Insurance companies use different write-off categories to describe the level of damage when a car is written off, but many drivers aren’t sure what these labels actually mean.
Should you avoid Cat S and Cat N cars? Can you repair and drive them? And what about Cat A or Cat B vehicles?
In this guide, we explain the meaning behind UK car insurance write-off categories and show you how to check if a vehicle has been written off using the registration number.
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Table of contents
What are the insurance write-off categories for cars?
When a vehicle is badly damaged in an accident, insurers assess whether it’s safe or financially viable to repair. To standardise this, insurance assessors assign a write-off category to indicate the severity and type of damage.
Before October 2017, the categories were: Cat A, Cat B, Cat C, and Cat D, with Cat A being the most severe. However, these were replaced following an update by the Association of British Insurers (ABI) to better prioritise vehicle structural integrity over just repair costs.
The current categories used in the UK are: Cat A, Cat B, Cat S, and Cat N.
Cat A cars meaning
Category A represents the most severe write off classification, reserved for vehicles so badly damaged that neither the car nor its individual parts can be salvaged. According to Aviva’s motor insurance guidance, these vehicles must be crushed entirely, with no components—not even the wheels or battery permitted for resale.
Cat A status typically results from catastrophic incidents like severe fires, complete flooding, or high-speed collisions where structural integrity is entirely compromised. The vehicle identification number (VIN) is removed before crushing to prevent fraudulent attempts to transfer the identity to another vehicle. This category exists primarily as a safety measure, ensuring dangerously damaged vehicles never return to UK roads in any form.
Cat B cars meaning
Cat B vehicles have extensive structural damage, and the body shell must be destroyed. According to the Association of British Insurers’ Code of Practice, the vehicle’s body shell must be destroyed, but undamaged components like engines, transmissions, and electrical systems may be removed first.
Cat B cars cannot be repaired or returned to the road under any circumstances. The chassis is permanently destroyed. If you see a Cat B on a vehicle report, it should never be on the road , if it is, it’s likely fraudulent.
Cat S cars meaning
Cat S means the vehicle suffered structural damage to the chassis, frame, or crumple zones , but can legally be repaired and returned to the road. After professional repair, it must be re-registered with the DVLA before being driven again.
Cat S cars can be good value if properly repaired, but the marker stays on the record permanently. Expect resale value to be 20- 40% lower than an equivalent clean-history car, and be aware that some insurers charge higher premiums or refuse cover entirely.
Always get an independent mechanical inspection before buying a Cat S vehicle.
Cat N cars meaning
Category N designates vehicles with non-structural damage that can be repaired and legally returned to the road. According to the ABI’s Code of Practice, Cat N applies when repair costs exceed the vehicle’s pre-accident value but the damage affects only cosmetic or replaceable components rather than structural elements.
Common Cat N damage includes electrical faults, interior fire damage, or body panel replacements. A vehicle might be categorized as Cat N after extensive paintwork, replacement of airbags, or damage to the infotainment system—issues that are expensive to fix but don’t compromise the vehicle’s structural integrity. When conducting a car category check by vin, Cat N vehicles represent the lowest risk among write-off categories since the chassis and frame remain undamaged.
However, Cat N vehicles must still be inspected before purchase to verify proper repairs. While these cars can be roadworthy, they typically sell for 20-40% below market value due to their insurance history marker, which persists even after professional restoration.
Quick rule: Never buy a Cat A or Cat B car. For Cat S or Cat N, always get an independent inspection before paying.
What causes a car to be written off? (Understanding insurance write-off conditions)
Insurers follow a structured process before declaring a total loss. Common causes include:
- Repair costs that exceed the vehicle’s current market value (even by a small margin)
- Structural damage to the chassis or crumple zones (Cat S)
- Airbag deployment, electrical faults, or steering damage that’s expensive to restore (Cat N)
- Fire or flood damage, where safety cannot be guaranteed after repairs
- Theft recovery — if the car was found damaged or stripped after a payout was made
All of these are recorded in insurance and MIAFTR databases and appear on a full vehicle history check.
These are all recorded in the vehicle’s insurance history and made available through our comprehensive Condition/Write-Off Check Report.
Is it worth buying a car with a write-off category?
- If you learn that a vehicle you wish to purchase has been offered a Category S or Category N, you should carefully examine its history before making any payments.
- It is crucial to examine how the damage may have affected the car’s resale value and overall quality. Most of the time, Category S and Category N cars that have been professionally repaired can still be outstanding. Get a car inspection if possible to get an expert assess the car before your purchase to be on the safe side.
- You must back out of the deal, though, if your car category check indicates that the vehicle is classified as either Category A or Category B.
- The car will not be covered by insurance, and you won’t be able to lawfully drive it.
How does a category affect vehicle value?
Depending on your car’s category status, there will be differences in how you sell it and how much it is worth.
A Category S car, for instance, could potentially lose 20-40% of its original value compared to a non-category vehicle of the same year, make, and model, due to the damage it has sustained.
Our detailed 8-point car valuations are included in every comprehensive vehicle report, along with write-off and salvage history, giving you a complete picture of a vehicle’s true worth before you buy.
What differences exist in the selling process for category cars?
A car that is classified as Category S or N must have the write-off category declared. You cannot sell your car privately if it falls under Category A or B, but some parts from Category B vehicles might still be usable.
Authorised Treatment Facilities (ATFs) or scrap yards scrap cars classified as Category A and B.
Know more about Cat S & Cat N category cars with our extensinve guide!
Which car category is legal to sell?
You can sell a Cat N or Cat S car as long as you tell the buyer about its status. You must be clear about this, even if the car has been fixed up to how it was before the accident.
Are category cars harder to sell?
When a vehicle is in an accident and classified as a ‘Cat N’, its desirability among potential buyers decreases. This hesitation leads to a reduction in the car’s market value, making it less appealing than a comparable vehicle that hasn’t been in an accident.
When buying a used car, research is key. Cat N cars may be cheaper, but a history check ensures safety and value.
Car write off checks on CarAnalytics help buyers identify the condition that led to the write-off, along with finance records and stolen vehicle reports, allowing them to buy with confidence.
Frequently asked questions
No, cars with a write-off category like Category A, B, S, or N usually aren’t covered by a manufacturer’s warranty. These are considered salvage vehicles, making the warranty invalid.
Yes, older cars are more likely to be written off for minor damage, simply because their market value is lower—even if repairs are possible.
Insurance companies pay the car’s current market value at the time it’s written off—not what you originally paid. If you have finance on the car, contact your lender to understand what’s still owed.
DVLA doesn’t show write-off info. In the UK, write-off checks aren’t free, services like CarAnalytics, you can find out if a car has been written off from just £4.99.
