Part-worn tyre checker

What UK law requires for part-worn tyres

The Motor Vehicle Tyres (Safety) Regulations 1994 make it an offence to sell a part-worn tyre unless it meets all of these:

• Tread of at least 2 mm across the full breadth of the tread and all the way round. This is stricter than the 1.6 mm driving limit.
• "PART-WORN" marked on the sidewall in capital letters at least 4 mm high, permanent and legible, next to the approval mark. It must not be hot-branded or cut into the rubber.
• Original markings: the E-mark (for example E11) and load and speed index (for example 91V) moulded on at manufacture. Retreads have their own marking rules.
• No cut over 25 mm or 10% of the section width (whichever is greater) that reaches the ply or cord.
• No lumps, bulges or tears caused by the structure separating or failing, inside or out.
• No exposed ply or cord, inside or out.
• No unrepaired penetration damage. Repairs must meet the British Standard (BS AU 159).

The tyre must meet these whether deflated or inflated to its highest operating pressure. Sellers must not keep unsafe tyres for sale. These rules are enforced by local Trading Standards.

The 1.6 mm legal tread limit

Once a tyre is on a car, light van (up to 3.5 tonnes) or light trailer, the legal minimum is 1.6 mm across the central three-quarters of the tread, in a continuous band all the way round. Other vehicles, such as motorcycles and lorries, have different limits.

Driving on a tyre below the limit, or one with dangerous damage, can mean a fine of up to £2,500 and 3 penalty points per tyre. Four illegal tyres could mean 12 points and a ban.

Most tyre experts recommend replacing at 3 mm, because grip in the wet drops noticeably below that.

How to check tread depth

• Tread wear indicators: small raised bars in the main grooves. When the tread is level with them, the tyre is at 1.6 mm.
• The 20p test: put a 20p coin in the main grooves. If you can see the coin's outer band, the tread may be close to or below the limit. Check with a gauge.
• A tread depth gauge: cheap, quick and the most accurate way. Check in at least three places across the tyre and at several points round it.

Tips if you buy part-worn

• Check the date code with the tyre age checker. Part-worns are often several years old already.
• Ask to see the tyre inflated and look at the inside before it is fitted.
• Expect less life: a 4 mm tyre has only about 2.5 mm of usable tread before the 1.6 mm limit.
• If a seller is offering tyres that break these rules, report them to Trading Standards through the Citizens Advice consumer helpline.

Sources

• The Motor Vehicle Tyres (Safety) Regulations 1994 (legislation.gov.uk)
• Business Companion (Trading Standards): Part-worn tyres
• The Road Vehicles (Construction and Use) Regulations 1986, regulation 27

Rules and figures last checked: November 2026. Sources are listed above so you can check them yourself.