Tyre MOT failures
Tyres are among the top three failure areas and the No.1 source of dangerous defects. Unlike most failures, you can check them yourself in two minutes.
Checked against the MOT inspection manual and GOV.UK guidance · Updated November 2026
The legal tread depth
Car tyres must have at least 1.6mm of tread across the central three-quarters of the tread width, around the entire circumference. Check with a gauge or use a 20p coin: insert it into the main grooves – if the outer band of the coin is visible, the tread is close to or under the limit. Check several points round each tyre because wear is often uneven, especially on the inner edge where you can't easily see.
What the tester checks
- Tread depth and pattern across the whole tyre
- Cuts, lumps, bulges and tears, especially in the sidewalls
- Exposed ply or cord
- Tyre size and type – same size and structure (radial/cross-ply) on each axle
- Load capacity and speed rating suitable for the vehicle
- Tyre fouling the body or suspension
- Valve condition
- Re-cut tread (not allowed on cars)
- Tyre pressure monitoring system (TPMS) – cars first used from 1 January 2012
- Wheels – damage, distortion, missing or loose wheel nuts or studs
The spare wheel isn't inspected, though it must be secure if carried.
Common tyre failures
| Defect found | Usual category |
|---|---|
| Tread below 1.6mm | Major |
| Tread below 1.6mm over a large area or cords exposed | Dangerous |
| Cut over 25mm or 10% of section width, deep enough to reach the ply or cord | Major |
| Lump, bulge or tear caused by separation or failure of the structure | Major / Dangerous |
| Different sizes or structures on the same axle | Major |
| Load index too low for the vehicle | Major |
| TPMS malfunction warning on, or system inoperative | Major |
| Tyre fouling bodywork or suspension, affecting safe driving | Major |
| Wheel nut or stud missing | Major |
| Wheel nut loose | Dangerous |
The TPMS light
Every new passenger car first used from 1 January 2012 has a tyre pressure monitoring system. If the TPMS warning lamp indicates a malfunction, the car fails. Causes include a flat sensor battery (sensors last around 5–10 years), a sensor damaged during a tyre change, or a system that needs relearning after rotating wheels. Simply low pressure lighting the lamp is fixed by inflating and resetting.
Tyre age
The MOT doesn't fail a tyre on age alone. But old tyres crack in the sidewalls and between tread blocks, and serious cracking can fail. The date code is the last four digits of the DOT code on the sidewall (week and year).
Repair costs
| Repair | Typical cost | DIY? |
|---|---|---|
| Budget tyre, fitted (small car) | £50–£80 | No |
| Mid-range tyre, fitted (family car) | £80–£140 | No |
| Premium tyre, fitted (SUV / large wheels) | £140–£300+ | No |
| TPMS sensor (each, fitted and coded) | £40–£90 | No |
| Wheel alignment | £40–£80 | No |
| Wheel stud or nut | £5–£30 | Yes |
Typical UK independent garage prices including parts, labour and VAT, 2026. Main dealers and premium/4x4 vehicles cost more.