# What Do Cat S, Cat N, Cat C and Cat D Mean? Write-Offs Explained

Published 27 September 2026, updated 05 November 2026. CarCheckUp guide: https://carcheckup.co.uk/blog/cat-s-cat-n-cat-c-cat-d-write-offs-explained/

> What the insurance write-off categories mean, how the current Cat A, B, S and N differ from the old Cat C and D, and what to check before buying a repaired write-off.

When an insurer decides a damaged car isn't worth repairing, or can't be repaired safely, it is **written off** and given a category. That category stays on the car's record for life, and it matters a lot if you are buying: it affects safety, insurance and what the car is worth.

Looking for one category? See [what Cat N means](https://carcheckup.co.uk/what-is-a-cat-n-car) and [what Cat S means](https://carcheckup.co.uk/what-is-a-cat-s-car), or check a car with the [write-off check](https://carcheckup.co.uk/written-off-vehicle-check).

## The current categories (since October 2017)

- **Category A – scrap:** the whole car must be crushed. No parts can be reused.
- **Category B – break:** the body shell must be crushed, but some parts can be salvaged. The car must never return to the road.
- **Category S – structural:** the structure or chassis was damaged (for example a bent chassis or crumple zone). It can be professionally repaired and return to the road.
- **Category N – non-structural:** the damage didn't affect the structure (for example cosmetic, electrical or trim damage). It can be repaired and return to the road.

## The old categories: Cat C and Cat D

Cars written off before October 2017 may show the old categories. These were based on repair *cost*, not the type of damage:

- **Category C:** the repair would have cost more than the car was worth.
- **Category D:** the repair would have cost less than the car was worth, but the insurer chose not to repair it.

So an old Cat C car may have had minor damage on a low-value car, while a Cat D car could have had serious damage. Treat both with the same care as Cat S and Cat N.

## Is it safe to buy a Cat S or Cat N car?

It can be, if the repair was done properly. Many repaired write-offs are sound cars sold at a lower price. The risk is a cheap, hidden repair. Before you buy:

- Ask for photos of the damage and invoices for the repair, ideally from a recognised body shop.
- Pay for an independent inspection, especially on a Cat S car. Ask the inspector to check panel gaps, paint depth, welding and airbags.
- Check the price reflects the write-off. A repaired write-off is usually worth noticeably less than the same car without one, and it will be when you sell it too.
- Get an insurance quote first. Some insurers charge more for write-offs and a few won't cover them.

## You must tell your insurer

If you buy a repaired write-off, tell your insurer about the category. If you don't, a claim could be refused because the policy was based on wrong information.

## How to find out if a car is a write-off

A seller should tell you, but not all do, and some don't know. A [written-off car check](https://carcheckup.co.uk/written-off-vehicle-check) shows any insurance write-off record, its category and the date. It's part of every [full history report](https://carcheckup.co.uk/sample-car-history-report), alongside finance, theft and mileage. Ask the seller too whether the car went through a salvage auction: one that did was usually damaged, even if the record is old. A car recorded as [scrapped](https://carcheckup.co.uk/blog/scrapped-cars-and-certificates-of-destruction-explained/) is different again: it should never be for sale at all.

## Key points

- Cat A and B cars must never return to the road. Cat S and N cars can, once repaired.
- Old Cat C and D categories were about cost, not how bad the damage was.
- Get repair evidence, an inspection and an insurance quote before buying a repaired write-off. Read more on [what a car history check covers](https://carcheckup.co.uk/blog/what-is-a-car-history-check/).

Many buyers search for a **written off check** or a **car damage history check** when they want to know this. Our [write-off check](https://carcheckup.co.uk/written-off-vehicle-check) shows whether an insurer has recorded the car as Cat S, N, C or D, with the loss date and cause of damage where supplied, so you can **check the damage history** before you agree a price.