MOT FAQs: How Long It Takes, Driving After a Failure, and What Fails Most Often

We get asked the same handful of MOT questions almost every day at the counter, so here are straight, honest answers to the three that come up most.

How long does an MOT take?

A standard Class 4 MOT (cars and small vans) takes around 45 to 60 minutes on the ramp. Class 7 MOTs, for larger vans, usually take a little longer because there are more checks to get through. If your car needs a repair afterwards, we'll give you a realistic time estimate before we start — most straightforward jobs like bulbs, wiper blades or a single brake component are sorted the same day.

Can I drive after an MOT failure?

It depends on two things: what the fault was classed as, and whether your old MOT certificate has already run out.

If any fault is recorded as 'dangerous', the car cannot legally be driven at all until it's fixed — not even to get it repaired elsewhere. If the faults are only 'major' or 'minor' and your previous MOT certificate is still valid, you're legally allowed to keep driving until that certificate expires, though we'd always advise against it if the fault affects brakes, steering or tyres. If your old certificate has already run out, the only legal journey left is to a pre-booked MOT or repair appointment.

We always tell you plainly which category applies to your car before you leave, so you're never guessing.

What fails an MOT most often?

Nationally, the most common reasons cars fail are lighting and signalling (a blown bulb is the single biggest cause), tyres (tread depth or damage), brakes, suspension components worn from age or corrosion, and anything affecting the driver's view of the road, such as worn wiper blades or a cracked windscreen. Most of these are quick, low-cost fixes if they're caught before the test rather than during it.

A quick check of lights, tyre tread and washer fluid the week before your MOT catches a surprising number of avoidable fails.

Booking an MOT with us is £39. MOT walk-ins are usually welcome Monday to Friday 8:00am–6:30pm or Saturday 9:00am–4:30pm, but call or WhatsApp 07311 226 868 first to check we've got space, at Unit 1D, 6 Greycaine Road, Watford WD24 7GP.

💰 Money-saving tip: book your MOT alongside a Full Service for just £15 (instead of £39), or completely FREE when booked with a Major Service.

💰 See our full MOT + Service discount details →

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