Understanding MOT Tests
Everything you need to know about MOT testing in the UK. Learn what gets checked, how to prepare, and what happens if your vehicle fails.
What is an MOT Test?
The MOT (Ministry of Transport) test is an annual safety and emissions check required for most vehicles over three years old in the UK. It ensures your car meets minimum safety and environmental standards to remain roadworthy.
The test examines key safety components like brakes, tyres, lights, and seatbelts, plus emissions levels. Passing an MOT doesn't guarantee your car is fault-free, but it confirms essential safety systems are working properly on the day of the test.
When Do You Need an MOT?
Three years from registration
New cars need their first MOT three years after initial registration. After that, annual tests are required. The test must be done by the anniversary date shown on your V5C.
Up to one month early
You can take your MOT up to a month before the expiry date without losing time. The new certificate will run for 12 months from the original expiry date, not from the test date.
Exemptions
Vehicles over 40 years old are exempt from MOT testing. Classic cars and some specialist vehicles may qualify. Check GOV.UK for current exemption rules.
What Gets Tested?
Lights and electrics
Headlights, indicators, brake lights, fog lights, number plate lights, and hazard lights. All must work correctly with proper beam alignment and no cracks in lenses.
Brakes
Brake performance, condition of pads and discs, brake fluid level, parking brake operation, and ABS warning lights. Brakes must stop the vehicle effectively and evenly.
Tyres and wheels
Tread depth (minimum 1.6mm across central three-quarters), tyre condition, proper inflation, wheel condition, and spare tyre if fitted. Damaged or worn tyres will fail.
Suspension
Shock absorbers, springs, and suspension mounting points. Testers check for excessive wear, damage, or corrosion. Bouncy or unstable handling indicates suspension problems.
Steering
Power steering operation, steering rack condition, excessive play, and secure mounting. Loose or worn steering components are dangerous and will fail the test.
Emissions
Exhaust emissions must meet standards for the vehicle's age. Diesel smoke opacity, catalytic converter function, and exhaust system condition including leaks or excessive noise.
Body and structure
Rust and corrosion, especially on load-bearing areas. Sharp edges, insecure panels, damaged seats, seatbelt condition and operation. Serious corrosion causes immediate failure.
Windscreen and visibility
Windscreen damage, wiper operation, washer fluid delivery, mirrors, and driver's view. Chips larger than 10mm in the swept area or cracks will fail the test.
MOT Failure Categories
Dangerous
Serious safety hazard. Vehicle cannot be driven until repaired. Examples include seriously worn brakes, severe steering problems, or major structural corrosion. Immediate repair required.
Major
Fails MOT but less severe than dangerous. Vehicle shouldn't be driven but technically can be (though illegal without valid MOT). Must be repaired and retested within 10 working days for free retest on failed items.
Minor
Doesn't affect MOT pass. Issues that should be monitored or repaired soon. Vehicle passes but problems could become major faults if ignored. No immediate action required.
Advisory
Vehicle passes, but tester notes items starting to wear. Not failures but worth monitoring. Common advisories include slight brake wear, minor oil leaks, or surface rust. Plan repairs before next MOT.
Preparing for Your MOT
Check basics yourself
Test all lights, check tyre tread and pressure, top up washer fluid, ensure wipers work, and check for visible damage. Fix obvious issues before the test.
Review previous advisories
Use MOTCompare to see last year's advisories. Address recurring issues and items that were "monitor and repair soon" warnings. This prevents predictable failures.
Clean your vehicle
Remove personal items, clean number plates, and ensure VIN is visible. A clean car makes inspection easier and shows you care for the vehicle properly.
Bring required documents
V5C registration document isn't required but helps verify identity. Some test centers ask for insurance proof. Check with your chosen garage beforehand.
What Happens if You Fail?
- You receive a VT30 refusal certificate listing all failures
- Dangerous faults mean you legally cannot drive the car
- Free partial retest within 10 working days for failed items only
- Full retest fee applies after 10 days or if you go elsewhere
- Current MOT remains valid until expiry even if you fail early test
- Driving without MOT risks £1,000 fine and invalidates insurance
Common MOT Failures
Understanding the most frequent failure points helps you prepare:
Lighting and signaling (30% of failures)
Blown bulbs, damaged lenses, faulty wiring. Simple to fix but easy to overlook. Check all lights including number plate lights before your test.
Suspension (14% of failures)
Worn shock absorbers, damaged springs, bushings. Often creates handling issues you might ignore. Professional inspection recommended if car feels bouncy or unstable.
Brakes (10% of failures)
Low brake pad material, corroded discs, brake fluid issues. Any squealing, grinding, or reduced braking performance needs urgent attention before testing.
Tyres (9% of failures)
Insufficient tread depth, damage, wrong size, incorrect pressure. Check tread with 20p coin test (outer band should not be visible in tread).
Check Your Vehicle History
View your car's complete MOT history and see previous advisories before your next test.
Check MOT History