MOT prep: the home checklist to pass first time
You can avoid many MOT failures with a few checks at home: make sure no warning lights stay on, every bulb works, tyres are above the 1.6 mm legal limit, and the wipers, washers and screenwash all work. The most common MOT failures are lighting, tyres and suspension.
Why a quick pre-check pays off
A large share of MOT failures are for simple, avoidable things: a blown bulb, a worn wiper, a warning light left on. Ten minutes of checks before you book can turn a fail and a retest into a straight pass, and saves you the cost and hassle of going back.
The home checklist
Warning lights: start the car and check no warning lights stay lit. An illuminated engine management light, airbag or ABS light is a fail.
Lights: walk around with the headlights, sidelights, indicators, brake lights, fog and reversing lights on. Replace any blown bulb.
Tyres: check tread is above the 1.6 mm legal minimum across the middle three-quarters, and look for cuts, bulges or uneven wear.
Wipers and washers: the blades must clear the screen without smearing, and the washers must squirt. Top up the screenwash.
Screen and mirrors: no large cracks or chips in the driver's view, and both door mirrors and the rear-view mirror present and secure.
Number plates: clean, secure, correctly spaced and readable, front and rear.
Horn, seatbelts and brakes: the horn works, seatbelts latch and retract, and the brakes feel firm with no warning light.
Exhaust: no excessive smoke, no obvious blowing or loose sections.
Warning lights and the MOT
This is the one people miss. An illuminated engine management light (MIL) is a major defect and an automatic MOT failure, and the same applies to the airbag, ABS, brake and power-steering warning lights. If any of these stay on after starting up, get the cause read and fixed before your test.
When to book
In the UK you can have the MOT done up to a month (minus a day) before it expires and keep the same renewal date, so there is no downside to testing early. If you spot a problem in your checks, that head start gives you time to fix it without driving on an expired certificate.
Frequently asked
What fails an MOT most often?
Lighting and signalling, tyres, and suspension are consistently among the most common MOT failure reasons, and many of them are simple checks you can do at home before booking.
Does a warning light fail an MOT?
Yes. An illuminated engine management light, airbag, ABS, brake or power-steering warning light counts as a major defect and fails the MOT. Fix the cause before your test.
Can I MOT my car with the engine management light on?
You can present it, but it will fail: an illuminated engine management light is an automatic MOT failure. Have the cause read and fixed first.
How early can I get my MOT done?
Up to one month (minus a day) before it expires while keeping the same renewal date, so testing early carries no penalty and gives you time to fix anything found.