A write-off category is the label an insurer gives a car it has decided not to repair after a claim. Cat S means the car's structure was damaged, such as the chassis or crumple zones. Cat N means the damage was not structural. Both can be repaired and driven again, but the car stays recorded as a write-off for life, which affects its value and its insurance.
What each category means
Since 1 October 2017 insurers use four categories, set by the industry's code of practice for salvage:
| Category | What it means | Can it go back on the road? |
|---|---|---|
| Cat A | Scrap. The whole car must be crushed. | No |
| Cat B | Break. The body must be crushed; some parts can be sold. | No |
| Cat S | Structural damage, repairable. | Yes, once properly repaired |
| Cat N | Non-structural damage, repairable. | Yes |
Cat S and Cat N replaced the old Cat C and Cat D. The old categories were about money: Cat C meant repairs cost more than the car was worth, Cat D meant repairs cost less but the insurer chose not to do them. The new ones are about the damage itself, which tells a buyer more.
Why insurers write off repairable cars
An insurer writes a car off when paying out is cheaper than repairing it, once the cost of parts, labour, a hire car and the car's lower value afterwards are counted. On an older car that can happen after a minor knock, which is why plenty of Cat N cars had little more than a damaged bumper and headlight. Others had flood damage or a deployed airbag. The category alone does not tell you which.
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How much less a write-off is worth
A Cat S or Cat N car is commonly priced well below the same car with a clean history, often quoted at somewhere between 20% and 40% less. That discount stays with the car when you sell it, so a good price today is only a good deal if you pay less than a write-off is worth, not just less than a clean car.
What to ask before you buy one
- What was the damage? Ask for photos of the car before repair. A reputable seller of a repaired write-off often has them.
- Who repaired it? Invoices from a recognised body shop are worth far more than a verbal assurance.
- Were safety systems involved? Airbags, seatbelt pretensioners and sensors must be replaced, not just reset.
- Will your insurer cover it? Get a quote with the history declared before you commit.
- Has it been inspected? On a Cat S car especially, an independent inspection that checks the alignment of the structure is money well spent.
A dealer must tell you if a car is a write-off. A private seller may not know, or may not say.
How to check whether a car is a write-off
The write-off marker is held on the insurance industry's register, not on the free DVLA or DVSA records, so a free check will not show it. Our write-off check is part of the £9.99 full history check and shows the category and the date of loss where they are recorded, along with outstanding finance and stolen markers.
The MOT record can add context. A car with years of clean tests that suddenly shows bodywork or airbag warning advisories may have been repaired after a claim. Our guide to outstanding finance covers the other history check result you need to see before you pay.
Common questions
Is it legal to buy a Cat S or Cat N car?
Yes. Both categories can be repaired and returned to the road. Cat A and Cat B cars must not be driven again.
Can you insure a Cat S or Cat N car?
Most insurers will, but you must tell them the car's history. Some will not cover a Cat S car, and the premium may be higher than for the same car with a clean record.
Is a Cat N car safe?
It can be. Cat N means the damage was not to the car's structure, but it can still have involved brakes, steering, airbags or electrics. Safety depends on the repair, so ask for the invoices and have the car inspected.
What happened to Cat C and Cat D?
They were replaced on 1 October 2017. Cat C and D were based on the cost of repair compared with the car's value; Cat S and N are based on the type of damage. A car written off before October 2017 keeps its old category.
Written by James Parry. Last reviewed 11 November 2026. Contains public sector information licensed under the Open Government Licence v3.0.