What the MOT checks
The MOT is a safety and emissions inspection. It does not cover the condition of the engine, clutch or gearbox. The tester checks:
- Lights and signals: every lamp works, is the right colour, and headlamps are aimed correctly.
- Steering and suspension: wear in joints, bushes, springs and shock absorbers.
- Brakes: performance, balance, pipes, discs and pads where visible, and the handbrake.
- Tyres and wheels: tread depth of at least 1.6mm, condition, size and type.
- Visibility: windscreen chips and cracks in the driver's view, wipers, washers and mirrors.
- Body and structure: corrosion near important parts and sharp edges.
- Seat belts and seats: condition, fixings and operation.
- Exhaust and emissions: leaks, security and the emissions test. A diesel particulate filter that has been removed is an automatic fail.
- Registration plates and VIN: legible, correct font and spacing, and a VIN that can be read.
- Warning lights: for example an airbag, ABS, power steering or engine management light that stays on.
The most common reasons cars fail
DVSA publishes MOT results every year. The same areas come up again and again.
| Area | Typical faults | Can you check it? |
|---|---|---|
| Lamps and electrical | Blown bulbs, number plate lamp out, headlamp aim, warning lights on | Yes, easily |
| Suspension | Broken springs, worn ball joints and bushes, leaking shock absorbers | Partly |
| Tyres | Tread under 1.6mm, cuts, bulges, wrong size | Yes |
| Brakes | Worn pads and discs, imbalance, weak handbrake, corroded pipes | Partly |
| Visibility | Windscreen damage, worn wipers, empty washer bottle | Yes |
| Body and structure | Corrosion near suspension mounts and sills | Partly |
15-minute checks before your MOT
- Lights. Turn on every light, including indicators, hazards, brake lights, fog lights and the number plate lamp. Use a reflection in a window or ask someone to help.
- Tyres. Check tread depth with a 20p coin (see our tread depth guide), and look for cuts and bulges on both sidewalls.
- Wipers and washers. Blades should clear the screen without smearing. Top up the washer fluid: an empty bottle is a fail.
- Windscreen. Chips over 10mm in the area in front of the driver, or 40mm elsewhere in the swept area, fail.
- Horn. One clear note.
- Seat belts. Pull each one sharply. It should lock, and the buckle should latch and release cleanly.
- Number plates. Clean, undamaged, and in the legal font and spacing.
- Warning lights. Start the car and check that every warning light goes out.
- Fluids. Top up the oil, brake fluid and screenwash. Low brake fluid can trigger a warning light, which is a fail.
- Clear the car. Remove clutter from the boot and cabin. Testers can refuse to test a dirty or overloaded car.
Use the car's MOT history
Last year's advisories are the best guide to what might fail this year. A tester who wrote "brake pads wearing thin" or "corrosion on sub-frame" is telling you what to watch. Look up the car's record on GOV.UK, and read our guide to MOT advisories and defects to understand the wording.
If your car fails
You may be able to drive away if the old MOT is still valid and no dangerous defects were found. Otherwise you can only drive to a garage for repairs or to a booked retest. See how much an MOT costs for when the retest is free.
Sources
- GOV.UK: MOT inspection manual for cars and passenger vehicles
- GOV.UK: What is tested in an MOT
- GOV.UK: MOT testing data for Great Britain
Checked against official sources on 15 October 2026. Rules and prices change, so confirm anything important on GOV.UK. Spotted something out of date? Tell us.