Car write-off categories explained
RegVerdict guide·6 min read·Reviewed 17 June 2026
What Cat A, B, S and N actually mean, whether the car is safe to buy, and how hard to negotiate.
A car is written off when an insurer decides it is not economical, or not safe, to repair after an accident, fire, flood or theft. The insurer then assigns a salvage category that tells you how serious the damage was. Crucially, a write-off is not always a wreck: two of the four categories can be repaired and legally driven again, and they often appear for sale at tempting prices.
Since October 2017 the UK uses four categories set by the Association of British Insurers: A, B, S and N. Older records may still show the previous scheme (C, D and F). Here is what each one means for a buyer.
Category A: scrap only
Never road legalThe most severe write-off. The whole vehicle, including every part, must be crushed and can never legally return to the road.
- Road legal:
- No, ever
- Structural:
- Yes
- Value:
- Not roadworthy. It has no legal value as a car to drive.
What to do: Walk away. A Category A vehicle must be destroyed; if one is being offered as a runner, something is seriously wrong.
- Why is a Category A vehicle being offered for road use at all?
Category B: break for parts
Never road legalSevere damage. The body shell must be crushed, though some salvaged parts may be reused in other cars. The vehicle itself can never legally return to the road.
- Road legal:
- No, ever
- Structural:
- Yes
- Value:
- Not roadworthy as a whole vehicle; only its parts are salvageable.
What to do: Walk away. A Category B car cannot legally be driven, no matter how good the repair looks.
- Why is a Category B vehicle being sold as roadworthy?
Category S: structural damage
SeriousStructural damage was recorded, to load-bearing parts such as the chassis or crumple zones, and the insurer wrote it off. It can legally return to the road once professionally repaired and re-registered, but the original damage was significant.
- Road legal:
- Yes, after repair
- Structural:
- Yes
- Value:
- Usually worth meaningfully less than a clean example, often 20 to 40% lower, depending on the repair.
What to do: Proceed only with caution. Get documented evidence of a professional structural repair and an independent inspection, and use the category to negotiate hard.
- Who carried out the structural repair, and is there documented evidence?
- Can I have it independently inspected before buying?
- Has it passed an MOT since the repair?
Category N: non-structural damage
CautionNon-structural damage was recorded, typically cosmetic or electrical, though 'non-structural' can still include safety items like lights, airbags or steering. It can legally return to the road after repair.
- Road legal:
- Yes, after repair
- Structural:
- No
- Value:
- Usually worth somewhat less than a clean example, often around 10 to 25% lower.
What to do: Often fine if it was properly repaired, but verify. Check the repair quality (especially any safety items) and use it to negotiate the price.
- What exactly was the damage, and how was it repaired?
- Were any safety items (airbags, brakes, steering) affected?
- Can I see repair invoices, or have it independently inspected?
The older categories (C, D and F)
Vehicles written off before October 2017 use the previous letters. You will still see these on older cars:
- Category C: repairable, but repair cost exceeded the car's value. Treat it like a Category S.
- Category D: lighter damage that was uneconomical to repair at the time. Treat it like a Category N.
- Category F: fire damage. Repair quality is critical, because fire can affect wiring, safety systems and structure in ways that are hard to see.
Is it safe to buy a written-off car?
Category A and B cars must never return to the road, so if one is offered as a runner, walk away. Category S and N cars can be a genuine bargain, but only if you treat the category as a prompt to investigate, not a detail to ignore. The single biggest risk is a hidden or botched repair, especially to safety items like airbags, brakes or steering.
How to check if a car has been written off
The insurance write-off marker is held on industry databases, not on the free gov.uk MOT record, so a basic MOT check will not show it. A vehicle history check reads the write-off status alongside the mileage and MOT history and, when a marker is found, RegVerdict explains the category in clear terms rather than just printing a letter. If you are weighing up a specific model, our reliability data shows how well it tends to hold up at MOT.