Compare up to 5 used cars by MOT history (free)

When you are choosing between two or three used cars, a single MOT look-up is not enough. You need the same facts, side by side: pass and fail history, advisories, mileage trend and how often the same defects keep coming back. Used Car Checker lets you compare up to five UK registrations on the homepage for free. This guide explains what to compare, how to read the differences, and where free MOT data stops.

Why compare before a private sale

Private sales move quickly. Sellers often have more than one interested buyer, and it is easy to fall for the car that looks tidiest in the photos. MOT history is one of the few independent records you can check before you travel. Comparing two candidates on the same evening often shows that the cheaper car has a long string of advisories, or that the dearer one has cleaner tests and steadier mileage. That comparison costs nothing and can save a wasted viewing.

Official MOT results for cars, motorbikes and vans in Great Britain are available for tests since 2005 through the DVSA record. You can also check them on GOV.UK’s MOT history service. Our tool reads the same class of data and adds a side-by-side view plus a reliability score so patterns are easier to spot.

Dealers sometimes provide their own history print-outs. Still run your own check. You want the primary record, not a cropped screenshot that omits last year’s advisories. Comparing registrations yourself also means you can re-check the night before you travel, in case a fresh test has been added.

What to put side by side

• Latest result and expiry. A current pass matters, but so does how close the next test is. A car with three weeks left may need work soon after purchase.
• Pass/fail pattern. Occasional fails that were fixed cleanly are common. Repeated fails for the same system (brakes, corrosion, lights) suggest a car that is only just being kept legal.
• Advisories that never get fixed. Advisories do not fail the test, but the same tyre, corrosion or oil-leak note year after year means the next owner inherits the bill.
• Mileage trend. Look for steady increases. Flat or falling readings between tests are a classic clocking signal and need explaining with service paperwork.
• Reliability score. Our score summarises defect weightings. Use it as a filter, then read the underlying tests — never buy on the number alone. See how the score works.
• Retest behaviour. A fail followed by a same-day pass can mean a simple bulb. A fail followed by weeks of silence, then a pass at a different site, can mean harder repairs — ask what was done.

Worked example: two hatchbacks, same budget

Example only — invented vehicles, not real registrations. Imagine you are looking at two 2018 petrol hatchbacks at a similar price.

Car A looks dull in the advert but cleaner on paper. Car B photographs well but the MOT story says the next owner is buying deferred repairs and an imminent test. That is the point of compare: you are not choosing the prettiest listing, you are choosing the lower risk of surprise bills.

In the example, Car B’s mileage jump also needs a story. Maybe it sat for months then did motorway work — or maybe the odometer reading is wrong. Either way you would not travel to view Car B first. Start with Car A, and only revisit Car B if the price drops enough to cover tyres, brakes and a proper corrosion inspection.

How to run the compare tool

1. Open the compare view on the homepage.
2. Enter each registration (up to five).
3. Wait for each history to load — do not refresh mid-way.
4. Scan fail reasons and advisories first, then mileage, then the score.
5. Shortlist cars worth viewing; drop any with unexplained mileage drops or dangerous defects that were “fixed” with no documentation.

We do not permanently store the plates you enter for marketing. Lookups hit government APIs and may be cached briefly for performance. See the privacy policy.

What if one vehicle has little or no MOT history?

Cars under three years old often have no MOT yet — that is normal under UK rules for most class 4 vehicles, which need a first test by the third anniversary of registration (GOV.UK: Getting an MOT). For older vehicles, a missing history can mean an import, a long SORN period, or a registration change. Treat gaps as questions for the seller, not as a clean bill of health.

If one car in your compare set is nearly new and the other is eight years old, do not treat “no advisories” on the new car as a quality win. They have not been stress-tested by annual inspections yet. Lean on service history, warranty remaining and a physical inspection instead.

Limits versus a paid HPI-style check

Free MOT compare will not show outstanding finance, stolen markers or insurance write-off categories. Those need a paid history report. Use free compare to eliminate weak cars, then spend on a finance/write-off check only for the one you intend to buy. Our MOT vs HPI guide sets out the split clearly.

Buying sequence that works

Run free MOT history on every contender. Compare the shortlist. View only the cars that survive that filter. On the day, match the V5C, VIN and odometer to the history. Only then pay for a finance and write-off report if the purchase is large enough to justify it. Finish with insurance and tax before you drive home. That order keeps spend on the cars that deserve it.

If you want a printable walk-through for the viewing itself, use our used car checklist. For a narrative walk-through of one invented hatchback from advert to decision, see the worked buying example. For defect categories in plain English, read what advisories mean and red flags in MOT history.

Frequently asked questions

When compare disagrees with the advert

Online adverts often say “full service history” or “long MOT”. Compare those claims with the DVSA record. A “long MOT” that was passed yesterday after a fail for corrosion is not the same as a clean pass with nine months left. If the advert mileage and the latest MOT mileage disagree, stop and ask for an explanation before you set off.