The Complete MOT Checklist: What to Check Before Your Test

I've been a qualified MOT assessor for a long time, and the thing that still gets me is how many cars fail on a bulb.

Not brakes. Not a structural problem. A bulb. Something the owner could have fixed for a few quid in their own driveway, ten minutes before they set off.

Lighting is the single biggest cause of MOT failures in this country, and it isn't close. Add tyres and screen wash to it and you've covered a huge slice of everything that goes wrong on test day.

So here's the whole thing. What they actually check, what to look at yourself a week before, what happens if it fails, and the bits nobody explains properly.

If you only do one walk round, do this one. It covers the most common failure points.

1. Every light and indicator works, and get someone to stand behind you for the brake lights
2. Tyre tread is comfortably above 1.6mm, with no cuts or bulges
3. Screenwash is topped up and the wipers actually clear the glass
4. No warning lights lit on the dashboard
5. No chips in the driver's line of sight
6. Horn works
7. Number plates clean, secure and legible
8. Seat belts latch and retract properly
9. Brakes stop the car evenly, with no noise and no pulling
10. Nothing hanging loose underneath and nothing blowing from the exhaust

That's it. Ten minutes, no tools, and it'll catch most of what I see fail.

Now the detail.

An MOT is a roadworthiness and emissions test to DVSA standards. It is not a service, and it doesn't tell you the car is mechanically healthy. It tells you the car met a minimum safety standard on the day.

The tester works through these areas:

• ▸Lighting and signalling
• ▸Steering and suspension
• ▸Brakes, including efficiency and balance
• ▸Tyres and road wheels
• ▸Seat belts and their anchorages
• ▸Body, structure and general items, including corrosion in specified areas
• ▸Exhaust, fuel and emissions
• ▸Driver's view of the road, including the windscreen, wipers and mirrors
• ▸Registration plates and VIN
• ▸Horn
• ▸Towbar, if fitted
• ▸Dashboard warning lamps for safety systems

What it does not check: the engine, the clutch, the gearbox, the condition of the oil, or anything else that determines whether the car will still be running next year. That's what a service is for, and the two are completely different jobs.

The big one. Check every single one:

• ▸Headlights, dipped and full beam
• ▸Side lights
• ▸Brake lights, including the high level one if fitted
• ▸Indicators front and rear
• ▸Hazard warning lights
• ▸Number plate light
• ▸Rear fog light
• ▸Reversing lights

One blown bulb is a straight fail. Most take minutes and cost a few pounds. Do them in daylight against a garage door or a shop window if you're on your own, and get someone to press the brake pedal while you look.

Also worth knowing: headlight aim is tested, and it's a common fail that nobody expects. If you've had a bulb changed and it's been put back slightly wrong, or the car's been sat loaded with a boot full of tools, it can throw the beam pattern out.

Consistently one of the top failure categories.

• ▸Tread depth must be at least 1.6mm across the central three quarters of the tyre, all the way round
• ▸No cuts, bulges, lumps or exposed cord in the sidewall
• ▸Correct pressures, in the handbook or on the door shut sticker
• ▸All wheel nuts present and tight
• ▸No damage to the wheel itself
• ▸Tyres of the same size and type across each axle

If your tread is anywhere near 1.6mm, replace it now rather than after the test. You need new tyres either way, and doing it beforehand saves you a re-test.

The 20p test is the quick version. Push a 20p coin into the main tread grooves. If you can see the outer band on the coin, the tread is too low.

The test measures brake efficiency on a rolling road, checks the brakes work evenly side to side, and checks the handbrake holds properly.

What you can check yourself:

• ▸Does the pedal feel firm, or spongy and long?
• ▸Does the car pull to one side under braking?
• ▸Any grinding, squealing or scraping?
• ▸Does the handbrake hold the car on a slope?
• ▸Look through the wheel at the disc. Deep scoring or a big lip at the outer edge is a bad sign

Any of those means get it looked at before the test, not after. We've written up the five signs your brakes need attention if you want the detail.

Your MOT will fail if:

• ▸There's damage bigger than 10mm in the driver's A zone, the area directly swept in front of the steering wheel
• ▸There's damage bigger than 40mm anywhere else in the swept area
• ▸The wipers don't clear the screen properly
• ▸The washers don't work or the bottle is empty

That last one genuinely fails cars. Top the bottle up before you go. It costs nothing.

Chips are worth repairing quickly, because they spread with temperature changes, and most insurance policies cover a chip repair with no excess.

Check for:

• ▸Excessive play in the steering wheel before the wheels move
• ▸Knocking or clunking over bumps
• ▸The car bouncing more than once after you push down hard on a corner
• ▸Visible fluid leaking down the body of a shock absorber
• ▸Split or perished rubber gaiters and bushes

Drive over a few speed bumps and listen. Suspension is one of the top failure categories and it rarely fails silently.

• ▸No holes, no blowing, nothing hanging loose
• ▸No excessive smoke
• ▸Catalytic converter present if the car was built with one
• ▸Emissions within limits for the engine type

If your engine management light is on, the car will almost certainly fail the emissions element regardless of what comes out of the pipe. Get it read first.

Diesel owners: if your DPF light has been on and you've been ignoring it, sort that before you book.

Since the rules changed in 2018, an illuminated warning lamp showing an active fault is a failure in its own right. The ones that matter:

• ▸Engine management
• ▸ABS
• ▸Airbag and restraints
• ▸Brake system
• ▸Electronic stability control
• ▸Power steering, on cars fitted with it
• ▸Tyre pressure monitoring, on cars fitted with it

Service reminders, low fuel and low screenwash lamps don't affect the test.

This is the one that catches most people, because the car drives perfectly normally with an airbag light on and after a few months you stop seeing it. Then it fails, you pay for the diagnosis and the repair anyway, and you've lost the test fee on top.

Check your dashboard a fortnight before, not the night before. Every symbol is explained in our dashboard warning lights guide, and if one's lit and you don't know why, diagnostics starts from £45.

Quick pass round the inside:

• ▸Every belt latches, releases and retracts properly, with no fraying or cuts
• ▸Driver's side mirror and one other mirror present and undamaged
• ▸Horn works and sounds like a horn
• ▸Doors open and close from inside and out
• ▸Boot and bonnet shut securely, and the bonnet prop holds
• ▸Fuel cap present and sealing
• ▸Number plates clean, secure, correct font and spacing, no fancy lettering

Worth understanding, because people panic at the wrong list.

Dangerous means an immediate risk. The car fails and you must not drive it away.

Major means it fails. You can only drive it away if the existing MOT is still valid and the car remains roadworthy; otherwise it must be repaired and re-tested first.

Minor means it passed, but the defect should be repaired as soon as possible.

Advisory means the tester is telling you something will need attention before long. Brakes at 30 per cent, a tyre getting low, surface corrosion starting. Not urgent, but next year's failure list is usually this year's advisory list.

Keep your advisories. They're the cheapest maintenance plan you'll ever be given, and acting on them at your own pace is far cheaper than acting on them under a deadline.

This trips people up constantly, so here it is plainly.

If you leave the car at the test centre for repair and it's re-tested within ten working days, the partial re-test is free.

If you take the car away, a partial re-test by the end of the next working day is free for certain listed items. Bring it back within ten working days and you can be charged a partial re-test fee.

After ten working days, you need a full test and pay the full fee again.

So don't drift. If it fails, get it booked back in while the clock is still running.

No, with two narrow exceptions.

You can drive directly to a pre-booked MOT test, and you can drive to a garage for repairs needed to pass. In both cases the car still has to be roadworthy, and you need to be able to prove the appointment if you're stopped.

There is no grace period. Not fourteen days, not any days. From midnight after the expiry date, driving it is an offence, and ANPR cameras flag expired MOTs very quickly.

The penalty is a fine of up to £1,000. If the car has a dangerous defect it rises to £2,500, three penalty points, and a possible ban. On top of that, most insurance policies require a valid MOT, so a claim could be refused even if the accident wasn't your fault.

Book early and none of this is ever your problem.

The test itself normally takes between forty-five minutes and an hour for a standard car. Longer if the tester finds something that needs a closer look.

If you're waiting, allow an hour. If repairs are needed, that's separate and depends entirely on what's failed.

Usually nothing. The tester works from the number plate and the DVSA database, and the result is uploaded automatically.

Worth having anyway:

• ▸Your V5C, if the car's details have changed recently
• ▸Last year's advisory list, so you can confirm you've dealt with anything on it

You can test up to a month minus a day before your current certificate expires and keep the same renewal date. You lose nothing by going early, and you gain weeks of breathing room if something fails.

The people who end up stuck are the ones who book the week it runs out, fail on something that needs a part ordering, and then can't legally drive the car.

An MOT is a minimum standard, tested on one day. Passing it doesn't mean the car is in good health, and I'd rather people knew that than found out the hard way in February.

The test fee is capped by the government at £54.85 for a normal car, so no garage can charge you more for the test itself. Which means the test isn't where the money is. The repairs are, and that's why it matters who's giving you the list.

If you want to know before the test rather than after it, I do a pre-MOT check for £25 covering everything on the official test. If I find something, I'll usually fix it there and then. And if something will fail but you can't afford to sort it this month, I'll tell you exactly what's critical and what can wait.

When you're ready, our MOT service starts from £40 and we collect the car from your door in Dudley and Stourbridge, and across the rest of the Black Country. If you want the money side of it, here's what an MOT really costs and what a fail actually means.