Cat S and Cat N: what a write-off category means

For anyone looking at a used car sold as Cat S or Cat N, or whose own car has just been written off: what the four write-off categories mean, which cars can go back on the road, and what to check before you buy one.

The categories

What do Cat S and Cat N mean?

When your car is written off, your insurer pays you its current value instead of the cost of repairing it.1

Insurers then put it in one of four categories, using an industry-wide code of practice that all the ABI's member motor insurers support.2

The four categories

CategoryCan it be repaired?Can it go back on the road?
ANo. The whole vehicle has to be crushed.1No1
BNo. The body shell has to be crushed, but other parts can be salvaged.1
SYes. It has damage to some part of its structural frame or chassis.3Yes, once it's repaired to a roadworthy condition1
NYes. Its structural frame and chassis aren't damaged.3

Who decides

Who decides a car's category?

Typically, a car is written off when repairing it would cost more than it's worth.2 The category is decided by an assessor trained in vehicle repair, whom the code calls an Appropriately Qualified Person.3

The code is written by the Association of British Insurers (ABI), the insurance industry's trade body. It's a set of guidelines, not the law.3

Structural or not

What counts as structural damage?

Under the code, damage is structural if any structural part needs repairing, realigning to its original dimensions or replacing, but not if the repair is cosmetic and the structure needs no realigning.3

The lists below use the code's own names for the parts.

  • Structural (Cat S). The parts the code lists include the front and rear chassis legs, the inner A and B pillar reinforcements, the inner sill reinforcement and the fire wall or front bulkhead.3
  • Non-structural (Cat N). The parts it lists include the front and rear bumpers, the bonnet, the front wings, the door skins, the roof panel and the boot lid or tailgate.3
  • Electric cars. In some, the battery provides the floor structure. If that battery is damaged, the car must be Cat S.3
  • Non-structural doesn't mean minor. The code says a Cat N car may still have safety critical items that need replacing.3

Finding out

How can you tell a car's category?

  • A vehicle history check. Under the code, every categorised car must be recorded on the Motor Insurance Anti-Fraud Theft Register, and that record is passed to companies that provide vehicle checks to the public.3
  • The log book, for Cat S. DVLA reissues a Cat S car's log book with a note of its status.3
  • A Cat N car's log book is reissued with no note of its category.3 So for Cat N, the log book alone won't tell you.

Is a written-off car worth less?

The Financial Ombudsman Service says a car that has been written off before can put off buyers, no matter how well it's been repaired, and that insurers are likely to lower its valuation.4

That matters if the car is ever written off again, or stolen and not recovered. If you knew, or should have known, you were buying a repaired write-off, the Ombudsman may decide it's fair for your insurer to take off the difference in value. If it thinks you reasonably didn't know the car's history, it's likely to tell your insurer to pay you the full market value.4

In six complaints the Ombudsman decided from 2022 to 2026, insurers took between 10% and 32.30% off a car's value because it had been written off before. Three of the six insurers kept a 20% deduction; one lowered its 20% to 10%. In 2024 the Ombudsman said it's fair for an insurer to take money off for a past write-off, provided it can show the car would have been worth less, and by how much.6

CaseTaken offThe Ombudsman's decision
2022, Cat N20%, lowered to 10%Fair and reasonable at 10%5
2024, Cat S20%Fair, though the owner said he hadn't known: similar written-off cars had lost around 20%6
2025, Cat S20%Not shown to be fair for that car's age and mileage7
2025, Cat S20%Not unreasonable: a similar Cat S car was advertised for just under 25% less8
2025, Cat N32.30%Fair: based on research across 27 similar Cat N cars9
2026, Cat N17.6%Fair: the insurer showed how it had considered the car's make, model and condition10

Each decision was about one car, so none of them is a figure for any other car.

Should you buy a Cat S or Cat N car?

It can go back on the road once it's repaired to a roadworthy condition. But a past write-off can lower what it's worth, to buyers and to insurers, so know its category before you agree a price.

Before you buy a Cat S or Cat N car

Before you buy

Do the usual used-car checks too: see Before you buy a used car.

Roadworthy checks tax, MOT and MOT history from scanning or entering a number plate.

Check a car with Roadworthy

Free, for Android.

Your own car

If your own car has been written off

  • Tell DVLA it's been written off. You can be fined £1,000 if you don't.1
  • You can keep a Cat S or Cat N car. Your insurer pays you out and sells the car back to you.1
  • To keep a Cat S car, send the complete log book to your insurer and apply for a free duplicate on form V62. DVLA records the category in it.1
  • To keep a Cat N car, you can keep its log book.1

Sources

  1. GOV.UK, Scrapping your vehicle and insurance write-offs: Insurance write-offs
  2. Association of British Insurers, Written off or total loss vehicles
  3. Association of British Insurers, Code of Practice for the Categorisation of Motorised Vehicle Salvage, 28 May 2025
  4. Financial Ombudsman Service, Motor valuations and write-offs
  5. Financial Ombudsman Service, decision DRN-3714619, 2022
  6. Financial Ombudsman Service, decision DRN-4872814, 2024
  7. Financial Ombudsman Service, decision DRN-5206901, 2025
  8. Financial Ombudsman Service, decision DRN-5277832, 2025
  9. Financial Ombudsman Service, decision DRN-5834767, 2025
  10. Financial Ombudsman Service, decision DRN-6109884, 2026

First published 14 October 2026. Last updated 14 October 2026. General information, not legal advice.