MOT Advisories And Failures: What They Mean And What To Do Next

MOT Failures And Advisories At A Glance

As of November 2026, GOV.UK says a vehicle fails its MOT (Ministry of Transport test) if the test lists "dangerous" or "major" problems. "Minor" problems and "advisory" notes appear on a pass or a fail but do not cause a fail on their own.

The Four Categories In One Table

Check an MOT now

Who Sets These Rules?

The MOT scheme is run by the DVSA (Driver and Vehicle Standards Agency) for Great Britain. The detailed rules testers follow are in the DVSA's MOT inspection manual, published on GOV.UK.

This page is independent and is not affiliated with DVSA, DVLA or GOV.UK, so use the official sources linked at the end to confirm anything that affects a decision. Northern Ireland has a separate scheme run by the DVA; see our Northern Ireland MOT guide.

What This Page Covers

It explains these topics, in roughly this order:

• Defect categories and what each one means.
• Whether you can drive after a fail.
• Retest rules and fees.
• How to read advisories.
• The most common failure areas by component.
• Emissions and warning lights.
• Pre-MOT checks.
• How to challenge a result.

Booking, prices and penalties for having no MOT sit on other pages.

What Happens If You Fail An MOT?

If your car fails its MOT (also searched as "what happens if my MOT fails" or "what happens if I fail my MOT"), the result is recorded on the national MOT database, you get a list of the dangerous and major defects, and the car needs those items repaired and retested before it can pass. You do not get a new certificate until it passes.

Here is what follows, in order:

1. You get the failure details. The test centre can give you a refusal certificate (VT30), and the result also shows online in the vehicle's MOT history.
2. Your old MOT, if any, is unchanged. A fail does not cancel a certificate that is still in date, and it does not extend one either.
3. You decide whether you can drive it. You can drive the car away only if the current MOT is still valid and no dangerous defect was listed. Otherwise it must be repaired first, apart from driving to a repair or a pre-arranged test.
4. You repair the dangerous and major items. At the same centre or anywhere else.
5. You get a retest. A partial retest within 10 working days, or a full retest after that. See the retest section below.
6. Or you challenge it. If you think the fail was wrong, you can appeal to DVSA within 14 working days.

See the booking and fee guide

What Counts As An MOT Failure?

An MOT failure is a test result where at least one defect is graded dangerous or major. The tester records the result in the national MOT database, and you can see it afterwards in the vehicle's MOT history.

Is A Fail The Same As "The Car Is Unsafe"?

Not always. A major defect means the vehicle does not meet the legal standard on the day, but it may still be usable for a short, sensible journey to a repair.

A dangerous defect is different: the vehicle presents an immediate risk and should not be driven.

What Is The Difference Between A Refusal Certificate And A Fail?

They are the same event. When a vehicle fails, the test centre can issue a "refusal of an MOT test certificate", known as the VT30. GOV.UK says to ask the test centre for it, and the result also appears online. Our MOT certificate guide explains the paper forms.

Does A Fail Affect The Next Test Date?

A fail does not give you a new expiry date. Your old MOT, if still valid, keeps its expiry. A pass is what creates a new certificate. If you are unsure about timing, see MOT due date rules.

The Four Defect Categories Explained

Since 2018 the MOT has graded faults in four tiers. GOV.UK's result page lists dangerous and major as fail items and minor and advisory as items to monitor or fix later. The inspection manual applies the grading to each component.

What Is A Dangerous Defect?

A dangerous defect is a fault that is a direct and immediate risk to road safety or has a serious impact on the environment. The result is a fail and the vehicle must not be driven until it is repaired.

In the manual, examples include:

• A brake fluid level that cannot be seen at all.
• Insufficient tyre tread.
• A steering wheel likely to become detached.

What Is A Major Defect?

A major defect is a fault that may affect safety, put other road users at risk or have an impact on the environment. It is a fail. Examples from the manual include:

• A registration plate that is illegible.
• A non-working wiper.
• A missing headlamp.
• An ABS warning lamp showing a malfunction.

What Is A Minor Defect?

A minor defect has no significant effect on safety or the environment. The vehicle passes, but the item is recorded and should be repaired soon. Examples in the manual include:

• Brake fluid slightly under the minimum mark.
• A damaged rack gaiter.
• A faulty hazard tell-tale.

What Is An Advisory?

An advisory is a note that something is worth watching, such as early corrosion or a tyre approaching the legal limit. It does not affect the result. Advisories are covered in detail in later sections.

Can A Tester Pass Something They Would Rather Fail?

The tester must apply the manual's thresholds. Where the manual says to "pass and advise" in borderline cases, such as when a tester cannot tell whether what they feel in a tyre cut is the cords or a foreign object, they record an advisory instead of a fail.

That is why two cars with similar wear can get different notes.

Dangerous Defects

Dangerous defects are the highest grade. The vehicle fails and there is no legal basis to treat it as a normal road vehicle until it is fixed.

What Is Classed As A Dangerous MOT Failure?

A dangerous failure is any defect that is a direct and immediate risk to road safety. Under the DVSA manual this includes:

• Insufficient tyre tread.
• A bulge or lump from tyre structural failure.
• All stop lamps missing.
• Smoke likely to obscure other road users' vision.

Which Common Faults Can Be Dangerous?

The manual grades several everyday faults as dangerous when they reach a threshold:

• Tyre tread below the legal minimum.
• Tyre separation, lifted tread or exposed cords.
• Brake fluid not visible at all in the reservoir.
• Stop lamps that stay on after the brake is released, or all stop lamps inoperative.
• A turning door likely to open inadvertently.
• Any defect in an LPG, CNG, LNG or hydrogen fuel system.
• Excessive corrosion that is likely to affect steering or braking.

Can The Same Fault Be Major Or Dangerous?

Yes. Severity depends on degree. Brake fluid slightly below the minimum mark is minor, significantly below is major, and not visible at all is dangerous.

A tester decides on the day, so a car can move up a grade between visits if the fault worsens.

Major Defects

Major defects are the most common cause of a fail because they cover a wide range of items, from a blown bulb to a defective warning system.

Why Are Major Defects So Broad?

The manual assigns "major" to anything that could affect safety or the environment but is not an immediate danger. That includes:

• Missing mirrors.
• An inoperative horn.
• Seat belt buckles that do not work.
• Emissions above limits.
• A malfunction lamp showing a fault.

Do I Need To Fix Every Major Defect To Pass?

Yes. All dangerous and major items on the failure list must be resolved. Minor and advisory items do not need to be, though fixing them at the same time can save a second visit.

Fixes must be done before a retest, covered in the retest section below.

Can I Disagree With A Major Defect?

You can discuss it with the test centre immediately and, if you still think the failure was wrong, appeal to DVSA. Do not repair anything before the appeal ends, because the repair destroys the evidence. See the appeals section later on this page.

Minor Defects

A minor defect is recorded but the car passes. Minor items are often the early version of a future major.

Do Minor Defects Fail An MOT?

No. A minor defect does not fail the MOT. It is printed on the pass certificate as a defect for you to repair at your convenience, and it stays in the vehicle's online history.

Are Minor Defects The Same As Advisories?

They are separate categories, although both appear on a pass. A minor defect is a fault that exists and has been graded. An advisory is an observation, such as wear that has not yet reached a threshold. Used-car buyers should read both.

Why Fix A Minor Defect At All?

Because many minors become majors at the next test. A slightly low power steering fluid level is minor today; an empty reservoir is major. Fixing it now is usually cheaper than an enforced repair plus retest.

What Are MOT Advisories?

MOT advisories are notes added by the tester for things that are not yet a failure but may need attention. People searching "mot advisories", "check mot advisories" or "mot advisory meaning" are usually trying to decide if a car has hidden costs coming.

How Are Advisories Different From Failures?

An advisory has no effect on whether the car passes. It does not need repair for the MOT. Nobody can stop you driving because of an advisory alone, but it is a record that the tester saw something worth monitoring.

Are Advisories Legally Binding?

No. GOV.UK describes them as items to monitor or fix later. Still, if a car is later involved in a collision and an advisory covered the relevant component, an insurer or investigator could consider that you knew about the problem. This is general information, not legal advice.

Where Do Advisories Appear?

They appear in two places:

• On the paper certificate given at the test centre.
• In the online MOT history for the vehicle.

Our MOT history checker guide shows how to view them by registration number.

Do Advisories Expire?

They are not removed after a set time. Each test has its own list, so a repair shows as an advisory missing from the next test. If the same advisory repeats year after year, the part has probably not been repaired.

Pass, Pass With Advisories Or Fail: Reading The Result

GOV.UK shows two official outcomes: pass and fail. The phrases "pass with advisories" and "pass with minor defects" are everyday shorthand. The detail is on the record.

What Does A Plain Pass Look Like?

A pass means no dangerous or major defects were found. A pass can still list minor defects and advisories, and when it does, treat them as a to-do list rather than good news about every component.

What Does A Fail Look Like?

A fail lists at least one dangerous or major defect. It may also list minor and advisory items. GOV.UK says you can ask the test centre for the refusal certificate (VT30) and check the result online.

How Do I Tell Which Items Caused The Fail?

Look at the category label next to each item. Only those marked dangerous or major caused the fail. If an item has no label, check the printout or your online record, or ask the tester to point to the entry.

Can You Drive A Car That Has Failed Its MOT?

You can drive a failed car away only if its current MOT is still valid and no dangerous problems were listed, according to GOV.UK. Otherwise you must repair it before driving, apart from limited exceptions such as driving to a repair or to a pre-arranged MOT test.

The decision runs in this order:

1. Check for dangerous items. If any were listed, do not drive the car.
2. Check the old MOT. If it is still valid and nothing is dangerous, you may drive it, provided it stays roadworthy.
3. Check for expiry. If the old MOT has run out, drive only to a repair or a pre-booked test.

If The Old MOT Is Still Valid And The Fail Is Major

You may drive it, but the car must meet the minimum standards of roadworthiness at all times. If your old MOT is still valid, you can take it away for repairs, and GOV.UK stresses you could be fined if it is not roadworthy. In practice, a failed brake light or horn is not a reason to take a long journey.

If The Old MOT Has Expired

GOV.UK says that if the MOT has run out you cannot drive or park on the road, except to take the car to or from a repair, or to a pre-arranged MOT appointment. The fine for driving with no valid MOT can be up to £1,000. Details on penalties are in our rules and exemptions guide.

If A Dangerous Defect Was Listed

Do not drive it, even if the old MOT is still valid. GOV.UK says driving a vehicle that failed for a dangerous problem can bring a fine of up to £2,500, a driving ban and 3 penalty points. Arrange recovery or repair at the test centre if they offer it.

Does My Insurer Care?

Insurers can refuse claims where a vehicle is unroadworthy. Confirm your policy terms with the insurer and keep the failure sheet showing the defect.

Read the rules and penalties

Driving Home After A Fail: Worked Examples

These examples use made-up vehicles to show how the rules apply. They are illustrations, not legal advice.

Example: Valid Old MOT, Major Tyre Defect

Example: Expired MOT, Minor Lamp Failure

Example: Dangerous Brake Fluid Defect

Example: What If There Are Several Failures?

The most serious one decides the rule. One dangerous item among five majors means the whole vehicle falls under the dangerous rule.

What Happens Straight After A Fail

Immediately after a fail the tester gives you the failure details and the refusal certificate. You then have to choose one of three routes:

• Repair at the same centre.
• Repair elsewhere.
• Challenge the result.

What Do I Do In The First Hour?

Work through these steps:

1. Read the list. Note every dangerous and major item.
2. Ask which items are dangerous. This decides whether you can drive.
3. Ask for a written estimate. Ask whether the centre can repair the car.
4. Check the old expiry. Look up your old certificate's expiry date in the MOT history so you know if you can legally drive it.

Should I Authorise Repairs On The Spot?

Only if you are comfortable with the price. You can decline, take the list elsewhere and get other quotes. Our booking and cost guide covers comparing garages and spotting upselling.

Where Does The Result Go?

Into the national database. Anyone can look up the history of a plate, so the fail remains visible even after a pass. Used-car buyers often look at past fails, which is why a clean repair record matters.

Selling Or Scrapping A Car That Failed

You can sell a car with a failed MOT, but you must be honest about it. Buyers who search "sell mot failure car" are often dealers or scrap yards.

Can I Sell A Car That Failed Its MOT?

Yes. GOV.UK does not prohibit selling a failed car. State clearly that it failed and list the defects. Selling it as roadworthy when you know it is not could create legal problems, so seek advice if unsure.

Who Buys Failed Cars?

Several kinds of buyer:

• Private buyers who want a project.
• Dealers.
• Salvage buyers.
• Scrap buyers.

Offers reflect repair cost. Compare several, because quotes vary widely.

Should I Repair Before Selling?

It depends on repair cost versus the price difference between a car with and without a fresh MOT. Get a quote for the fail items and compare it against the likely uplift.

What About Scrapping?

If the car is beyond economic repair, an authorised treatment facility can scrap it. Tax and SORN rules apply; see the MOT and tax guide.

Check MOT and tax

MOT Retest Rules

An MOT retest is a second inspection after a fail. As of November 2026, GOV.UK's "Retest after a repair" page sets three routes:

• Leave the vehicle at the test centre.
• Return it by the end of the next working day.
• Take it away and come back within 10 working days.

Anything else is a full retest at the full fee.

See the fee table

What Are The Retest Rules At A Glance?

Which Retest Rules Do People Mix Up?

Most confusion comes from "free retest". It is only free in the first two rows above. If you take the car away and come back later in the 10 working days, the centre may charge a partial fee. Always ask for the price before you leave.

Does The Retest Rule Depend On The Test Station?

GOV.UK's wording refers to "the same test centre" for the free next-working-day route. A different centre treats it as a new test. The 10 working day partial route is described for repairs generally, but check with the centre you plan to use.

Partial Retest Fees

A partial retest only re-inspects the items that failed. GOV.UK does not publish a fixed price for it on the retest page, so do not trust any figure you have not been quoted.

How Much Is A Partial Retest?

GOV.UK says you "may be charged a partial retest fee" if you take the car away and return within 10 working days. The retest page does not state an amount, so ask the test centre for the exact price. For the maximum full fee for a car, see our booking and cost guide.

Is A Partial Retest Ever More Than The Full Fee?

The full test fee is a maximum set in law. GOV.UK says test stations cannot charge more than the maximum, and for most Class 4 vehicles including cars that figure is £54.85 as of November 2026. A partial fee should not exceed it; if a quote seems high, compare centres.

Do Centres Advertise Free Retests?

Many do, in line with the left-at-centre or next-working-day rules. Read the small print about:

• Which items are covered.
• What happens if you take the car elsewhere for repairs.
• Whether any time limit applies.

The Free Retest Next Working Day

The next-working-day route is the narrowest free retest. GOV.UK says you will not pay again if you return the vehicle to the same test centre before the end of the next working day, but only for a partial retest of listed items.

Which Items Qualify?

GOV.UK lists items such as:

• Mirrors and horn.
• Lamps and seat belts.
• Seats.
• Windscreen and wipers.
• Wheels and tyres.

Some items, like stairs and emergency exits, apply only to class 5 vehicles. If your failure was brakes or emissions, it does not qualify for this route.

What Counts As The Next Working Day?

A working day excludes weekends and bank holidays. A car failing on a Friday afternoon would need to be back by the end of Monday, unless Monday is a bank holiday, in which case the next working day is Tuesday. Always confirm the centre's opening times.

What If I Only Fix Part Of The Failure?

The centre re-inspects the listed items. Anything still failing means another fail result. Fix everything on the list before returning, to avoid wasting your free slot.

How Long Do You Get For An MOT Retest?

You get 10 working days for a partial retest if you take the car away or leave it at the centre. After that, GOV.UK treats the retest as a full test with a full fee.

How Is 10 Working Days Counted?

Count Monday to Friday, skipping bank holidays, starting the day after the fail. A bank holiday in between pushes the deadline back by a day.

What If Parts Are Delayed?

The deadline does not extend for slow parts. If you cannot make it, you will need a full retest. Order parts promptly and tell the centre if you are close to the limit.

Read the GOV.UK retest page

Does The Retest Window Apply If I Change Garages?

GOV.UK's description of the 10 working day route says the vehicle is taken away for repairs and brought back; it refers to the original test result. Ask any new centre whether they will treat it as a partial retest. They may insist on a full test.

Retest In A Different Place

You can repair a failed car anywhere and then book a full test elsewhere. The partial concession mostly benefits those returning to the same centre.

Can I Use A Different Test Centre For The Retest?

Yes, but expect a full test and a full fee. GOV.UK only describes partial retests in relation to returning to the original test centre.

Is There Any Advantage To Repairing Elsewhere?

Often price. Dealers and independent garages differ greatly, so getting three quotes can offset a lost partial concession. Our guide to booking an MOT discusses comparing centres.

Do Chain Names Change The Rules?

Rules are the same, but chains publish their own retest policies. Searches like "halfords mot retest" or "kwik fit retest mot" are about each firm's wording. Treat it as an offer on top of the law and check it before you pay.

How Long Does An MOT Retest Take?

A partial retest checks only the failed items, so it is usually quicker than a full test. GOV.UK does not publish an official duration for either, so ask the centre when you book.

Why Does A Partial Retest Vary In Time?

Because it depends on the items:

• Re-checking a lamp takes minutes.
• Re-checking brakes or emissions needs equipment set-up and a run-up.

Ask when booking.

Should I Wait Or Drop Off?

If the centre needs the car for repairs too, drop it off. If it is a simple retest, many centres will do it while you wait.

Getting Repairs Done After A Fail

You choose who repairs your car. The test centre does not have to be the garage that fixes it.

Should I Use The Test Centre For Repairs?

It is convenient and guarantees the free partial retest in most cases. But you should compare prices. A quote and a clear list of the work should be provided in writing.

What Should A Repair Quote Include?

A good quote lists:

• Parts and labour.
• VAT.
• A time estimate.
• The warranty period.
• Whether the retest fee is included.

Photographing the failed part helps if you need to compare.

What If The Repair Is Too Expensive?

Consider selling the car as a non-runner, scrapping it, or fixing only what is needed. See "Selling or scrapping a car that failed" earlier on this page.

How To Check MOT Advisories Online

Checking advisories is done through the official GOV.UK MOT history service using the vehicle's registration number. You can search "check mot advisories" and land on GOV.UK, which is free.

What Do I Need To Check Advisories?

The registration number of the vehicle. For ownership checks you may also use the V5C logbook details, but advisories are public for any plate. The page shows:

• Test date and result.
• Mileage.
• Advisories and minor defects.
• Reasons for failure.

Our home page guide walks through each field.

Can I Check Advisories On A Car I Do Not Own?

Yes. The MOT history is public for the registration number. Used-car buyers often do this before viewing a vehicle.

How Far Back Does The History Go?

The online record does not cover every year equally, and older paper-era tests may be missing or less detailed. Our MOT history guide explains what the record includes and how to interpret gaps.

Check MOT advisories free

How To Read An MOT Advisory

Advisory text is free-form written by the tester, so wording varies. Learn the key patterns to translate them.

What Do Common Phrases Mean?

Common wording translates like this:

• "Slightly" means mild.
• "Corroded" is surface or structural depending on the item.
• "Insecure" means loose.
• "Worn" means approaching limits.
• "Play" means looseness.

Extra words like "nearside" or "offside" tell you the side: nearside is the kerb side in the UK (left), offside is the driver's side (right).

How Do I Tell If An Advisory Is Urgent?

Look at the component and the verb. An advisory on brake pipes or steering is more urgent than one on a bumper scuff. If unclear, take the car to a garage with the advisory list.

What About The "Funny" Advisory Notes People Share?

Social media posts about odd tester comments are common, but they are anecdotal. Because the field is free text, wording can be informal. Judge by content, not by humour, and never assume an odd phrase means the issue is trivial.

Which Advisories Should You Fix First?

Prioritise by these two tests:

• Safety first.
• What is most likely to cause a fail next year.

A simple ranking works well.

Fix These First

How Should I Record Advisories?

Make a short list with date, component and quote. Cross off items as you repair them. A tidy service record helps resale.

Advisories When Buying A Used Car

For used-car buyers, advisories are negotiation tools and risk signals. The history may show a pattern across several years.

What Should I Look For In The History?

Four warning signs:

• Repeated advisories on the same component.
• A jump in failed items.
• Long gaps between tests.
• Mileage anomalies.

Our home page guide explains reading mileage in the history.

Does An Advisory Mean I Should Not Buy?

No. Many cars have advisories. The question is whether the repair cost is realistic and priced into the deal.

Can I Use Advisories To Negotiate?

Yes, with evidence. Get a quote for the advisory items and ask the seller to reduce the price or fix before sale.

Check a used car

Do Minor Defects And Advisories Affect Insurance Or Tax?

They do not affect the MOT result, and tax depends on having a valid MOT, not on a clean sheet. Check your insurer's terms.

Will A Minor Defect Raise My Premium?

We have no verified evidence that insurers price from MOT history, but policy terms commonly require the vehicle to be roadworthy. Ask your insurer if unsure.

Does An MOT Pass With Defects Allow Tax Renewal?

Yes. A pass is a pass. See our MOT and tax guide for the dependency between the two.

Common MOT Failure Reasons By System

The DVSA manual is organised into numbered sections, and failures fall into these areas. This page does not publish failure-rate figures because we cannot verify current ones here; DVSA and GOV.UK publish official statistics if you need them.

Which Systems Does The MOT Check?

The manual covers:

• Identification of the vehicle (plates and VIN).
• Brakes and steering.
• Visibility.
• Lamps and electrical equipment.
• Axles, wheels, tyres and suspension.
• Body structure.
• Other equipment such as seat belts and airbags.
• Nuisance (noise and emissions).

GOV.UK also says the test does not cover the condition of the engine, clutch or gearbox.

What Are The Most Common Things That Will Fail An MOT?

In general terms, lamps, tyres, brakes, suspension, visibility items and emissions are the areas drivers meet most often, because they involve wear parts and bulbs. For exact numbers, search DVSA's published MOT statistics rather than relying on forum lists.

Which Fault Types Are Easiest To Prevent?

The easy ones:

• Bulbs.
• Wiper blades and washer fluid.
• Tyre pressures.
• Horn.
• Number plates.

A quick walk-round can find most of these in under ten minutes.

MOT Tyre Rules

Tyre rules are among the most searched topics for this page ("mot tyre rules", "tyre rules for mot"). The DVSA manual is explicit, which makes tyres one of the easiest areas to self-check.

What Is The Legal Tyre Tread Depth For An MOT?

For a typical car, the primary grooves must be at least 1.6mm deep across the central three-quarters of the tread and around the full circumference. Insufficient tread is graded as a dangerous defect in the DVSA manual.

What Vehicles Use A Different Tread Limit?

The manual sets 1.0mm for some vehicles, and 1.6mm for ordinary cars.

For motorcycles and vans see our motorcycles, vans and EVs guide.

Do Secondary Grooves Count?

No. The manual says secondary grooves and sipes are ignored when measuring, and grooves containing wear indicators count as primary. That is why a tyre can look fine but fail where the main grooves are worn.

Read the motorcycle and van guide

Tyre Damage: Cuts, Bulges And Lumps

Tyre damage is judged on whether it exposes the internal structure. Cosmetic scuffs are treated differently from structural damage.

Is A Cut In A Tyre An MOT Failure?

It is if the ply or cord can be seen without touching the tyre, whatever the size of the cut. A cut that reaches the ply or cords is a major defect. If the cords can only be felt, not seen, it still fails when the cut is longer than 25mm or 10% of the section width (whichever is greater).

Is A Bulge Or Lump A Failure?

Yes. A lump, bulge or tear caused by separation or partial structural failure, including lifted tread rubber or exposed or damaged cords, is a dangerous defect. A bulge on the sidewall usually means internal damage after a kerb strike or pothole.

Is A Nail In A Tyre An MOT Failure?

Not automatically. The manual tells testers that before failing a cut, they must make sure what they can feel is the tyre cords and not a foreign object (such as a stone or a nail head lodged in the cut). If the tester is not sure, they should pass and advise. A nail or screw that has not caused a cut reaching the ply is usually not a fail by itself, but it can lose air, so repair it.

What About Tyre Cracking?

Cracking in the sidewall is a general wear pattern. Deep cracking exposing cords would be assessed as a cut or structural failure. Light surface cracking is more likely to be an advisory.

Other Tyre Defects That Cause A Fail

Beyond tread and damage, the manual lists categories that surprise owners.

Can Mixed Tyres Fail An MOT?

Yes. Different sizes on the same axle, or different structures such as radial and cross-ply on the same axle, are major. Run-flat and conventional tyres may share an axle, though this is not recommended.

Can Under-Inflation Fail?

An obviously under-inflated tyre is a minor defect, so it should not fail by itself. But low pressure often goes with other damage, so inflate and check.

How Old Can A Tyre Be?

The tyre-age rules we found in the manual (tyres over 10 years old, identified by the date code) apply to buses, coaches and minibuses, not ordinary cars. Check the manufacturer's guidance for age advice on your tyres. Keyword searches such as "mot tyre age limit cars" return mixed claims, so rely on the manual.

Spare Tyre And The MOT

People often ask "do you need a spare tyre for an MOT". The answer is straightforward and it appears in the manual.

Do You Need A Spare Tyre To Pass An MOT?

No. The manual states that only road wheels fitted at the time of inspection are checked. A missing spare is not a failure.

Is The Spare Tyre Checked In An MOT?

No. If a spare tyre is defective, the tester advises the presenter, but it is not a test failure. Many modern cars carry a repair kit instead.

Should I Keep A Spare Anyway?

For safety, yes, if your car has space. That is separate from the legal test.

Tyre Pressure Warning Lights (TPMS)

TPMS (tyre pressure monitoring system) checks apply to some newer cars. The test covers the system, not the pressure itself.

Is A TPMS Light An MOT Failure?

It can be. The manual says the check applies to M1 vehicles first used on or after 1 January 2012, and a malfunctioning or obviously non-working TPMS is a major defect. If the lamp is on simply because a tyre is low, the tester may add advisory information rather than fail.

Can You Fail An MOT On Tyre Pressure?

Not for pressure alone, as the manual treats "obviously under-inflated" as minor. But a faulty TPMS system is major. Fixing a flat or refilling usually clears the lamp.

Which Vehicles Are Excluded From The TPMS Check?

The manual excludes:

• Motor caravans.
• Ambulances.
• Hearses approved as M1 with a gross vehicle weight over 2,500kg.

Brakes And The MOT

Brakes are checked in every MOT. Searches such as "are brakes checked on mot" and "does mot check brakes" have a clear answer: yes.

What Does The MOT Check On The Brakes?

The manual covers:

• Pedal or lever condition and travel.
• Pads and linings.
• Discs and drums.
• Pipes and hoses.
• Master cylinder and servo.
• Cables and linkages.
• Brake fluid.
• The performance of service, secondary and parking brakes.

Performance is measured on a roller brake tester, plate tester or decelerometer.

What Brake Efficiency Is Required?

For a car first used on or after 1 September 2010, the service brake must reach 58% efficiency. For cars first used before that date it is 50%. The secondary brake needs 25% and the parking brake 16% for most vehicles, according to the manual.

Which Brake Faults Are Major Or Dangerous?

Examples from the manual:

Book your MOT

Is A Brake Fluid Warning Lamp A Failure?

If illuminated or defective, it is minor. Fluid significantly below the minimum mark is major.

ABS And Brake Warning Lights

ABS (anti-lock braking system) lamps are a frequent search ("abs light mot failure").

Is An ABS Light An MOT Failure?

Yes. The manual grades a non-working ABS warning device, or one showing a malfunction, as major. An ABS system that has been obviously removed is also major, and ABS cannot legally be removed from vehicles first used on or after 1 January 2010.

Will The ABS Light Come On And Go Off?

On most cars it lights at ignition and then goes out. If it stays on, the system has a fault such as a wheel speed sensor problem. Have it diagnosed before the test.

Does The Handbrake Light Matter?

The manual separately covers the parking brake performance. A brake fluid warning lamp that is illuminated is minor. If the parking brake does not meet its efficiency threshold, that is a performance failure.

Lights And The MOT

Light failures are cheap to fix and easy to spot. Lamps get a long section of the manual.

Why Do So Many Cars Fail On Lights?

Three common reasons:

• Bulbs fail without warning.
• Lenses crack.
• Aim drifts over time.

The manual grades many lamp faults as major when the lamp is missing, inoperative or more than half the light sources are out.

What Are The Headlamp Rules?

The key points:

• A matched pair of main beam and a matched pair of dipped beam are required.
• Light sources out up to half on an LED lamp is minor.
• Missing, inoperative or over half out is major.
• Wrong colour, incompatible light source, or an aim that is out of limits is major.

What Are The Stop Lamp Rules?

The grades run as follows:

What About Indicators And Hazards?

The key points:

• Indicators must be amber.
• A multi-source lamp up to half out is minor.
• Missing, inoperative or over half out is major.
• Flash rate must be 60 to 120 per minute.
• An indicator tell-tale missing or inoperative is minor.

Daytime Running Lights, Fog Lamps And Reversing Lamps

These are often misunderstood. The manual sets rules depending on the date the vehicle was first used.

Is A Reversing Light An MOT Failure?

Yes, on vehicles first used on or after 1 September 2009 (excluding quadricycles and Class 3), a reversing lamp that is inoperative is a major defect. It must come on automatically when reverse is selected. Older vehicles are not required to have one.

Can Daytime Running Lights Fail An MOT?

DRLs (daytime running lamps) where fitted as original equipment on M1 vehicles first used on or after 1 March 2018 must be white and no more than two. Inspectors check them as position lamps under the manual. A faulty DRL on a covered vehicle can be a defect.

Are Fog Lamps Required?

One rear fog lamp, red, on the centre or offside is required for vehicles first used on or after 1 April 1980. An obligatory rear fog lamp missing, or any fog lamp inoperative, is major.

Are Side Lights An MOT Failure?

Position lamps (sidelights): missing, inoperative or over half out is major. Up to half out on a multi-source lamp is minor.

What About Number Plate Lamps?

If the only lamp or all lamps are not working, that is major. One of several lamps out is minor.

Number Plates And The MOT

Number plates are a frequent cause of failure that is entirely avoidable. Search interest includes "mot test number plates" and "number plate mot failure".

What Are The MOT Rules For Number Plates?

Both plates must be:

• Fitted and showing the same registration.
• Clean enough to read.
• Free from being obscured, excessively damaged or delaminated.
• Of the correct size, stroke width, spacing and font.

Rear plates need black on yellow and front plates black on white, for vehicles made from 1 January 1980.

What Number Plate Defects Fail?

Every registration plate defect in the manual is major:

• Plate missing or likely to fall off.
• Inscription missing or illegible.
• Incorrect registration.
• Plate not conforming to the requirements.

A plate with a tint, film or honeycomb background on newer vehicles counts under that last point.

Do I Have To Measure The Characters?

No. The manual says inspectors judge by eye and "do not have to physically measure the characters or their spacing". Obviously wrong spacing or italic fonts will still be noticed.

What About The VIN?

The VIN (Vehicle Identification Number) must be present, complete and legible on vehicles first used on or after 1 August 1980. A missing, illegible or obviously falsified VIN is major, and so is more than one different VIN.

Visibility: Windscreen, Wipers And Mirrors

Visibility items are in section 3 of the manual. They include damage to the screen, wipers, washers and mirrors.

How Big Can Windscreen Damage Be?

The limits depend on the zone:

• Directly ahead of the driver: a swept area 290mm wide, centred on the steering wheel, where damage over 10mm in diameter is a problem.
• Rest of the swept area: the limit is 40mm.

Damage only fails if it significantly affects the driver's view.

Do Wipers And Washers Matter?

Yes:

• A wiper that does not operate or is missing is major.
• A defective blade is minor.
• A missing blade or one that clearly fails to clear the screen is major.
• Washers that do not work or do not supply enough fluid are major.

What Mirror Faults Fail?

The grades are:

• A missing obligatory mirror is major.
• Slightly damaged or loose is minor.
• Inoperative, excessively damaged, insecure, or not giving an adequate view to the rear is major.

Can A Repaired Windscreen Pass?

The manual says repaired windscreens are judged solely on whether the repair interferes with vision.

Steering And Suspension

Steering and suspension wear slowly, so advisories often precede a fail. These systems are in sections 2 and 5.

What Steering Faults Can Fail?

The grades are:

• Excessive play is major.
• Excessive ball joint wear is major.
• An electric power steering warning lamp indicating a fault is major.
• A steering wheel likely to become detached is dangerous.
• Steering rack gaiter damage and slight fluid weeping are minor.

How Much Steering Play Is Allowed?

Free play at the rim of a 380mm wheel is limited to:

• 13mm for rack and pinion steering.
• 48mm with several joints between wheel and rack.
• 75mm for other types.

Limits are adjusted for different wheel sizes.

Find your due date

Can Power Steering Fluid Fail The Car?

Level below minimum is minor, and an empty reservoir is major. Testers check through a sight glass without removing the cap.

What About Suspension?

The manual covers springs, shock absorbers, bushes and joints. Leaking dampers and worn bushes are typical advisories or majors depending on the degree.

Body Structure And Corrosion

Corrosion is judged by how it affects the structure, not by how it looks. Appendix A of the manual covers the criteria.

When Does Rust Fail An MOT?

Corrosion is major if vehicle rigidity is significantly reduced, and dangerous if steering or braking is likely to be affected. Body panels corroded or damaged to the point of likely injury when grazed are major.

What Are The Rules On Doors, Boot And Bonnet?

The grades are:

• A door that will not open with its control or close properly is major.
• A turning door likely to open by itself is dangerous.
• A boot lid or tailgate that cannot be secured closed is major.

Do Towbars Get Tested?

Yes:

• A towball or coupling with excessive wear, damage or corrosion is major.
• One likely to fail is dangerous.
• A towbar that obstructs the number plate or a lamp is minor, or major if the plate is unreadable.

What About Fuel And Exhaust Leaks?

The grades are:

• A leaking or missing filler cap is major.
• Excessive leaking or a fire risk is dangerous.
• An exhaust fume leak into the cabin is major.
• One that endangers occupants' health is dangerous.

Seat Belts, Airbags And Other Equipment

Section 7 of the manual covers seat belts, airbags, horn, speedometer and electronic stability control.

What Seat Belt Faults Fail?

A missing statutory belt, loose anchorage, damaged webbing, faulty buckle or retractor are all major. A belt that is damaged near a load-bearing structure likely to detach in a collision is dangerous.

Read the DVSA manual

Is The Airbag Light A Failure?

Yes. The SRS (supplementary restraint system) malfunction indicator lamp showing a malfunction is major. A switched-off passenger airbag, or a lamp showing it is disabled, is not a defect.

Do Horn And Speedometer Matter?

Yes:

• An audible warning that does not work is major.
• A speedometer that does not work or is not illuminated is major.

Is ESC Checked?

Yes. An ESC (electronic stability control) warning lamp that clearly indicates a malfunction is major, as are damaged wheel speed sensors or a damaged ESC switch.

The MOT Emissions Test

The exhaust emissions check is part of the MOT because the test covers environmental standards as well as safety. GOV.UK describes the MOT as checking that a vehicle meets "road safety and environmental standards". Section 8 of the DVSA manual covers noise, exhaust emissions, fluid leaks and the engine malfunction indicator lamp.

Why Do MOT Tests Include An Exhaust Emission Test?

Because vehicles must meet environmental standards as well as safety standards. Testers measure what comes out of the exhaust, and check that emission control equipment is present and unmodified, so that cars do not pollute more than they were designed to.

What Does The Tester Actually Measure?

The measurements depend on fuel type:

They also look for visible smoke, leaks in the induction or exhaust and any missing or tampered emission control equipment.

Is The Emissions Test The Same For Every Car?

No. Limits depend on:

• Fuel type.
• Age of the vehicle.
• For catalyst petrol cars, vehicle-specific figures from the in-service exhaust emission standards.

The manual says default limits apply if there is no exact match.

Petrol Emissions Limits And Failures

Petrol cars are tested at idle and a raised fast idle. The manual sets basic test figures for vehicles without vehicle-specific data.

What Are The Petrol Limits?

The basic test figures are:

• At fast idle (2,500 to 3,000 rpm): CO up to 0.2%.
• At fast idle: HC up to 200 ppm.
• At fast idle: lambda between 0.97 and 1.03.
• At idle: CO up to 0.3%.

Full catalyst tests use vehicle-specific limits, so these are guide values only. Ask the garage for your car's own limit.

Why Does A Petrol Car Fail On Emissions?

Typical causes are:

• A failing catalytic converter.
• A faulty lambda or oxygen sensor.
• A rich fuel mixture.
• An induction or exhaust leak.
• An engine that has not reached operating temperature.

The manual treats emissions above the limit, a lambda outside range, or a test that cannot be completed as major.

What Can I Do Before The Test?

Three practical steps:

1. Service the car if it is due.
2. Check for warning lights and fix the cause of any that are lit.
3. Drive it for a good run so the engine and catalyst are hot.

Clear fault codes only after fixing the cause, not to hide it.

Can I Reduce CO And HC With An Additive?

Additives are sold for this purpose but results vary and we cannot verify claims. Fixing the root cause, such as a worn sensor or misfire, is the dependable route.

Diesel Smoke Limits And The MOT

Diesel cars are tested for smoke density by accelerating the engine several times and measuring opacity.

How Is The Diesel Smoke Test Carried Out?

The sequence runs like this:

1. Warm the engine. It must be at least 80°C, or normal operating temperature if lower.
2. Purge. The tester holds the engine at about 2,500 rpm for 30 seconds.
3. Accelerate. The tester carries out up to 6 accelerations.
4. Read the result. It passes if the first reading is 60% or less of the limit, or the mean of the first three, or any three consecutive readings, is at or below the limit.

What If The Plate Shows A Lower Limit?

Cars that carry a manufacturer's plate value are tested against that value, with 0.05 added by the tester. So the plate figure matters for newer cars.

What Smoke Is Dangerous?

Smoke of any colour likely to obscure other road users' vision is graded dangerous. Smoke above the limit is major.

Diesel Particulate Filters (DPF) And The MOT

A DPF (diesel particulate filter) traps soot. The MOT checks it by looking for smoke and signs of tampering.

Does The MOT Check The DPF?

Yes. During the smoke test the tester checks for visible smoke of any colour. Visible smoke from a vehicle with a DPF is a major defect. A DPF with evidence of tampering is also major.

Can I Remove My DPF?

Removing or modifying emission control equipment is a major defect in the manual, and the manual says to reject a filter that has been cut open and rewelded unless the presenter can show a valid reason such as cleaning. Beyond the MOT, check the law with DVSA or a legal adviser before modifying anything.

How Do I Stop A DPF Causing A Fail?

Good habits:

• Take regular longer runs so the filter can regenerate.
• Keep to the service schedule.
• Do not ignore a DPF warning lamp.

If the lamp is lit and the car is in limp mode, get it diagnosed. A blocked DPF often reflects short journeys.

Can A Regeneration Run Before The Test Help?

A sustained motorway run may help if the filter is partly loaded. It cannot fix a failed or removed filter, so treat it as a preparation step only.

What To Do If Your Car Failed The MOT On Emissions

Searches such as "car failed mot on emissions what can i do" show how common worry is. The answer depends on the fuel type and the fault.

What Are The First Steps?

Start here:

1. Read the failure sheet. See whether the fail was a reading above limit, a test that could not be completed, or a lamp or equipment fault.
2. Get the cause diagnosed. Do this rather than guessing.
3. Repair, then retest.

The fail gives you the results; a garage can find the reason.

What Are Typical Fixes?

See what a fail means

Can I Drive It Away?

GOV.UK's rule applies: if the current MOT is valid and no dangerous defect was listed, you may drive it, though it must remain roadworthy. A diesel producing smoke that obscures other drivers is dangerous, so do not drive that.

Does A CO2 Fail Exist?

The manual sets limits for CO and HC on petrol cars and smoke opacity on diesel. We could not verify a separate CO2 pass or fail limit in the manual, so check with the garage if your sheet mentions CO2.

Warning Lights And The MOT

Warning lights, also called tell-tales, are checked on the dashboard against the lamp rules in the DVSA manual.

Which Warning Lights Fail An MOT?

Is An Engine Management Light An MOT Failure?

Yes, on the vehicles covered. The manual grades a MIL that is inoperative or showing a fault as major. It applies to:

• Petrol and gas or bi-fuel vehicles with four or more wheels (hybrids included).
• Diesel vehicles with four or more wheels, subject to first-use dates.

Kit cars, amateur-built vehicles and American pickups are exempt.

Can A Car Pass With The Engine Light On?

Not if the lamp is showing a fault on a covered vehicle. Fix the fault, then confirm the lamp goes out after starting. Clearing codes just before the test does not help if the fault returns.

Is A Service Light An MOT Failure?

A service reminder is not listed among the warning lamps we found in the manual, so it is not graded as a defect there. Treat it as a maintenance prompt.

Is The Tyre Pressure Light A Failure?

A TPMS system that is malfunctioning is major. If it lit because a tyre is low, the tester may add advisory information. Check pressures first.

Pre-MOT Checks You Can Do Yourself

A pre-MOT check is a walk-round and dashboard check before the real test. Searches like "pre mot checklist" and "pre mot checks" are among the highest on this page.

What Should Be On A Pre-MOT Checklist?

Work through these items, where the manual gives clear thresholds:

• Lights, indicators and horn.
• Wipers and washer fluid.
• Tyre condition and pressures.
• Number plates.
• Mirrors and seat belts.
• Windscreen damage.
• Dashboard warning lamps.
• Brake fluid level.
• A look underneath for leaks.

How Long Does A DIY Check Take?

A basic walk-round can be done in a few minutes with a helper to watch the lights. Allow longer if you check tread depth and fluids.

How Do I Check Lights Alone?

Reverse up to a wall or a reflective surface, or use a helper. Test these in turn:

• Dipped and main beam.
• Sidelights and fog lamps.
• Indicators and hazards.
• Stop lamps and reversing lamps.

Remember number plate lamps.

How Do I Check Tread Depth?

Use a tread gauge across the central three-quarters of the tread, in the main grooves, at several points around the tyre. The 1.6mm minimum applies to ordinary cars.

What Should I Look For Underneath?

Look for:

• Fluid drips.
• Damaged brake pipes.
• Split rubber boots.
• Loose exhaust sections.
• Obvious corrosion.

If you cannot safely get underneath, ask a garage.

Book your MOT

Getting A Professional Pre-MOT Inspection

You can ask a garage for a pre-MOT check or a health check before the test. Searches include "pre mot inspection" and "can you get a pre mot check".

Is A Pre-MOT Check Worth Paying For?

Yes, in any of these cases:

• The car is older.
• It has unexplained noises or warning lights.
• The last MOT listed several advisories.

A garage can raise a ramp, check wear and quote repairs before the official test. Price comparison is covered in the booking guide.

Can The Garage Also Repair It?

Often, and that avoids a second trip. But remember that a garage doing a pre-check is not the DVSA tester and cannot guarantee the result.

Should I Book The Real Test Straight After?

Some centres combine them. Check the retest policy of the centre, because failing in front of the same tester usually gives you the strongest retest terms.

Appeals And Disputes About A Result

GOV.UK explains how to challenge a result. It is not a substitute for a retest if you simply want the work done.

Can I Appeal An MOT Failure?

Yes. You can appeal to DVSA if your vehicle failed and you think the failure was wrong, or if it passed and you think it should have failed. Discuss the result with the test centre first. GOV.UK says you should not have any repairs made until the appeal process has finished.

What Is The Deadline?

Send the complaint form to DVSA within 14 working days of the test for a failed MOT you dispute. For a pass you think should have failed, GOV.UK gives 3 months if the problem is corrosion-related; confirm other deadlines on the GOV.UK page, because the wording is easy to misread.

What Happens After I Appeal?

The process runs like this:

1. DVSA contacts you. It says it will do so within 5 days to discuss the appeal.
2. Possible recheck. It may recheck the vehicle and send an inspection report listing defects.
3. Fee. If a recheck is ordered after a failed-test appeal you must arrange a date and pay the full test fee again; if the appeal succeeds, the fee is refunded.

Can DVSA Get Me Compensation?

GOV.UK says DVSA cannot help you get a refund or compensation from the MOT centre. For action against a centre, GOV.UK points to Trading Standards, personal legal proceedings or the police.

What If The Record Is Wrong Rather Than The Test?

Mistakes on the record are a separate process. See our MOT certificate guide for corrections.

Open the certificate guide

MOT Failure Myths

Myths cost people money and cause unsafe driving. Each one below is checked against GOV.UK or the DVSA manual.

Myth: A Failed Car Can Never Be Driven

It can, if the current MOT is still valid and no dangerous defect was listed, per GOV.UK. It must still be roadworthy.

Myth: Advisories Mean A Fail Next Year

Not necessarily. They signal a watch-list. Many advisories remain for years without becoming a fail, but ignoring brake or steering ones is risky.

Myth: You Need A Spare Tyre To Pass

You do not. The spare is not checked as a road wheel.

Myth: A Retest Is Always Free

Only in defined cases. Taking the car away and returning within 10 working days may attract a partial retest fee.

Myth: The Engine Light Is Just A Warning

On covered vehicles a MIL showing a fault is a major failure.

Myth: The MOT Checks The Engine And Gearbox

GOV.UK says the test does not cover the condition of the engine, clutch or gearbox. Emissions and leaks are checked.

Buying A Car That Failed Its MOT

Searches such as "mot failure cars for sale" and "buy mot failure cars" show people hunt for bargains. Risk is higher, so be systematic.

How Do I Check The Failure Reasons?

Look up the registration in the online history and read the fail items and the categories. A dangerous brake defect and a blown bulb are very different purchases. Our history checker guide walks through the steps.

What Should I Price In?

Add up these costs:

• Parts and labour.
• The retest fee.
• Tax status.
• Delivery.

Do not count on a free partial retest unless you have confirmed terms with a centre.

Can I Drive It Home?

Only under GOV.UK's limits: valid MOT with no dangerous items, or travel to a repair or pre-booked test. Dangerous items mean transport on a trailer. The MOT and tax guide covers tax and insurance questions when buying.

Check MOT and tax

Fleet And Business Angles

Fleet owners deal with many vehicles and can lose revenue when one fails.

How Should A Fleet Handle Failures?

Three habits:

• Keep a list of defects by vehicle.
• Repair them before retest windows close.
• Track repeat advisories, which often indicate driver or maintenance issues.

Should Fleets Use Pre-MOT Checks?

Daily walk-round checks catch bulbs, tyres and leaks. Combine with scheduled servicing so test day is a formality.

Where Can I Find Official Failure Statistics?

DVSA publishes MOT testing statistics on GOV.UK. We do not quote failure rates here because we have not verified current figures; use the official release for exact numbers.

Where To Check The Rules Yourself

Official sources override this page. The most useful are:

• GOV.UK's "Getting an MOT" pages.
• The "Retest after a repair" page.
• The "Test result appeals and problems" page.
• The DVSA MOT inspection manual.

As of November 2026 the manual page showed an update dated 14 October 2026; check it for changes before relying on any threshold above.

What If The Rules Change?

Thresholds and fees can change. Where this page quotes a figure, it records the source and the date it was checked. Treat anything else as general guidance.

What If I Am In Northern Ireland?

The DVA runs a separate scheme. Retest and failure details may differ, so use the Northern Ireland MOT guide and NI Direct.

Read the Northern Ireland guide

How To View MOT Advisories Online

To view MOT advisories, use the official GOV.UK Check MOT history service and enter the vehicle's number plate. Each recorded test lists what failed and what had minor problems, and advisories are shown against the test they were recorded on.

How Do You View MOT Advisories Step By Step?

1. Go to the Check MOT history service from GOV.UK.
2. Enter the registration number of the vehicle.
3. Open the latest test and read the failure, minor defect and advisory lists.
4. Open earlier tests to compare, so you can see which items were repaired and which keep coming back.

What Extra Detail Do You Need?

GOV.UK says you need the number plate. For tests in England, Scotland and Wales you also need the 11-digit number from the V5C log book if you want to see where each test was done. History for cars, motorcycles and vans goes back to 2005, as of November 2026.

Can You See Advisories From The Paper Certificate Instead?

Yes, if the test centre printed them, but the online record is easier to keep and compare. If an advisory is missing from the paper copy and the online record, ask the test centre to check the result.

Check MOT advisories

How Long After An MOT Fail Do You Have To Fix It?

You have 10 working days if you want a partial retest. After that you need a full retest and the full fee. Separately, there is no deadline for fixing a failed car if you do not need it on the road, but you cannot drive it if it is unroadworthy or has no valid MOT.

What Are The Two Different Deadlines?

• Retest deadline: 10 working days for a partial retest, or the end of the next working day for the free listed-items route at the same centre.
• Driving deadline: your old MOT's expiry date. If it is still valid and nothing dangerous was listed, you can keep driving until it runs out, but you cannot pass that date without a new pass.

What If You Cannot Fix It In Time?

You can still repair the car later and book a full MOT. Nothing stops you doing that, but you pay the full fee and the car must not be driven on the road without a valid MOT except to a repair or pre-arranged test. The retest rules above explain how working days are counted.

What Are MOT Tyre Rules In The Test?

In the MOT tyres are checked for tread depth, damage, size, rating and fitment. For an ordinary car the minimum is 1.6mm in the main grooves across the central three-quarters of the tread and around the full circumference.

What Do Testers Look At On A Tyre?

• Tread depth in the primary grooves.
• Cuts, bulges, lumps and tears, including exposed cords.
• Speed and load ratings against the minimum for the vehicle.
• Matching sizes and structures on each axle.
• Valves and seating on the rim.
• Whether the tyre fouls a part of the vehicle.

Only the wheels fitted at the time of inspection are checked; the spare is not. The full table of tyre defects and their grades is in the tyre sections above.

Why Do New Cars Fail MOTs?

A car's first MOT is due three years after registration, and cars that fail at that age usually fail on ordinary wear and tear items rather than age. The DVSA does not rank causes on this page's verified sources, so we do not quote percentages.

What New-Car Fail Topics Are Worth Checking?

• Bulbs and lamps, including reversing lamps and number plate lamps.
• Tyres, which wear faster on cars that cover high mileage.
• Wipers, washer fluid and windscreen chips.
• Number plates, especially tinted, film-covered or non-standard ones.
• Warning lamps such as ABS, airbag, ESC, engine and tyre pressure monitoring.
• Brake wear on cars driven mainly in towns or on motorways.

For when the first test is due, see MOT due date rules.

How To Lower Emissions For The MOT

To lower emissions before an MOT, make sure the car is serviced, has no warning lamps lit, and is fully warmed up when the test starts. If the readings are still high, the cause is usually a worn component, so the reliable fix is a proper diagnosis rather than an additive.

What Helps Petrol Cars?

• A service with fresh spark plugs, air filter and oil if due.
• Fixing any misfire or lit engine lamp first.
• A good warm-up run so the catalyst is hot.
• Checking for exhaust or induction leaks.

What Helps Diesel Cars?

• A longer, steady run before the test so a partly loaded DPF can regenerate.
• Replacing a clogged air filter.
• Having injectors, EGR or turbo problems diagnosed if smoke is visible.

Book an MOT

Should You Fix An MOT Advisory?

You do not have to fix an advisory to pass, but you should fix any that affect brakes, steering, suspension or tyres, and watch the rest. An advisory is the tester telling you the part is not yet a fail, which makes it the cheapest moment to repair it.

How Do You Decide?

• Safety part, getting worse: fix soon.
• Wear item near its limit: budget for it before the next test.
• Cosmetic or surface note: monitor it.

Which MOT Failures Are The Most Common?

The most common failure areas are lights, tyres, brakes, suspension, visibility and emissions, and most are cheap to prevent. DVSA publishes official MOT statistics on GOV.UK if you need exact rankings.

Frequently Asked Questions

Sources And Further Reading

• GOV.UK – Getting an MOT
• GOV.UK – MOT test result
• GOV.UK – Retest after a repair
• GOV.UK – Test result appeals and problems
• GOV.UK – MOT inspection manual for private passenger and light commercial vehicles
• GOV.UK – MOT test fees