What Happens During an MOT Test? Step-by-Step Guide

Summary

• Over 100 checks: The tester looks at your brakes, lights, tyres, steering, emissions, and bodywork during an MOT.
• Takes 45-60 minutes: A standard test takes under an hour. Failures that need repairs will take longer. Check how long an MOT takes for more details.
• Results straight away: You get your pass or fail result as soon as the test is done. Results also appear online within 24 hours.

Your car needs an MOT every year once it turns three years old. It's the law in the UK.

But what actually happens when you hand over your keys? What does the tester look at? And how can you avoid a fail?

This guide walks you through every step of the MOT process. No jargon. No confusion. Just clear answers.

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When You Arrive at the Garage

When you get to the MOT centre, you'll check in at reception. They'll take your keys and vehicle details.

You can wait in the customer area or leave and come back. Most garages have a waiting room with tea and coffee.

The tester will drive your car into the testing bay. Then the checks begin.

Good to know: You can watch the test at many garages. There's usually a viewing window. It helps you see exactly what happens.

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What Gets Checked During an MOT

The tester checks over 100 things on your car. Here's a breakdown of the main areas:

Test Area	What They Check	Approx. Time
Lights and signals	All bulbs, headlamp aim, indicators, hazards, brake lights	5-10 mins
Steering	Steering wheel play, power steering, column condition	5 mins
Suspension	Shock absorbers, springs, ball joints, bushes	5-10 mins
Brakes	Brake pads, discs, efficiency, balance, handbrake	10-15 mins
Tyres and wheels	Tread depth, condition, correct size, wheel bearings	5 mins
Exhaust and emissions	Exhaust condition, noise levels, CO2 output	5-10 mins
Bodywork and structure	Rust, sharp edges, secure panels, seatbelt mounts	5-10 mins
Windscreen and wipers	Chips, cracks, wiper blades, washer fluid	3-5 mins
Mirrors	Condition, secure mounting, visibility	2-3 mins
Seatbelts	Working buckles, fraying, retraction	3-5 mins
Horn	Works properly and loud enough	1 min
Fuel system	No leaks, secure cap	2-3 mins

For a full list of every check, see our ultimate MOT guide.

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Step 1: Lights and Signals

This is usually the first thing checked. The tester walks around your car and tests every light.

They check headlights on dipped and full beam. They look at brake lights, indicators, fog lights, and number plate lights.

They also check that headlamps are aimed correctly. A misaimed headlight can dazzle other drivers.

Common fails

• Blown bulbs: This is the most common MOT fail. Always check your bulbs before the test.
• Wrong colour: Headlights must be white. Rear lights must be red.
• Broken lens: A cracked light cover will fail if it changes the light colour.

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Step 2: Brakes and Steering

Your brakes are one of the most important safety checks. The tester uses a brake roller to measure stopping power.

They check that your brakes stop evenly on both sides. Uneven brakes mean your car pulls to one side when stopping.

The handbrake gets tested too. It must hold the car on a slope.

For steering, they check for excess play in the wheel. Any looseness in the steering column is a fail.

Common fails

• Worn brake pads: Thin pads don't stop as well. Read our brake replacement guide to know when yours need changing.
• Leaking brake fluid: Any leak in the braking system is a dangerous fail.
• Loose steering: Worn joints or bushes cause too much play.

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Step 3: Tyres and Emissions

The tester checks each tyre for tread depth. The legal minimum is 1.6mm across the middle three-quarters of the tyre.

They also look for cuts, bulges, and damage. Mismatched tyre sizes on the same axle will fail too.

For emissions, a probe goes into your exhaust pipe. It measures the gases your engine produces.

Petrol cars are tested for carbon monoxide. Diesel cars are tested for smoke levels. If your engine isn't running cleanly, it will fail.

Quick tip: Take your car for a 20-minute drive before the test. A warm engine produces cleaner emissions. This can help you pass.

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Step 4: Bodywork and Interior

The tester checks your car's body for serious rust. Small surface rust is fine. But rust near key parts like seatbelt mounts is a fail.

They check your windscreen for chips and cracks. A crack bigger than 40mm in the driver's view area fails. A crack bigger than 10mm in the area swept by the wipers also fails.

Inside the car, they test all seatbelts. Each one must clip in, hold tight, and retract properly.

The horn gets a quick test too. It needs to work and be loud enough to hear.

If any dashboard warning lights are on, they may cause a fail depending on which ones.

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Getting Your Results

Once the test is done, you get your results straight away. There are three possible outcomes:

• Pass: Your car meets all standards. You get a new MOT certificate valid for 12 months.
• Advisory: Your car passes but has items that may fail next time. Keep an eye on these. Learn more about MOT advisories and what they mean.
• Fail: Your car has serious problems. It must be fixed before it passes. See our guide on what to do if your car fails.

Results also go on the DVSA database. You can check any car's MOT history online for free.

You can also use CarOwl's free MOT checker to see full results quickly.

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How to Prepare Your Car

A few simple checks before the test can save you money and time. Do these the day before:

1. Check all lights: Ask someone to help. Test headlights, brake lights, indicators, and fog lights.
2. Top up washer fluid: An empty washer bottle is an instant fail.
3. Check your tyres: Look at the tread depth and check for damage. Use a 20p coin - if you can see the outer rim, your tread is too low.
4. Test your wipers: They need to clear the screen without smearing.
5. Check your horn: Give it a quick press to make sure it works.
6. Look for warning lights: Start the engine and check the dashboard.
7. Top up your oil: Low oil can affect emissions readings.

For a full pre-test checklist, see our essential car maintenance checklist.

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The MOT test is nothing to worry about. Most cars pass first time if they're well looked after. A few simple checks at home can make all the difference.

Need to book your MOT? Do it early to get the best time slot. And remember, you can book up to a month before your due date without losing any days on your certificate.

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