UK Tyre Tread Depth Legal Requirements — What Every Driver Must Know

Under UK law, car tyres must have a minimum tread depth of 1.6mm across the central three-quarters of the tyre, around its entire circumference. This applies to cars, light vans, and trailers. Being caught with a tyre below this limit carries a fixed penalty of £2,500 and three penalty points — per tyre. Four defective tyres could theoretically result in a £10,000 fine and 12 penalty points, meaning an instant driving ban.

While 1.6mm is the legal minimum, many road safety experts recommend replacing tyres well before this point. At 3mm of tread depth, the stopping distance of a car in wet conditions begins to increase significantly. The difference between 3mm and 1.6mm of tread in a wet braking scenario can add several additional metres to your stopping distance — enough to cause a serious collision.

Checking tread depth is easy and takes less than a minute. A 20p coin is a practical gauge — insert it into the tread groove and if the outer band of the coin is visible, your tread is likely below 3mm and you should consider replacement soon. Dedicated tread depth gauges are inexpensive and give a precise reading. If you are unsure about any of your tyres, Castle Mobile Tyres can assess them and fit replacements on the spot.