What's Actually Checked in an MOT? An Ashford Driver's Guide

By Salek Tyre & Mechanic · Ashford, TW15

An MOT can feel like a mystery — you hand over your keys and hope for the best. So here's exactly what a tester checks, what they don't, and the simple things you can do beforehand to avoid an unnecessary fail.

First, the basics

In the UK, your car needs its first MOT when it's 3 years old, and then once every year after that. An MOT checks that your car meets the minimum legal standards for safety and emissions — it is not a check of overall mechanical condition or reliability.

What the tester checks

An MOT covers the parts that keep you and other road users safe, including:

• Lights — headlights, brake lights, indicators, hazards and number-plate lights all working and aimed correctly.
• Brakes — condition, performance and balance (often the biggest single area).
• Tyres & wheels — tread depth (minimum 1.6mm), condition, correct size and no dangerous damage.
• Steering & suspension — for wear, play and security.
• Seatbelts — all present, secure and working.
• Windscreen, wipers & washers — clear view of the road, no large chips in the driver's line of sight.
• Mirrors, horn & number plates — present, secure and legible.
• Exhaust & emissions — exhaust secure and emissions within limits.
• Body & structure — no excessive corrosion or sharp edges in key areas.

What an MOT does NOT check

This catches a lot of people out. An MOT does not assess the condition of your:

• Engine internals, clutch or gearbox
• Oil, coolant and other fluid levels (beyond what's needed to run the test)
• Cambelt / timing belt

That's why a car can pass its MOT and still break down a week later — the MOT and a service are two different things. A service looks after the "health" of your car; the MOT just confirms it's road-legal on the day.

The most common reasons cars fail

The good news: many MOT failures are for cheap, easily-avoided faults. The usual culprits are:

1. Lighting — a blown bulb is one of the top reasons for a fail.
2. Tyres — worn below 1.6mm or damaged.
3. Brakes — worn pads or imbalance.
4. Driver's view of the road — wiper blades worn, washers empty, or a chipped screen.
5. Suspension — worn components.

5-minute pre-MOT checks you can do

• Walk around with the lights and indicators on — replace any blown bulbs.
• Top up your screen-wash and check the wipers don't smear.
• Give the tyres a quick 20p test and check for damage.
• Make sure the number plates are clean and readable.
• Clear the boot and footwells so the tester can reach everything.