TL;DR
Cat S means a car has been written off with structural damage (chassis, frame, crumple zones). Cat N means it was written off with non-structural damage (electrics, panels, mechanical parts). Both can be repaired and driven again, but Cat S cars must be re-registered with the DVLA before returning to the road. Buying either can save you money, but only if the repairs have been done properly and you know exactly what you’re getting into.
If you’re browsing used cars and spot one priced well below market value, there’s a good chance it carries a Cat S or Cat N marker. These insurance write-off categories tell you the car was previously damaged badly enough that an insurer decided it wasn’t worth repairing. That doesn’t necessarily mean the car is dangerous or worthless, but it does mean you need to understand what happened and what was done about it.
The difference between Cat S and Cat N comes down to one thing: whether the damage was structural. Getting this wrong could cost you thousands, or worse, put you in an unsafe vehicle.
What Is a Cat S Car?
Cat S stands for “structural.” A car given this category has suffered damage to its structural frame, chassis, or crumple zones. This is the kind of damage that affects the core skeleton of the vehicle, the parts designed to keep you safe in a crash.
Common examples of Cat S damage include:
- ✓
A bent or twisted chassis after a collision
- ✓
Crumple zones that have collapsed
- ✓
Damage to structural pillars (A, B, or C pillars)
- ✓
A warped subframe or suspension mounting points
Cat S cars can legally be repaired and put back on the road. However, the insurer must submit a Form V23 to the DVLA, which means the car’s V5C (logbook) is cancelled. Before driving a Cat S car again, you need to re-register it with the DVLA and get a new V5C.
What Is a Cat N Car?
Cat N stands for “non-structural.” The car has been written off, but its structural frame is intact. The damage is to other parts of the vehicle: body panels, bumpers, lights, electrics, or mechanical components.
Don’t let “non-structural” fool you into thinking the damage is minor. A Cat N car might have:
- ✓
Serious electrical faults
- ✓
Damaged brakes or steering components
- ✓
Fire or flood damage (if the structure survived)
- ✓
Extensive cosmetic damage across multiple panels
Unlike Cat S, there is no requirement for the insurer to notify the DVLA when a car is categorised as Cat N. This means you won’t always spot it on the V5C. The marker lives in insurance industry databases instead, which is why running a vehicle history check matters.
Cat S vs Cat N: The Key Differences
| Feature | Cat S | Cat N |
|---|---|---|
| Type of damage | Structural (chassis, frame, crumple zones) | Non-structural (panels, electrics, mechanical) |
| Can be repaired? | Yes | Yes |
| Can be driven again? | Yes, after re-registration | Yes, once repaired |
| DVLA notified? | Yes (Form V23 submitted) | No |
| V5C cancelled? | Yes, must be re-registered | No |
| Typical price discount | Larger (often 40%+ below market) | Moderate (often 20-30% below market) |
| Resale difficulty | Harder to sell | Easier than Cat S, but still below clean cars |
| Write-off marker removable? | No, permanent | No, permanent |
Where do these categories come from?
Cat S and Cat N replaced the older Cat C and Cat D categories in October 2017. The change was made by the Association of British Insurers (ABI) to focus on the type of damage rather than just the cost of repair. You can read more about write-off categories on the GOV.UK scrapped and written-off vehicles page.
Should You Buy a Cat S or Cat N Car?
There’s no blanket answer. Both can be sensible purchases in the right circumstances, and both can be expensive mistakes if you skip your due diligence.
When buying a Cat S or Cat N car makes sense
You want a better car for your budget
A Cat N Ford Focus might cost significantly less than a clean example with the same mileage and spec. If the repairs were done properly, you get more car for your money.
You’re mechanically confident
If you can inspect the repair work yourself (or know someone who can), you’re better placed to judge whether the car is safe and worth the money.
You plan to keep the car long-term
Resale value takes the biggest hit. If you’re not planning to sell the car for years, the initial saving matters more than future depreciation.
The damage was cosmetic (Cat N)
Some Cat N cars were written off simply because replacement panels cost more than the car’s value. That’s not a safety concern.
When you should walk away
- ✗
No repair history available. If the seller can’t show you invoices or evidence of what was fixed, you’re buying blind.
- ✗
The price seems too good. A Cat S car at 60% off might mean the repairs were done on the cheap.
- ✗
You can’t get insurance. Some insurers won’t cover Cat S cars, and premiums can be noticeably higher. Check before you commit.
- ✗
The seller doesn’t mention the write-off status. Private sellers are legally required to disclose this. If they didn’t, that’s a red flag about what else they might be hiding.
Insurance for Cat S and Cat N Cars
This is where many buyers get caught out. Not all insurers will cover previously written-off vehicles, and those that do may charge higher premiums. You must declare the write-off status when arranging cover. Hiding it counts as non-disclosure and could invalidate your entire policy.
Cat S cars are generally harder to insure than Cat N. The structural damage history makes insurers nervous about how the car would perform in another collision. Shop around using comparison sites, and get quotes before you agree to buy the car.
The RAC’s guide to insurance write-offs has useful detail on what to expect from insurers.
How to Check if a Car Is Cat S or Cat N
A Cat S marker will usually show on the V5C because the car had to be re-registered. But Cat N is trickier, as there’s no DVLA notification requirement. The marker sits in insurance databases like MIAFTR (the Motor Insurance Anti-Fraud and Theft Register).
Before buying any used car, especially from a private seller, you should:
- ✓
Run a vehicle history check that covers write-off status, outstanding finance, stolen markers, and mileage discrepancies
- ✓
Check the MOT history for free on GOV.UK to see if mileage readings are consistent and whether advisories flag recurring issues
- ✓
Ask for repair invoices and check that a professional body shop carried out the work
- ✓
Get an independent inspection from a qualified engineer, the AA, or the RAC
Don’t buy a write-off blind
A CarVerify check pulls data from the DVLA, DVSA, Police National Computer, Experian, and MIAFTR to reveal write-off history, outstanding finance, stolen status, and more. Backed by a £30,000 data guarantee on finance information.
Can You Remove a Cat S or Cat N Marker?
No. Once an insurer applies a Cat S or Cat N marker, it stays on the vehicle’s record permanently. No amount of repair work will remove it. This is worth understanding before you buy, because it will affect the car’s value for as long as you own it, and for every owner after you.
Be wary of anyone who claims they can “clear” a write-off marker. They can’t, and attempting to conceal it is fraud.
What About Cat A and Cat B?
You’ll sometimes see Cat A and Cat B mentioned alongside Cat S and Cat N. These are the two categories you can’t repair:
Cat A (scrap only)
The entire vehicle must be crushed. No parts can be salvaged. This is reserved for the most severely damaged cars.
Cat B (body shell must be crushed)
The body shell is destroyed, but usable parts (engine, gearbox, electronics) can be stripped and sold. The car itself can never return to the road.
You shouldn’t encounter Cat A or Cat B vehicles for sale as driveable cars. If you do, something has gone seriously wrong. The government’s write-off categories guidance explains the full classification system.
Selling a Cat S or Cat N Car
If you already own a write-off car and want to sell it, honesty is your best policy (and a legal requirement). You must disclose the write-off status to any buyer. If you’re selling through a dealer, they should already know from their own checks.
To get the best price, keep all repair documentation, have a recent MOT pass to show, and consider getting an independent inspection report that you can share with potential buyers. Transparency builds trust and makes negotiations smoother.
For broader guidance on your rights when buying and selling vehicles, Citizens Advice has a helpful section on buying and repairing cars.
Buying a Cat S or Cat N car isn’t inherently risky, but buying one without doing your homework is. Check the history, inspect the repairs, sort out insurance, and go in with your eyes open. The savings can be genuine if you know what you’re looking at.