UK Tyre Law: What Every Driver Must Know
Driving on illegal or defective tyres puts lives at risk and carries severe legal penalties. Here is what UK law mandates for cars, light commercial vans, and trailers.
In the UK, tyre regulations are strictly enforced under the Road Vehicles (Construction and Use) Regulations 1986. Operating a vehicle with tyres below legal limits not only compromises vehicle control and braking distance, but also exposes drivers to substantial fines, penalty points, and invalidated motor insurance.
Whether you manage a commercial fleet or commute daily around North London, understanding the 1.6mm tread standard, sidewall damage limits, and tyre load ratings keeps your vehicle roadworthy and compliant.
The 1.6mm Minimum Tread Depth Rule
For passenger cars, light utility vans and light trailers, the law specifies a minimum tyre tread depth of 1.6 millimetres across the central three-quarters of the tyre's breadth, and around the entire circumference.
While 1.6mm is the legal threshold, motoring safety bodies and tyre manufacturers strongly recommend replacing tyres once they reach 3mm, as wet-weather braking distance increases drastically below this point.
Legal vs Illegal Tyre Conditions
- Tread depth ≥ 1.6mm across central 75%
- Correct load and speed index for vehicle
- No visible cords, ply or structural bulges
- Matching radial tyres on the same axle
- Tread below 1.6mm in any continuous band
- Sidewall lumps, bulges, or tears deeper than 25mm
- Exposed internal plies or steel cords
- Temporary spare used at excessive speeds
How to check your tyre tread at home
The 20p Coin Test
Insert a 20p coin into the main grooves of the tyre. If the outer band of the coin is hidden, your tread is above the 1.6mm legal limit. If the outer band is visible, your tyres may be illegal.
Inspect Tread Wear Indicators (TWIs)
Modern tyres feature raised rubber bars at 1.6mm within the tyre grooves. When the tread wears flush with these bars, immediate replacement is required.
Inspect the Inner & Outer Sidewalls
Check both the exterior and interior sidewalls for bulges, cracks, or embedded road debris such as screws or glass.
Frequently asked
What is the penalty for driving on illegal tyres in the UK?
Police can issue a fine of up to £2,500 and 3 penalty points per illegal tyre. If all four tyres are defective, you face up to £10,000 in fines and 12 penalty points (an automatic driving ban).
Does a bald tyre invalidate car insurance?
Yes. If an accident occurs and your vehicle has illegal or bald tyres, insurance companies can refuse to pay out claims for vehicle damage.
Are the tread depth rules the same for commercial vans?
Yes, goods vehicles not exceeding 3,500kg (3.5t GVW) are held to the same 1.6mm minimum tread requirement as passenger cars.
Need mobile tyre help now?
Call or WhatsApp with your location, registration and tyre size — we'll confirm availability and the right next step.
Stranded?
We're already on our way.
Puncture at 3am. Blowout on the M25. Locked wheel nut. Whatever it is, call and tell us where you are and what has happened.
Share your location, registration and tyre size so we can confirm the suitable help.
Message on WhatsApp