Lights
Walk around your car and check every light works: headlights (dipped and full beam), rear lights, brake lights, indicators (front and rear), hazard lights, reverse lights, and number plate lights. Bulb failures are one of the most common reasons for MOT failures and cost less than £5 to fix yourself on most cars.
Ask someone to help you check the brake lights, or reverse slowly towards a reflective surface.
Tyres
Check tread depth across all four tyres — the legal minimum is 1.6mm across the central three-quarters. Use the 20p test or a tread depth gauge. Also look for cuts, bulges, or sidewall damage. Check tyre pressure while you're at it — underinflated tyres can affect emissions readings and handling checks.
Windscreen
Any chip or crack in the driver's line of sight (a 40mm zone in front of the driver) will fail. A chip anywhere in the swept area of the wipers larger than 10mm is also a fail. Chips smaller than 10mm outside the swept area are typically recorded as an advisory. Get chips repaired before the test — it's far cheaper than a new windscreen.
Make sure your windscreen washers work and the washer fluid bottle is topped up.
Wipers
Turn on your wipers and check they clear the windscreen effectively without streaking or juddering. New wiper blades cost £10–£20 and take minutes to fit.
Horn
Give it a quick press. If it doesn't work, it's an automatic fail.
Brakes
Find a quiet road and test your brakes at low speed. The car should pull up straight and not pull to one side. A spongy pedal, grinding noise, or vibration through the pedal suggests worn pads or a problem with the braking system — book a garage before your MOT rather than risk a dangerous fault failure.
Steering
Check for excessive play in the steering wheel. On a car with power steering, the wheel shouldn't move more than about 13mm before the wheels start to turn. Any clunking or knocking when turning could indicate a worn track rod end or suspension component.
Engine Warning Light
An illuminated engine management light is an automatic MOT fail. If the light is on, get a diagnostic check before the test to find and resolve the fault. Clearing the code without fixing the underlying problem won't work — the light typically returns within a few drive cycles.
Fluid Levels
Check oil, coolant, brake fluid, and washer fluid. A low oil level won't cause an MOT fail by itself, but an obvious oil leak or oil smoke from the exhaust will. Top everything up before the test.
Is a Pre-MOT Service Worth It?
If your car hasn't been serviced recently or you suspect it has issues, a pre-MOT inspection at a trusted garage can identify problems before the formal test. Many garages offer these for £30–£50. It's particularly worthwhile on older, high-mileage cars or if you've bought a used vehicle recently.
MOT Preparation Checklist
- All lights working (headlights, brakes, indicators, number plate)
- Tyre tread 1.6mm+ with no visible damage
- Tyre pressures correct
- Windscreen chip-free in key zones
- Wipers clearing effectively
- Washer fluid topped up
- Horn working
- No engine warning light
- No unusual noises or handling issues
- Vehicle handbook and V5C in the glove box