MOT advisories: what they mean and whether to fix them
An advisory isn't a fail. It's the tester telling you what's likely to fail next time.
Checked against the MOT inspection manual and GOV.UK guidance · Updated November 2026
Advisories appear at the bottom of the MOT certificate and on the online MOT history. They record items that currently meet the standard but are wearing, deteriorating or close to a limit. There's no legal requirement to act on them – but they're a written record that you were warned.
The most common advisories
| Advisory wording (typical) | What it means | Becomes a fail when… |
|---|---|---|
| Tyre worn close to legal limit | Tread around 2mm | Below 1.6mm across the central ¾ |
| Brake pad(s) wearing thin | Pads approaching minimum | Under 1.5mm, or wear indicator on |
| Brake disc worn, pitted or scored | Lipped or corroded discs | Significantly weakened or excessively worn |
| Corrosion to underside / sill, not excessive | Surface rust | Excessive corrosion within 30cm of a prescribed area |
| Suspension arm pin or bush worn | Slight movement | Excessive movement |
| Oil leak | Slight seepage | Leaking excessively, or a fire/environmental risk |
| Exhaust has minor leak / corroded | Early deterioration | Major leak or insecure |
| Windscreen chip outside zone A | Small damage | Spreads into zone A or exceeds 40mm |
Should you fix them?
Use this rule of thumb:
- Tyres and brakes: yes, soon. These deteriorate quickly and the consequences are serious. An advisory on tyre tread in November can be illegal by February.
- Corrosion: treat surface rust now (wire brush, rust converter, underseal). It's the difference between a £30 job this year and a £600 welding bill next year.
- Bushes, ball joints, slight leaks: budget for them before the next MOT; get them done alongside other work to save labour.
Do advisories affect insurance?
An advisory itself doesn't invalidate insurance. But if you have an accident and the cause relates to an item flagged on an advisory you ignored – worn tyres or brakes, for example – the insurer may argue you failed to keep the car roadworthy.
Advisories and selling a car
Buyers increasingly read the MOT history before viewing. A long list of corrosion and suspension advisories will knock money off, or put people off altogether. It's also the best warning you'll get that the next MOT could be expensive – which is often the moment to decide whether to keep, sell or scrap an older car.