UK Tyre Law — What Every Driver Needs to Know

UK tyre law is clear — but many drivers do not know the rules until they receive a penalty notice or fail an MOT. The law covers tread depth, condition, mixing, load and speed ratings, and pressure monitoring. Getting any of these wrong can mean a fine, points, or an invalid insurance policy.

This guide summarises the law every UK driver needs to know. If you want a free tyre check, our mobile tyre fitting team covers Essex, Hertfordshire and Cambridgeshire — call 01279 881234.

Tread Depth

The legal minimum tread depth in the UK is 1.6mm across the central three-quarters of the tyre, around the entire circumference. The tread must be at least 1.6mm in a continuous band across this area.

Driving on tyres below this limit carries:

• Up to £2,500 fine per tyre
• 3 penalty points per tyre — all four illegal tyres means 12 points and an automatic driving ban under the totting-up rules

There is no exception for "only just below" — 1.5mm is illegal. The safety recommendation is to replace at 3mm, because wet stopping distances rise sharply below that point. See our tread depth guide.

Tyre Condition

A tyre must be free from certain defects to be legal. It is illegal to drive on a tyre with:

• A bulge, lump or tear caused by separation or partial failure of the structure
• A cut in excess of 25mm or 10% of the tyre width, whichever is greater, deep enough to reach the cords
• Exposed ply or cord

A bulge indicates internal belt damage and can fail without warning at speed. Any of these defects will fail an MOT and can be prosecuted. See our pothole damage guide and slow puncture guide.

Mixing Tyre Types

The law on mixing tyres is specific:

• You must not mix radial and cross-ply tyres on the same axle
• Tyres on the same axle must be the same size and type
• It is strongly recommended not to mix tyres of different tread patterns or brands across an axle, though this is not strictly illegal

Run-flat and standard tyres should never be mixed on the same car — see our run-flat guide.

Speed and Load Ratings

Your replacement tyres must meet or exceed the original speed and load ratings specified for the vehicle by the manufacturer. These are shown on the tyre sidewall and in the vehicle handbook. See our tyre sidewall guide to read them.

• Fitting a lower speed rating is not legal and can invalidate insurance
• Fitting a lower load index is not legal and can be unsafe, especially on loaded vehicles and EVs (see our EV tyre guide)

A higher rating than standard is legal and is often a sensible upgrade for longevity.

Tyre Pressure

There is no specific law on tyre pressure, but driving on significantly under- or over-inflated tyres can be prosecuted under the broader offence of using a vehicle in a dangerous condition. Under-inflation also causes overheating and blowouts. Check pressures monthly — see our tyre pressure guide.

Tyre Age

There is no legal age limit for car tyres in the UK, but driving on dangerously degraded old tyres could be prosecuted under "using a vehicle in a dangerous condition". Most manufacturers recommend replacing tyres over 10 years old. See our tyre age guide.

TPMS

All new cars sold in the EU and UK since November 2014 must be fitted with a Tyre Pressure Monitoring System. A faulty or disabled TPMS will cause an MOT failure. Removing or disabling it is not recommended and can affect insurance. See our TPMS guide and our TPMS sensor replacement service.

Spare Tyres

There is no legal requirement to carry a spare tyre, and many new cars no longer come with one. However, if you do carry a spare and it is fitted in an emergency, it must itself meet all the legal requirements — tread, condition, and ratings. A "space-saver" spare is usually limited to 50mph and must be replaced with a full tyre as soon as possible.

Penalties and Enforcement

Tyre offences are enforced by the police and can also be picked up at an MOT. The penalties are among the most serious for a vehicle defect offence:

• Up to £2,500 and 3 points per illegal tyre
• An MOT failure for any illegal tyre
• Potential prosecution for dangerous driving if a defective tyre contributes to an accident
• Invalid insurance if a tyre's load or speed rating is below specification

Free Tyre Check

Most drivers never check their tyres until something goes wrong. A two-minute check of tread, pressure and condition keeps you legal and safe. If you want a professional to check all four tyres, call us on 01279 881234 — we come to you across Essex, Hertfordshire and Cambridgeshire and can supply and fit replacements from stock. See our all locations page for coverage.