Updated April 2026 · AI-Diagnostics-Pro · 7 min read
Nearly 1 in 3 UK cars fail their MOT — but most failures are preventable. This checklist covers everything to check before your test.
An illuminated check engine light is an automatic MOT failure. Scan for codes before booking your test — even pending codes can trigger the light during the test.
Most common MOT failure. Check headlights, brake lights, indicators, fog lights and number plate light. A £3 bulb shouldn't fail your MOT.
Legal minimum tread is 1.6mm. Use the 20p test — if the outer band is visible, the tyre is at or below the limit. Check for sidewall bulges or cuts.
Brake pedal should feel firm. Wipers must clear effectively without smearing. Horn must sound. All quick checks before the test.
Scan your car for fault codes at least a week before your MOT — that gives you time to fix anything before the test.
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