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Part-worn tyres in the UK — legal, but rarely a bargain
Selling part-worn tyres is legal in the UK, under conditions that investigations suggest are widely ignored. What the law requires of every tyre on the rack, why the per-millimetre maths usually favours new — and the five-minute check if you buy one anyway.
Last reviewed: September 2026 · LCDrive editorial team
Yes, selling part-worn tyres is legal
In Great Britain, the sale of part-worn tyres is governed by the Motor Vehicle Tyres (Safety) Regulations 1994, made under the Consumer Protection Act 1987. The Regulations do not ban the trade. Instead, they make it an offence to supply a part-worn tyre that fails a specific list of conditions — so legality attaches to the individual tyre and the seller who supplies it, not to the concept.
That distinction matters. “Are part-worn tyres legal?” has a precise answer: the trade is legal, and any particular tyre on the rack may not be. Everything below follows from that.
What a legal part-worn must have
Regulation 7 sets the conditions, and every one of them must be met before the tyre is offered for sale. Note the tread figure: 2mm, not 1.6mm. The minimum for selling a part-worn is higher than the minimum for driving on one — the 1.6mm figure is the in-use legal floor, while 2mm across the full breadth of the tread and around the entire circumference is a condition of sale.
| Requirement | What the law says | How to check |
|---|---|---|
| Tread depth | At least 2mm across the full breadth of the tread and around the entire circumference, with the base of every original groove clearly visible | Measure at several points across and around the tyre, not one groove |
| PART-WORN marking | Marked PART-WORN in uppercase letters at least 4mm high, permanent and legible, not hot-branded or cut in, immediately next to every approval (E) mark | Find the E mark on the sidewall — the stamp must sit right beside it |
| No large cuts | No cut deep enough to reach the ply or cord and longer than 25mm or 10% of the section width, whichever is greater | Run a careful hand over the tread and both sidewalls |
| No lumps, bulges or tears | None caused by separation or partial failure of the structure, internal or external | Look and feel along both sidewalls, outside and inside the casing |
| No exposed ply or cord | No cord visible anywhere on the tyre, internally or externally | Inspect the inside of the casing as well as the outside |
| Sound when inflated | Shows none of the external defects above when inflated to the highest pressure it is designed for | Ask the seller whether the tyre was examined inflated |
| Repairs | Any repair carried out properly, to the relevant British Standard | Ask whether the tyre has been repaired, and how |
The marking rule is the quickest test of a seller. A tyre offered as part-worn without the PART-WORN stamp beside its approval mark is being sold illegally — whatever else may be right about it.
What investigations keep finding
The conditions above read like a workable safety net. The problem is compliance. In joint investigations running up to 2018, TyreSafe and Trading Standards visited 152 part-worn retailers over roughly five years and found 139 of them selling illegal and dangerous tyres — only 13 were compliant. A follow-up sweep of 68 traders reportedly found just one operating within the law. The defects were not paperwork technicalities: tyres on sale were found with water inside the casing, with nails and other objects still embedded in the tread — and some buyers were simply supplied the wrong size.
Figures that age should be read as a pattern rather than a live statistic — but the pattern was the same every time inspectors looked: the overwhelming majority of outlets checked were not meeting the legal conditions. In practice, that shifts the burden of checking onto the buyer.
The price-per-millimetre problem
Set legality aside and the economics deserve a harder look than the price tag invites. What you are buying in any tyre is usable tread: the millimetres between the depth on the day you buy and the 1.6mm legal minimum at which the tyre must come off.
Part-worns are commonly sold with around 3mm of tread. From 3mm, the rubber above the legal floor is roughly 1.4mm. A new tyre typically starts at around 8mm, which gives roughly 6.4mm — about four to five times as much usable tread. Now divide price by usable millimetre. At, say, £30, the part-worn works out at roughly £21 per usable millimetre; a new tyre at 6.4mm would have to cost over £135 before its rate caught up. Prices vary and the sums are an illustration, but the shape of the result rarely changes: the cheap tyre is often the expensive one per mile.
A part-worn also reaches that floor sooner — which means replacing sooner, and a shorter distance between purchase and the point where driving on it becomes an offence. The penalty for a tyre below the minimum can reach £2,500 and three penalty points, with each illegal tyre treated separately.
The history you cannot see
A tyre is more than its tread depth. The first life of a part-worn — the kerb it hit at speed, the fortnight it ran under-inflated, the botched puncture repair, the internal separation that has not yet become a visible bulge — leaves damage that may show nothing on the outside. The 1994 Regulations police what an inspector can see and measure on the day of sale; they cannot restore a service history that was never recorded.
Age, at least, can be read. Every tyre carries a DOT code on the sidewall ending in four digits — the week and year of manufacture, so 3623 means week 36 of 2023. Check it before handing over money: a part-worn is second-hand in time as well as tread, and our guide to tyre age and the date code covers what the number means at five and ten years.
When a part-worn can make sense
None of this adds up to “never”. There are honest cases: a nearly new tyre taken off a premium car, with high remaining tread, from a reputable seller who meets the regulation in full; a short-term fix on a car about to be sold; matching a single tyre in an unusual size that is hard to source new. What the honest cases share is that the value per usable millimetre is genuinely good and the condition is verifiable. The problem with the typical part-worn purchase is not the concept — it is buying an unknown tyre at 3mm because the ticket price is low.
If you buy anyway: the five-minute check
Find the PART-WORN stamp
It must sit immediately next to the approval (E) mark on the sidewall, in letters at least 4mm high. If it is missing, the sale is illegal — and a seller who skips the visible requirement has told you something about the invisible ones.
Measure the tread yourself
At several points across the width and around the circumference, not one convenient groove. The sale minimum is 2mm everywhere, and the law judges the shallowest point, not the best.
Inspect both sidewalls — and inside
Look for repairs, bulges, cracking and any exposed cord, on the inner sidewall as well as the outer and around the rim edge. If the seller will not let you examine the inside of the casing, walk away.
Read the date code
The four digits at the end of the DOT code give the week and year of manufacture. Low tread on a young tyre and high tread on an old one are different purchases at the same price.
Ask what was checked, and get a receipt
Ask whether the tyre was examined inflated, whether it has been repaired and to what standard. A compliant seller answers easily; a receipt gives you somewhere to stand if the answers turn out to be wrong.
The alternative is simpler than the checklist. You can browse new tyres by size or find the tyres that fit your car by registration, with fully-fitted prices and mobile fitting at your home, workplace or roadside — a tyre with its whole first life ahead of it, and no history to guess at.