, or non-structural underbody on a 10+ year old car. Normal wear.
• A single advisory cleared at the next test. If 2024 said "rear pad wearing thin" and 2025 said "Pass with no advisories," the work was done. Move on.
• Anything described as "slight" on a single test on a high-mileage car. Slight oil weep, slight play, slight corrosion — these are the words testers use when they want to record "noted, not a problem."

The point of the MOT history is not to find a perfect car. There isn't one. The point is to see whether the car has been maintained honestly and whether anything on the list is going to cost you more than the saving you got at the asking price. If the answer to both is no, it's a buy.

Get a guide to walk you through it

Reading 8 years of MOT history, decoding the wording, cross-checking the mileage, and pricing the fixes is a 30-minute job if you've never done it. Send Claire the registration and she'll read the MOT history for you, flagging which advisories actually matter for this car — using the same logic in the table above, against the actual mileage and ownership pattern of the specific reg.

Send a reg or paste a listing link →

30 seconds. Free to start, no card needed — the reg, the link, or a photo of the certificate.

A car with a clean MOT history isn't always the right car, and a car with a few advisories isn't always the wrong one. The skill is reading what's there, in context, and putting a number on the work the previous owner didn't do. That's the difference between buying a £6,000 car for £6,000 and buying a £6,000 car for £5,800 with eyes open.

For the cost side of the same decision — what the car will run at per month once you own it — see our breakdown of Ford Focus vs Vauxhall Corsa running costs in 2026 or, for a model-specific buyer's guide, the used Ford Fiesta walkthrough.