Guides

Used-car buying guides

Plain-English guides to the three things most likely to go wrong when you buy a used car in the UK: a wound-back odometer, a hidden write-off, and finance still owing on the car. Each guide shows you what to look for in the MOT history and the full history report, and what to ask the seller.

Roughly one in sixteen UK used cars has a mileage discrepancy, and hundreds of thousands of cars on the road have been written off and repaired. None of that shows up in a listing photo. These guides are written for buyers who do not have a mechanic in the family, and every one of them ends with the exact checks you can run for free with a registration number.

How to Spot a Clocked Car From the MOT History

Key takeaway: A genuine car's MOT mileage only ever goes up. A reading that drops and stays below the earlier trend is the clearest public sign of a wound-back odometer — but a single dip that later readings rejoin is usually a keying error at the test centre, not fraud.

This guide walks through the year-by-year mileage trail on the MOT record, shows how to tell a one-off recording error from a confirmed rollback, explains the believable-annual-mileage test, and ends with a red-flags checklist to take to the viewing.

Where to find the mileage recorded at every MOT test
Recording error vs confirmed rollback — how the next reading decides it
The believable-annual-mileage test (the UK average is ~7,000–8,000 miles)
Red-flags checklist for the viewing

Read guide → · Related: What is the difference between a mileage discrepancy and a recording error?

Cat S, Cat N and Write-Off Categories Explained

Key takeaway: Cat A and Cat B cars must never return to the road. Cat S (structural) and Cat N (non-structural) cars can, and can be perfectly good buys — but only at a write-off price, with a proper repair, and with the history declared. Cat C and Cat D are the pre-2017 equivalents of S and N.

This guide explains what each category actually means, why a repaired Cat S is not automatically dangerous and a Cat N is not automatically fine, what evidence to demand before buying one, and why a write-off record never shows on the free MOT history — only on a full history check.

Cat A, B, S and N — what each category actually means
Why a Cat A or B car must never return to the road
Buying a repaired Cat S/N: repair evidence, inspection, insurance and resale
Why a write-off doesn't show on the free MOT history

Read guide → · Related: What do Cat S, Cat N, Cat A and Cat B mean?

Outstanding Finance on a Used Car: How to Check Before You Buy

Key takeaway: If a car still has finance owing, the lender — not the seller — may legally own it. Outstanding finance does not appear on the V5C or the MOT record; the only way to know is a dedicated finance check before you pay.

This guide explains who really owns a financed car, why the V5C logbook proves less than you think, what Section 27 “innocent purchaser” protection does and doesn't cover, and how to protect yourself — check first, get the finance settled first, and never pay on a promise.

Why the registered keeper isn't always the legal owner
Will you actually lose the car? Innocent-purchaser protection explained
Why holding the V5C logbook doesn't mean the car is theirs to sell
How to protect yourself: check first, settle first, never pay on a promise

Read guide → · Related: Can I check if a used car has outstanding finance?

How to use these guides with a free check

Enter the registration to see the full MOT history, mileage timeline and AI condition score for free.
Use the clocked car guide against the mileage timeline before you travel to see the car.
If the car looks worth pursuing, a full history report (£9.99, one-off) runs the write-off, finance, stolen and mileage-discrepancy checks the guides describe.
Take the guide's checklist with you to the viewing.