Cat A, B, S, N? What UK Car Write-Off Categories Really Mean

A shiny paint job can cover up a dodgy past. Knowing what these write-off codes mean could save you from buying a money pit - or worse, an unsafe car. In this guide, we’ll break it all down in plain English.

What Is a Car Write-Off?

A write-off is when an insurer decides a vehicle is too damaged to justify the cost of repair. That doesn’t always mean the car is undrivable - sometimes the repairs are just more expensive than the car is worth. Once that decision is made, the car is given a write-off category by the insurer.

There are four main write-off categories you’ll see in the UK: Cat A, Cat B, Cat S, and Cat N. These categories were updated in 2017 to focus more on structural safety rather than just the cost of repair.

The Four UK Car Write-Off Categories

Let’s break down what each one means.

Cat A - Scrap Only

This is the worst-case scenario. A Cat A car has suffered extreme damage and must be completely crushed. No parts can legally be salvaged or reused. You’ll never see these on the market - or at least, you shouldn’t. If someone’s trying to sell you a Cat A car, walk away.

Key points:

• Car is beyond repair

• Must be scrapped in full

• No salvageable parts allowed

• Illegal to put back on the road

Cat B - Break for Parts Only

Cat B cars are also heavily damaged, but some parts may be salvageable. The body shell has to be destroyed, but things like the engine, gearbox, or interior can be removed and sold.

Key points:

• Vehicle can’t return to the road

• Only parts can be salvaged

• Often used by breakers and garages

• Still serious damage

If you’re buying parts from a scrap dealer, they may come from a Cat B vehicle. That’s fine, but don’t buy a whole car that’s been given this status - it’s illegal to drive.

Cat S - Structural Damage

Cat S means the car has suffered structural damage - like damage to the chassis or crumple zones. It can legally be repaired and put back on the road, but it must be done properly. After repairs, the car must be re-registered with the DVLA.

Key points:

• Structural damage involved

• Can be repaired and returned to the road

• Must be properly inspected and re-registered

• Could impact resale value and insurance

If you’re looking at a Cat S car, always ask for proof of repairs and get it inspected independently if possible. Even if it looks fine, there could be hidden issues.

Cat N - Non-Structural Damage

Cat N means the damage didn’t affect the car’s structure - it might be cosmetic (scratches, dents), or involve parts like the electrics or brakes. These cars are usually easier and cheaper to repair than Cat S vehicles.

Key points:

• No structural damage

• Could still have mechanical or electrical issues

• Easier to repair

• Still impacts resale and insurance

Cat N cars can be a decent deal if repaired properly. But don’t let the “non-structural” label fool you - there could still be serious issues hiding underneath.

Why It Matters When Buying Used

Write-off cars can seem like bargains. They’re usually much cheaper than similar models with a clean history. But you need to be careful. Here’s why:

• Safety: Was the repair done properly? Poor repairs can be dangerous.

• Insurance: Some insurers won’t cover Cat S or Cat N vehicles, or they’ll charge more.

• Resale value: Even if the car is fine, it’ll be worth less when you go to sell it.

• Finance issues: Many lenders won’t offer car finance on write-offs.

You need to go in with your eyes open. A cheap car isn’t a deal if it breaks down constantly, costs a fortune to insure, or can’t pass an MOT.

How to Check a Car’s Write-Off Status

The best way to check? Run a full car history check before you buy. At TopCarCheck, we pull data from the Motor Insurance Anti-Fraud and Theft Register (MIAFTR) and other trusted sources to show you:

• Whether the car has been written off

• Which category it falls into (Cat A, B, S, or N)

• When the damage happened

• Whether it’s been repaired and re-registered

You’ll also get loads of other useful info, like mileage history, MOT records, stolen vehicle checks, and more. It takes just a minute to check, but it could save you thousands.

Real-World Example: Cat S Nightmare

Imagine this. Jamie spots a slick-looking Audi A3 on Facebook Marketplace for £4,000. Seller says it’s had “a small bump” but has been repaired. No mention of write-off status.

Jamie buys it, only to find out later it’s a Cat S. The repairs were done cheaply, and the chassis wasn’t properly aligned. Insurance is double what he expected. And when he tries to sell it? No one wants it. He’s stuck with a car worth way less than he paid.

A simple history check would’ve flagged it instantly.

Should You Ever Buy a Write-Off?

It depends. If you know what you’re doing, you can find decent value in Cat N or even Cat S cars - especially if you’re handy with repairs or know a trusted mechanic.

But always:

• Get a full car history check

• Ask for detailed repair records

• Get an independent inspection

• Tell your insurer upfront

Avoid Cat A or Cat B cars completely - they shouldn’t even be on the road.

What About Dealers?

Even if you’re buying from a dealership, don’t assume the car is clean. Dealers are legally required to tell you if a car is a write-off - but not all of them do.

Some hide it in the fine print or use vague wording like “previously repaired”. That’s why doing your own car history check is essential, no matter who you’re buying from.

Key Takeaways

• Cat A and Cat B cars should never be driven - they’re either scrapped or broken for parts.

• Cat S means structural damage - needs solid repairs and DVLA re-registration.

• Cat N is non-structural damage - still check for hidden issues.

• Always do a vehicle history check to reveal write-off status.

• Don’t buy blind. Ask questions, get proof, and inspect the car.

Ready to Check a Car?

Before you put your cash down, run a full vehicle check with TopCarCheck. It’s fast, affordable, and packed with info that could save you from a costly mistake.

You wouldn’t buy a house without checking for damp. Don’t buy a car without checking its past.

Start your car check now and buy smarter.