How the score works
Enter a registration and Bonafied reads that vehicle's full MOT history from the official government record, then distils it into one clear score. This page explains what goes into that score, and what deliberately doesn't.
What's behind the score
The scale and the tiers
Every eligible vehicle gets one score from 0 to 100, and the score places it in one of three tiers:
- Hidden Gem 90–100 — A clean history is no accident.
- Solid Find 70–89 — Sound, with a story you can read.
- Proceed with Care 0–69 — Worth understanding before you commit.
A car needs enough MOT history to be judged fairly. When there is too little on record — a car under three years old, for example, has no MOT history at all — we say so and withhold the score rather than bluff a number.
Some cars have time on record that no MOT test covers: paper history from before May 2005, time off the road, or years abroad before the car came to the UK. We can't see what happened then, and we don't guess, so the less of a car's life its tests cover, the more its score is pulled toward the middle of the scale. That cuts both ways: a partial record can't reach the top, and it can't reach the bottom either. If the missing time matters to you, ask the seller what they know about it.
What the score is not
The score is an MOT-history assessment only. It is not a valuation, and it is not a substitute for an independent vehicle history check, a physical inspection, or a professional mechanical appraisal. Write-off categories, outstanding finance and theft markers are not part of MOT data, which is why we always recommend a full history check before any purchase.
What has changed
| Version | Date | What changed | Rescore | Cohort rebuild |
|---|---|---|---|---|
| v28 | 22 Oct 2026 | A six-figure mileage reading the record shows was mistyped no longer costs points, and cars tested in Northern Ireland leave the averages. | Yes | Yes |
| v27 | 19 Oct 2026 | A single mileage reading that the readings either side contradict is treated as a recording error and no longer costs points. | Yes | Yes |
| v26 | 18 Oct 2026 | Released and withdrawn the same day. Every score was put back. | Yes, reversed | No |
| – | 9 Oct 2026 | Write-offs declared in a seller's advert are read from the whole advert. MOT scoring did not change. | No | No |
| v25 | 6 Oct 2026 | One advisory steps a clean record's credit back instead of wiping it out, and a finding counts once per test. | Yes | Yes |
| v24 | 5 Oct 2026 | A short clean record can reach 100, a long gap is no longer counted twice, and three kinds of advisory we were missing now count. | Yes | Yes |
| v23 | 28 Sep 2026 | How much of a car's life its MOT record covers is measured in time, not in number of tests. | Yes | Yes |
Rescore: every stored score was worked out again on the new version. Cohort rebuild: the averages we compare each car with were worked out again.
Versions before v23 date from before our public launch on 25 August 2026.
Ready to try it? Score a car, or read more about Bonafied.