The pre-MOT checklist that catches every easy fail

Why this matters

MOT retests are charged if you bring the car back after seven days. Even within seven days, you've paid £55 for the original test, paid for the repair, lost a morning, and now have an MOT-expired car you can't legally drive (unless directly to and from the repairing garage). The 30 minutes of pre-MOT prep below saves all of that.

The seven-day-before checklist

Walk round the car methodically — 30 minutes.

• Every bulb: dipped, full, brake, reverse, indicators front + rear + side, fog, number plate light. Get a friend to confirm the brake lights while you press the pedal.
• Wipers: both front and rear. Streaking or judder = fail. New blades £15 a pair.
• Washer bottle: must be full and operational. A dry bottle is a major-category fail.
• Tyres: 1.6mm minimum tread across the central three-quarters of the band — but anything under 3mm is genuinely worn. Check sidewalls for cuts and bulges. Pressures correct.
• Registration plates: secure, legal font, no missing characters, no cracks across the digits. Faded or damaged plates fail.
• Mirrors: secure, no cracks across the glass, view unobstructed.
• Horn: actually press it. Some give up entirely over a quiet year.
• Seatbelts: all working, retracting, no fraying.
• Windscreen: any chip in the driver's swept area over 10mm = fail. Insurance usually covers free repair.

The things to check on the day before

Park-up checks the tester will do that you can pre-empt. Engine warning lights — any persistent yellow on the dashboard is a fail; clear the fault or get it diagnosed. Fluid leaks under the car — fresh oil or coolant on the driveway = inspection fail. Excessive engine smoke on cold start (especially blue or black) = emissions fail risk.

What the tester is looking for that you can't fix

Don't waste prep time on these — they need a garage. Brake performance (uneven wear or pull). Suspension play. Steering geometry. Underbody corrosion (especially around mounting points). Emissions exceedance. If you suspect any of these, book a pre-MOT inspection at a garage two weeks before the test (£25–£40) — much cheaper than a retest and you get time to fix.