Are part-worn tyres safe? What to check before you buy
Short answer: a part-worn tyre can be safe if it meets UK law, has been properly inspected and isn't too old. The problem is that you often can't tell from the outside, and not every seller follows the rules. Here's how to tell the difference.
Going through a used tyre now? Use the part-worn tyre checker as you look at it.
Are part-worn tyres legal?
Yes. Part-worn (second-hand) tyres are legal to sell and fit in the UK. They're popular because they cost less than new. Millions are sold every year, and in a 2026 survey by The Motor Ombudsman, almost a third of drivers said they would consider buying them.
But the same survey found that over 40% of potential buyers didn't know part-worns must be marked "PART-WORN" on the sidewall. That's the first thing to check, and many buyers miss it.
What the law requires
Under the Motor Vehicle Tyres (Safety) Regulations 1994, it's an offence to sell a part-worn tyre unless it has:
- At least 2 mm of tread across the full width and all the way round
- "PART-WORN" marked permanently on the sidewall in capitals at least 4 mm high, next to the approval mark. It must not be hot-branded or cut in
- The original markings: the E-mark and the load and speed index moulded on at manufacture
- No cuts over 25 mm (or 10% of the tyre's width, whichever is bigger) that reach the cords
- No lumps, bulges or tears, inside or out
- No exposed ply or cord, inside or out
- No unrepaired punctures, and any repair done to the British Standard
The tyre must pass these checks both deflated and inflated to its maximum pressure. Some damage only shows when the tyre is inflated.
The hidden risks
A tyre can meet every rule above and still have problems you can't see:
- Unknown history. It may have been driven flat or under-inflated, or hit a kerb or pothole hard. Running flat can wreck the inner sidewall while the outside looks fine.
- Internal damage. Separations and broken cords inside the tyre may only show up on the rim, under pressure, or not until the tyre fails.
- Age. Many part-worns are imported and already several years old. Check the date code: a tyre with 5 mm of tread that's 9 years old is near the end of its life anyway.
- Poor repairs. A plug pushed in from the outside is not a proper repair, and neither is a repair in the sidewall or shoulder.
- Mismatched pairs. Two different part-worns on one axle can mean different grip, wear and handling.
Investigations by Trading Standards and tyre safety campaigners have repeatedly found part-worns on sale that break the rules: missing markings, illegal repairs and serious damage.
Are they actually cheaper?
Often less than you'd think. The fair comparison is the price per millimetre of usable tread: the tread above the 1.6 mm legal limit.
| Example | Price | Tread | Usable | Per usable mm |
|---|---|---|---|---|
| New budget tyre | £60 | 8 mm | 6.4 mm | £9.38 |
| Part-worn | £30 | 5 mm | 3.4 mm | £8.82 |
| Part-worn | £25 | 4 mm | 2.4 mm | £10.42 |
Example prices only. Fitting costs and real prices vary.
In this example the 4 mm part-worn costs more per mm of usable tread than a new budget tyre. You'll also pay for fitting twice as often, and you won't get a new tyre's full grip in the wet. A part-worn mainly makes sense as a short-term fix, for example to get through an MOT before you sell a car.
To work this out yourself: price ÷ (tread depth − 1.6).
Checklist before you buy
- Look for "PART-WORN" on the sidewall. No marking means walk away: the seller is breaking the law.
- Check the date code with the tyre age checker. Over 6 years old, think twice. Over 10, don't buy.
- Measure the tread in several places across and round the tyre. It must be at least 2 mm everywhere, and ideally well above.
- Ask to see it inflated and run your eyes and hand over both sidewalls, inside and out, for bulges, cracks and cuts.
- Look inside for repairs, patches or signs of being run flat (a ring of worn or crumbly rubber on the inner sidewall).
- Check the size, load index and speed rating match your car. See how to read a tyre sidewall.
- Buy matching pairs for an axle: same size, ideally the same model and similar tread.
- Get a receipt that says "part-worn". It helps if you need to complain later.
When to avoid part-worns completely
- On a high-performance car, or where you regularly drive fast on motorways
- On run-flat tyres, where hidden damage from running deflated is impossible to rule out
- On a vehicle that carries heavy loads, such as a van, motorhome or caravan
- If the seller won't let you inspect the tyre before it's fitted
If you've been sold an illegal part-worn
Report it to Trading Standards through the Citizens Advice consumer helpline. Selling a part-worn that breaks the rules is an offence, and reports help Trading Standards target rogue traders. If the tyre is already fitted and you're worried, have it checked by a different tyre fitter straight away.