Cat A B S N Explained: What UK Car Write-Off Categories Really Mean

Cat A B S N Explained: If you’ve ever checked a vehicle’s history or dealt with an insurance claim, you’ve probably seen labels like Cat S or Cat N. These are official UK write-off categories used when insurers decide a car isn’t financially viable to repair. That doesn’t always mean the vehicle is beyond saving — sometimes it simply costs more to fix than it’s worth.

Once written off, a category is assigned to show how serious the damage was and whether the car is legally allowed back on the road. These details are recorded with organisations such as the Driver and Vehicle Licensing Agency and appear on vehicle history checks, which is why understanding them matters whether you’re buying, selling, or insuring.

What is a car insurance write-off?

A car becomes an insurance write-off when repair costs (or safety concerns) outweigh its market value. Insurers take into account labour, parts, hire cars, and potential risks before making this decision.

Importantly, being written off doesn’t always mean the car is scrap. Some vehicles can be repaired and driven again — it all depends on the category assigned.

The four UK write-off categories explained

There are four current write-off categories: Cat A, Cat B, Cat S, and Cat N. Each reflects a different level of damage and legal outcome.

Category A — total loss

Category A is the most severe classification. These vehicles are considered completely beyond recovery, usually due to extreme damage such as major fires, heavy impacts, or flooding.

Nothing can be reused, including parts. The entire vehicle must be crushed, and it will never return to the road in any form.

Category B — break for parts only

Cat B vehicles are also permanently banned from driving again, but unlike Cat A, some components may be salvaged.

The body shell must be destroyed, but usable parts like engines, wheels, or interior components can sometimes be recovered. You’ll never legally buy a Cat B car to drive, though parts from these vehicles often re-enter the market.

Category S — structural damage, repairable

Previously known as Cat C, Category S means the car has suffered structural damage but can technically be repaired.

This might involve the chassis, crumple zones, or other load-bearing areas. Once properly repaired and made roadworthy, Cat S cars are allowed back on the road. However, the write-off status stays on the vehicle’s history permanently.

Because of this, Cat S cars usually sell for less than similar models with clean records, which can appeal to buyers on a tighter budget.

Category N — non-structural damage

Formerly Cat D, Category N applies when the damage isn’t structural. This often includes body panels, electrics, interior components, or cosmetic issues.

Mechanically, many Cat N cars are perfectly sound. Like Cat S vehicles, they can be repaired and driven again, but the category will always appear on history checks.

Can Cat S and Cat N cars return to the road?

Yes — both categories allow vehicles to be repaired and legally driven again. However, there’s no insurer-backed approval process for repair quality, and no automatic inspection scheme tied to the category itself.

That means buyers must rely on documentation, repair evidence, and independent inspections to judge whether the work has been carried out properly.

Should you buy a previously written-off car?

It depends on what matters most to you.

On the plus side, written-off cars are usually cheaper, many are already repaired, and you may get more car for your money if the original damage was minor.

On the downside, resale values are lower, insurance can sometimes cost more, finance options may be limited, and poor repairs can lead to expensive issues later.

If you’re considering one, it’s smart to run a full vehicle history check, ask for repair invoices and photos, and arrange an independent inspection. A low purchase price doesn’t always mean low ownership costs.

How Rooster helps you check before you buy

With the Rooster app, you can instantly access vehicle history, write-off categories, MOT records, mileage reports, and estimated valuations. This makes it easy to spot Cat S or Cat N markers early and avoid unpleasant surprises.

You can also compare insurance quotes, book MOTs and repairs for up to 50% less, check compliance zones, and even get a cash offer on your car in seconds — all from one place.

Final thoughts

Write-off categories aren’t automatic deal-breakers, but they’re powerful indicators of risk and useful tools when negotiating. Knowing the difference between Cat A, B, S, and N puts you in control whether you’re buying your next car or reviewing your current one.

And with Rooster, all that insight lives right in your pocket.

Ready to check a car? Download the Rooster app to view vehicle history, compare insurance, book services for less, and manage everything car-related in one place.