Tyre law

UK tyre law: what the rules ask of your tyres

Tread depth

Cars, light vans and light trailers must have a tread depth of at least 1.6mm across the central three-quarters of the breadth of the tread and around the entire circumference.

Motorcycles, large vehicles and passenger-carrying vehicles must have at least 1mm across three-quarters of the breadth of the tread, in a continuous band around the whole tyre. Mopeds should have visible tread. These rules are set out in annex 6 of the Highway Code.

Condition

A tyre is not legal to use on the road if it has a cut of more than 25mm or 10% of the section width, whichever is greater, deep enough to reach the ply or cord. It is also not legal with any lump, bulge or tear caused by separation or partial failure of its structure, or with any ply or cord exposed.

The full list is in regulation 27 of the Road Vehicles (Construction and Use) Regulations 1986.

Inflation

Tyres must be correctly inflated to the vehicle manufacturer's specification for the load being carried. The Highway Code says to check pressures weekly, before your journey and when the tyres are cold, because warm tyres can give a misleading reading. Your handbook or the plate on the vehicle gives the right figures.

Mixing tyre types

Tyres of different structure, such as radial-ply and cross-ply, must not be mixed on the same axle, and tyres on the same axle must be the same size. The MOT manual treats both as major defects. Run-flat and conventional tyres can be mixed on the same axle, although this is not recommended.

Tyre age

Tyres over 10 years old must not be used on the front axles of goods vehicles over 3.5 tonnes or of passenger vehicles with more than 8 passenger seats. They also must not be used on the rear axles of passenger vehicles with 9 to 16 passenger seats unless those axles have twin wheels. There is no equivalent age limit in law for private cars, but the date code on the sidewall tells you how old any tyre is.

The MOT

At the MOT, tread depth below the legal minimum is a dangerous defect, and so is a lump, bulge or tear. For cars first used on or after 1 January 2012, a tyre pressure monitoring system that is malfunctioning or obviously not working is a major defect. You can read the tester's checks in section 5 of the MOT inspection manual.

Penalties

Using a vehicle with a defective tyre carries 3 penalty points, under endorsement code CU30, and for a car a fine of up to £2,500. The penalty can apply to each tyre that is defective. You can look up the code on GOV.UK's list of endorsement codes.

A note on this guide

This is general information, not legal or professional advice. Rules change, so please check the official sources we link to before you make a decision.