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Top 10 MOT failures and how to avoid them

Top 10 MOT failures and how to avoid them

A friendly pre-MOT checklist based on AutoRank's latest common-defect data. Most of the big ones are visible, cheap to check, and easier to sort before test day.

Based on AutoRank's live top-defects feed and overview metrics refreshed on May 19, 2026. Counts are recorded defect entries, not unique vehicles.

836.3m MOT tests in the snapshot
1.86bn defect records analysed
May 19 latest MOT import

A quick word on the numbers

The most common entries in the AutoRank defect feed are not obscure faults. They are the kind of things many drivers can spot before test day, including damaged glass, weak lamps, low tyre tread, handbrake issues and warning lights. A careful walk-round will not catch everything, but it can save you from the easy fails.

MOT records often split faults by side and exact position, which is why left and right examples can both appear in the chart. Treat that as a useful prompt to check the whole car, not just the single part named in the table.

The raw top 10 defects in the feed

MOT wording is very literal, so nearside and offside faults appear as separate entries.

1
Windscreen damage 1,600,336
2
Parking brake efficiency 929,886
3
Nearside front position lamp 890,682
4
Offside front position lamp 831,883
5
Nearside number plate lamp 720,832
6
Offside number plate lamp 714,661
7
Nearside front tyre tread 705,259
8
Engine MIL warning 572,634
9
Offside front tyre tread 568,681
10
Offside front coil spring 568,036

How to avoid the top 10

1

Windscreen damage

1,600,336 entries

Small chips, cracks and scuffs often get ignored until the tester has a proper look at the screen.

What helps Repair chips early, clean the glass inside and out, and check the swept area before test day.

2

Parking brake efficiency

929,886 entries

A weak handbrake can creep up gradually, especially on cars that do a lot of short journeys.

What helps Try it on a safe slope, listen for dragging brakes, and get adjustment or worn parts checked before the MOT.

3

Nearside front position lamp

890,682 entries

Side lights are easy to miss in daylight, and one dead bulb can look minor until it becomes an MOT fail.

What helps Switch the lights on and walk around the car. If one side is out, check the other side too.

4

Offside front position lamp

831,883 entries

The same simple bulb problem appears again because MOT records split left and right faults.

What helps Replace tired paired bulbs together if access is easy. It is usually cheaper than a retest hassle.

5

Nearside number plate lamp

720,832 entries

Number plate lamps live in the muckiest part of the car, so bad bulbs and dirty lenses are common.

What helps Check them at dusk or against a wall, wipe the lens, and make sure the plate can be read clearly.

6

Offside number plate lamp

714,661 entries

Another left and right split, with the same fix. Make the rear plate properly visible.

What helps Tap the lamp housing gently, look for flickering, and sort loose holders before the test.

7

Nearside front tyre tread

705,259 entries

Front tyres work hard, and uneven wear can hide on the inner edge where you rarely look.

What helps Use a tread gauge or the 20p check across the full width. If one edge is low, check tracking and suspension.

8

Engine MIL warning

572,634 entries

The engine management light is not background decoration. If it is on, the tester has to take it seriously.

What helps Read the fault code, fix the cause, and give the car a proper run before the MOT if emissions work has been done.

9

Offside front tyre tread

568,681 entries

This mirrors the nearside tyre entry and points to the same basic problem, worn rubber on a busy axle.

What helps Check all four tyres, including the inner shoulders, sidewalls, cuts, bulges and pressures.

10

Offside front coil spring

568,036 entries

Broken coil springs can be hard to spot from outside, but they show up a lot in MOT defect records.

What helps Listen for clunks, look for a car sitting unevenly, and ask a garage to inspect the springs if the ride feels wrong.

The ten-minute check before you book

  • All exterior lights work, including number plate lamps.
  • Tyres have enough tread across the full width.
  • No warning lights stay on after the car starts.
  • Wipers clear properly and the washer bottle is full.
  • The windscreen is clean, with chips repaired if needed.
  • The parking brake holds firmly on a gentle slope.
  • The car sits level and does not clunk over bumps.
  • Brake feel is normal and the car does not pull to one side.