The tyre still has legal tread across most of its width, but one shoulder is worn down. It's usually recorded as an advisory until the worn band drops below 1.6mm across the central three quarters of the tread — at which point it becomes a straight failure. More importantly, it's a symptom: tyres don't wear on one edge for no reason.
Wording as it commonly appears on an MOT certificate: “Tyre worn close to the legal limit on the inner edge”.
What does it mean?
The tyre still has legal tread across most of its width, but one shoulder is worn down. It's usually recorded as an advisory until the worn band drops below 1.6mm across the central three quarters of the tread — at which point it becomes a straight failure. More importantly, it's a symptom: tyres don't wear on one edge for no reason.
How serious is it?
Usually recorded as: Advisory, Major. The tester assesses the actual vehicle on the day, so your certificate is what counts.
What normally causes it?
- Wheel alignment out of specification, most often toe on the rear of a multi-link car
- Worn suspension bushes or arms letting the geometry move under load
- Running under-inflated, which wears both shoulders, or over-inflated, which wears the middle
- Kerb damage or pothole impact having knocked the settings out
What a mechanic would check
I read the wear pattern before I quote anything. Feathered edges you can feel with a hand swept across the tread mean toe error; smooth one-sided wear usually means camber. Then I check for play in the arms and bushes, because putting new tyres on a car with worn geometry just buys you the same bill again in a year.
What might need replacing
- A tyre or a pair on that axle
- Four-wheel alignment
- Suspension bushes or an arm if the geometry can't be set
Can you still drive it?
Once any part of the legal tread band is below 1.6mm the car is illegal, not just failed. Wet grip drops off long before that, so plan the replacement rather than waiting for the retest.
Repair cost
Always fit tyres in pairs across an axle, and get the alignment set at the same time — otherwise the new tyre wears out the same way.
Before the retest
Check every tyre, not just the one that failed — the legal minimum is 1.6mm across the central three-quarters of the tread, all the way round. Make sure tyres on the same axle match in size and construction, and that all wheel nuts or bolts are present and tight. Set pressures to the figure on the door shoulder or in the handbook the morning of the retest.
Retest rules
If the vehicle stays at the test centre for repair and is retested within 10 working days, a partial retest is often free; some items qualify for a free retest if you bring the car back by the end of the next working day. The exact conditions are set out on GOV.UK, so confirm with the test centre before you leave. A major or dangerous failure means the car cannot legally be driven away unless the previous MOT is still valid and nothing dangerous was recorded — check your certificate first.
Related help
More tyres and wheels failures · MOT failure decoder · Ask a mechanic about your certificate
This is general guidance from a UK mechanic, not a substitute for a physical inspection. Only the tester who inspected your vehicle can confirm what was recorded and why.