Every year, thousands of UK drivers fail their MOTs due to simple, avoidable mistakes. Despite the growing awareness of MOT requirements, the same prep errors continue to cost time, money, and convenience. In 2025, with stricter DVSA checks and more advanced testing systems in place, proper preparation is more important than ever. Let’s explore the most common MOT prep mistakes and how to avoid them.

1. Ignoring Dashboard Warning Lights

A glowing dashboard light is one of the biggest red flags for MOT testers. Whether it’s the engine management light, ABS, or airbag warning, these lights indicate underlying issues that can cause instant MOT failure. Drivers often assume minor warning lights won’t matter—but even one can lead to rejection.

Tip: Before your MOT, make sure all dashboard lights function correctly during ignition and turn off once the engine starts.

2. Forgetting Basic Fluid and Oil Checks

Low engine oil, brake fluid, or washer fluid levels are among the easiest MOT prep mistakes to avoid—yet many still neglect them. A simple top-up before the test can make the difference between a pass and a fail.

Tip: Check all fluid levels a few days before your MOT. Keeping your washer fluid filled is mandatory for road safety.

3. Poor Tyre Condition and Pressure

Tyres are one of the most common reasons cars fail MOTs. Many drivers overlook tread depth, uneven wear, or incorrect pressure. Remember, the legal minimum tread depth in the UK is 1.6mm, and damaged tyres (cracks, bulges, or cuts) are automatic fails.

Tip: Use a 20p coin to check tyre tread depth and ensure all tyres match the recommended PSI levels from your car’s manual.

4. Dirty or Broken Lights

Lights are essential for visibility and safety. Faulty or dirty headlights, brake lights, and indicators often lead to unnecessary MOT failures. It’s a quick fix that many skip during prep.

Tip: Test all your car’s lights the night before. Replace bulbs and clean lenses to ensure they shine brightly.

5. Neglecting Windscreen and Wipers

A cracked windscreen or worn-out wipers can easily fail an MOT. Even small chips in the driver’s line of sight can lead to rejection under DVSA standards.

Tip: Check your windscreen for chips and ensure your wipers clean effectively without streaking or noise.

6. Arriving with a Dirty Vehicle

This might surprise you, but cleanliness can affect your MOT result. Excess dirt can hide corrosion or make number plates unreadable. Testers may even refuse to test a filthy car.

Tip: Give your car a quick wash—especially the lights, registration plates, and underside of the vehicle.

7. Skipping the MOT Due Date Check

Many UK drivers forget when their MOT is due and accidentally drive with an expired certificate—risking fines of up to £1,000. Always confirm your MOT date in advance.

You can check your MOT status online at CheckMot.com to see when your next test is due and review your car’s MOT history.

FAQs

1. What are the easiest MOT prep mistakes to fix?

Checking tyre tread, topping up fluids, and replacing bulbs are simple DIY fixes that can help your car pass easily.

2. Can I drive to the MOT test centre if my MOT has expired?

Yes, but only if you have a confirmed MOT booking and drive directly to the test centre.

3. How early should I start preparing for my MOT?

Begin at least a week before your test. This gives you enough time to fix any issues you find.

4. Can dirty seats or interior affect my MOT result?

Not directly—but a dirty interior may give testers a poor impression and make it harder to inspect seatbelts or safety features.

Proper MOT preparation isn’t complicated—it’s about attention to detail. By avoiding these MOT prep mistakes, you’ll save time, money, and stress, ensuring your vehicle stays road-legal and safe for another year.