Driving on an illegal tyre carries a penalty of up to £2,500 and 3 penalty points, per tyre. That means four bad tyres could in theory cost £10,000 and 12 points, an automatic ban. It can also leave your insurance invalid if you're involved in a collision. The penalties are set out in the law on tyre safety (GOV.UK), and they stack up fast because each tyre counts separately.
What makes a tyre illegal?
A tyre doesn't have to be bald to be illegal. Any one of these is enough to land you a fine and points:
- Tread below the legal 1.6mm minimum anywhere in the central three-quarters.
- Cuts longer than 25mm or 10% of the section width, whichever is greater.
- Lumps, bulges or cord visible through the rubber.
- An under- or over-inflated tyre that's clearly unfit for use.
- The wrong size, construction or speed/load rating for the vehicle.
Why the penalties are per tyre
The law treats each defective tyre as a separate offence, which is why the costs multiply so quickly. Two bald tyres is two offences, not one. With all four illegal you're looking at a theoretical £10,000 and 12 points, which is enough to lose your licence outright. Beyond the money, the bigger risk is safety: worn tyres dramatically increase stopping distances in the wet, which is the real reason the limit exists. The penalties are designed to make the legal minimum a floor you don't go near, not a target.
Insurance implications
If you have an accident on tyres that were illegal, your insurer may reduce or refuse a payout, arguing the vehicle wasn't roadworthy at the time. That financial exposure usually dwarfs the cost of new tyres, and it can apply even if the tyres weren't the direct cause of the crash. In practice, a set of illegal tyres turns a claim into an argument you may well lose, on top of the fine and points, so the saving from putting off new tyres is a false economy.
How tyres get checked
Defective tyres are a routine finding at the roadside and in the MOT. Police can stop a vehicle and issue penalties on the spot, and the MOT inspects tread, condition, size and the TPMS every year. The catch is that a tyre can pass a casual glance but be illegal on an inner edge you can't easily see, usually from poor alignment. That's why a proper monthly check, including the inner shoulders, is worth the two minutes it takes.
Stay legal without the hassle
Check your tyres monthly with the quick 20p test and replace anything marginal before it becomes illegal. If you'd rather not drive to a garage on a doubtful tyre, our 24-hour mobile fitters come to you across the UK, day or night. Book here.
