The Most Common MOT Failures (and How to Avoid Them)

Every year the DVSA publishes its testing statistics, and every year the same story repeats: around three in ten cars fail first time, and the top failure categories barely move. That's actually good news: it means most failures are predictable, and a lot of them are preventable with checks you can do on the driveway.

The usual suspects

The DVSA groups defects by category, and the leaderboard is stable year after year:

Broken springs and worn bushes need a garage, but look at the rest of that table: bulbs, tyres, wipers and washer fluid are all owner-checkable. A meaningful slice of the UK's annual failures comes down to items that cost a few pounds and five minutes.

The 10-minute pre-test checklist

Run through this the week before your test, early enough to fix what you find:

1. Lights. Walk around the car with everything switched on: headlights (dip and main), sidelights, indicators, hazards, fog lights, brake lights and the number-plate lamp. Brake lights are easiest with a helper or a reflection in a window.
2. Tyres. Check tread with the 20p test across each tyre's width, and look for cuts, bulges or perishing on the sidewalls. Don't forget the pressure: badly underinflated tyres wear their edges into failure.
3. Windscreen. Chips larger than 10mm in the driver's sweep area (or 40mm anywhere) are failures. Worn wipers that smear are too, and they cost pounds to replace.
4. Washer fluid. Genuinely: an empty washer bottle is a fail. Top it up.
5. Horn. One press. If it's feeble or silent, fix it.
6. Warning lights. Engine management, ABS, airbag and other dashboard warning lamps that stay lit are failures on modern cars. A lamp that's been "on for ages but it's fine" needs diagnosing before the test, not after.
7. Seatbelts. Pull each belt sharply to check it locks; inspect the webbing for cuts and fraying.
8. Number plates. Legible, secure, correctly spaced, and matching the car's record. (Our free car check shows the DVLA's identity record if you want to confirm.)
9. Listen. A blowing exhaust is audible long before it fails. So is a knocking suspension over speed bumps.
10. Mirrors and doors. Both external mirrors intact and adjustable; doors opening from inside and out.

What you can't easily check yourself

Brake wear beyond the visible pad, suspension components, emissions and structural corrosion need a ramp and a trained eye. If the car has carried advisories in these areas (check the history and advisory record if you're not sure), it's worth asking a garage to look at those items before the test rather than paying for a fail and a retest. Advisories are the tester telling you what's going to fail next year; our guide to MOT advisories explains how to read them.

After a fail: the practical rules

• Dangerous defect: the car doesn't move under its own power until it's repaired. No exceptions, old certificate or not.
• Major defect with a valid old certificate: you can drive it until the old certificate expires, though driving a known-defective car can still be an offence in itself if it's plainly unroadworthy.
• Retest: repaired at the same garage within ten working days usually means a free or reduced retest of the failed items only. Repaired elsewhere, you'll typically pay for a partial retest, so confirm the garage's policy when you book.

Timing helps enormously here. Book your test near the start of the one-month-minus-a-day early window (explained in our MOT due date guide), and a fail becomes an inconvenience rather than a car you legally can't drive to work on Monday.

Buying? Failures are data

If you're looking at a used car rather than preparing your own, the failure record is gold. A car that fails on brakes or suspension every couple of years is telling you how it's been maintained: reactively, at test time, rather than preventively. The full picture of how to use that record when buying is in the complete MOT guide and our understanding MOT results walkthrough.

The bottom line

MOT failures aren't random: the same five categories catch the same cars every year, and half the entries on the list are checkable at home with a 20p coin and a walk around the car. Do the ten-minute checklist a week out, deal with warning lights before the tester sees them, and book early in the renewal window so a fail never leaves you stranded.