What Are Vehicle Write-Off Categories?
Car Owl
Published in English •
Summary
- UK insurers sort write-offs into four categories: A, B, S and N, based on how badly a car was damaged.
- Cat A and Cat B cars can never legally return to the road. Cat S and Cat N can, if repaired properly.
- A repaired Cat S or Cat N car can be a genuine bargain, but only with proof of a safe, professional repair.
- Always confirm a car's category with a car history check before you buy.
A written-off car is not always a car to avoid. Insurers write off vehicles for all sorts of reasons, and some are lightly damaged. The key is knowing which category a car falls into, because that changes everything about its safety, value and legality.
This guide explains all four UK write-off categories in plain English. You will learn what each one means, which cars are safe to consider, and how to check a car's status before you part with any money.
What Are Write-Off Categories?
When an insurer decides a car is not worth repairing, it records it as a write-off. It then assigns a category to show how serious the damage was. The current UK system uses four codes.
| Category | Damage | Can it return to the road? |
|---|---|---|
| Cat A | Severe, scrap only | No, must be crushed whole |
| Cat B | Extensive, body destroyed | No, but parts can be reused |
| Cat S | Structural, repairable | Yes, after a proper repair |
| Cat N | Non-structural | Yes, after a proper repair |
Cat S and Cat N replaced the older Cat C and Cat D codes in 2017. You may still see the old codes on much older records.
Category A: Scrap Only
Category A is the most severe. These cars are so badly damaged that they must be crushed completely. Not even the parts can be saved.
Cat A usually follows a fire or a catastrophic crash. A Cat A car must never appear for sale as a runner. If one does, walk away and report it, because putting one back on the road is illegal and dangerous.
Category B: Body Destroyed, Parts Salvageable
A Category B car cannot return to the road either. The body shell must be crushed. However, undamaged parts like the engine, gearbox or seats can be removed and reused.
Cat B cars only make sense for a breaker or someone rebuilding a similar model with salvaged parts. As a car to drive, it is a non-starter.
Category S: Structural but Repairable
Category S means the car suffered structural damage. Its chassis or frame, the skeleton that keeps you safe in a crash, took a hit. The good news is it can be repaired and legally driven again.
The risk is a poor repair. Structural work must be done correctly, or the car may not protect you in another accident. If you are looking at a Cat S car, get documented proof of the repair and an independent inspection. Read our full Category S guide for what to check.
Category N: Non-Structural Damage
Category N cars have no structural damage. The frame is sound. The problem is elsewhere, such as bodywork, electrics, lights or trim.
Cat N can be the best value of all the categories. But "non-structural" still covers a wide range, including faults like brakes or steering, so it is not automatically minor. Our Category N guide explains exactly what to look for.
Should You Buy a Written-Off Car?
It depends entirely on the category and the repair. Here is the honest picture.
- Cat A and Cat B: Never as a car to drive. They are not roadworthy, full stop.
- Cat S: Possible, but only with proof of a safe structural repair.
- Cat N: Often good value, once you know the fault was minor and well fixed.
Any written-off car should sell for less than an equivalent clean car, usually 20% to 40% less. If the discount is small, the risk is not worth it.
Remember two extra catches. Some insurers charge more, or refuse cover, on written-off cars. And resale is harder, so you take another hit when you come to sell.
How to Check a Car's Write-Off Status
Never rely on a seller's word alone. Confirm the record yourself.
- Take the car's registration number from the listing or the plate.
- Run a full history check, which searches insurance write-off records.
- Read the result carefully: the category, the date, and the insurer where shown.
- If the car is a repaired Cat S or N, ask for repair invoices and photos.
For a deeper walkthrough, see our main car write-off check guide.
Common Questions
Is it legal to sell a written-off car?
Yes, for Cat S and Cat N cars, as long as the seller declares the category. Selling one without disclosing its history is against the law.
What were Cat C and Cat D?
They are the old codes, replaced in 2017. Cat C roughly maps to Cat S, and Cat D roughly maps to Cat N.
Will a write-off always show on a check?
A recorded write-off will show on a full history check. This is why a check matters, as sellers do not always mention it.
Does a write-off marker ever get removed?
No. Once a car is recorded in a write-off category, that marker stays on its record permanently. Even a beautifully repaired Cat S or Cat N car keeps its history, which is why it is always worth less than a car with a clean record.
Can I insure a repaired Cat S or Cat N car?
Usually yes, but not with every insurer, and some charge more. Always get a quote before you buy so there are no surprises. Our guide on insuring a written-off car explains what to expect.
Write-off categories are simple once you know the code. Cat A and B are off the table. Cat S and N can be smart buys with the right proof. Before you commit, run a car history check to confirm the category and buy with your eyes open.