Short answer: Cat S and Cat N are both insurance write-off categories for cars that can be repaired and put back on the road. Cat S means the car had structural damage, such as to the frame or chassis. Cat N means the damage was non-structural. In both cases an insurer decided not to pay for the repair, so you should treat either label as a reason to ask more questions, not as a verdict on the car in front of you.
Last reviewed: 22 October 2026. General information for buyers in the UK, based on GOV.UK guidance and the insurance industry’s salvage code. It is not legal or insurance advice.
What an insurance write-off category is
When a damaged car is the subject of an insurance claim, the insurer decides whether to repair it or “write it off”. If it is written off, GOV.UK explains that the insurer pays the owner the car’s current value instead of the cost of repairing it, and the car is given a category that sets out what can happen to it next.
The categories come from the insurance industry’s Code of Practice for the Categorisation of Motor Vehicle Salvage, which is coordinated by the Association of British Insurers (ABI). A car is categorised after it has been inspected by an appropriately qualified person. The category records the insurer’s decision about the damage at that time. It does not tell you how well the car was repaired afterwards.
Cat A and Cat B: scrap only
Categories A and B cannot be repaired. According to GOV.UK:
- Category A: the entire vehicle has to be crushed.
- Category B: the body shell has to be crushed, but other parts can be salvaged from it.
A complete Cat A or Cat B car should not be back on the road. If you are offered one as a running car, or the story does not add up, walk away.
Cat S explained
A Cat S car can be repaired after structural damage. GOV.UK says it can be used again if it is repaired to a roadworthy condition. The salvage code describes it as a repairable vehicle that has sustained damage to any part of the structural frame or chassis, which the insurer has decided not to repair.
Structural damage matters because the frame and chassis are what hold the car together in a crash. A good repair can return the car to the road, but the quality of that repair is what you are really buying.
If an owner keeps a Cat S car after a payout, GOV.UK says they must send the complete log book (V5C) to the insurer and apply for a duplicate using form V62, and DVLA will record the vehicle’s category in the log book.
Cat N explained
A Cat N car can be repaired after non-structural damage. Like Cat S, GOV.UK says it can be used again once it is repaired to a roadworthy condition.
“Non-structural” does not mean “cosmetic only”. The salvage code notes that even when the damage is non-structural, safety-critical items such as steering and suspension parts may still need replacing. A Cat N car might have needed a few panels, or it might have needed a lot of mechanical work. Ask what was damaged and what was replaced.
Cat S vs Cat N at a glance
| Cat S | Cat N | |
|---|---|---|
| Type of damage | Structural (frame or chassis) | Non-structural |
| Can it be repaired? | Yes | Yes |
| Can it go back on the road? | Yes, once repaired to a roadworthy condition | Yes, once repaired to a roadworthy condition |
| Who decided it was a write-off? | The insurer | The insurer |
| Most important thing to check | Who repaired the structure, how, and with what evidence | What was damaged, including steering, suspension and safety systems |
Neither category is automatically “safe” or “unsafe”. Two Cat N cars can be very different, and a well-documented Cat S repair can be a better buy than a Cat N car with no paperwork. Judge the car and the evidence, not just the letter.
Old categories: Cat C and Cat D
Before 1 October 2017 the industry used categories A, B, C and D. The ABI replaced C and D with S and N when the updated salvage code came in. The old categories were based mainly on the cost of repair compared with the car’s value. The new ones are based on the type of damage.
Because the basis changed, Cat S is not simply a new name for Cat C, and Cat N is not simply a new name for Cat D. You may still see older cars advertised as Cat C or Cat D from before the change. Ask the same questions you would for Cat S or Cat N.
Buying a Cat S or Cat N car: what to ask
A seller should be able to answer these questions. If they cannot or will not, treat that as an answer in itself.
- What category is it, and when was it written off? Ask for it in writing, especially from a dealer.
- What was the damage? Ask for photos of the car before the repair, if there are any.
- Who carried out the repair? A named garage or body shop with invoices is better than “a friend did it”.
- Which parts were replaced? Look for invoices for the parts, especially for structural, steering, suspension, brakes and airbag or safety systems.
- Has it been independently inspected since the repair? If not, consider paying for an independent inspection yourself before you buy.
- For Cat S: does the V5C show the category? GOV.UK says DVLA records the category in the log book for a Cat S car that an owner keeps after a payout.
- Do the details match? Check the registration, VIN and engine number on the car against the V5C, as GOV.UK advises for any used car.
On the test drive, notice how the car tracks in a straight line, how the steering feels and whether there are warning lights, uneven tyre wear, mismatched paint or uneven panel gaps. Our used car buying checklist covers the viewing in more detail.
Insurance and resale
Insurers take different views on written-off cars. Some will cover a repaired Cat S or Cat N car, and some may ask for more information about the repair. Speak to your insurer before you buy, and tell them the category. You must declare it if asked.
A write-off category also tends to stay with a car’s history. That can affect how easy it is to sell later and what buyers are willing to pay, so factor it into your decision. We do not give figures here, because they vary from car to car.
How to find out a car’s write-off category
- Ask the seller directly, and ask a dealer to put the answer in writing.
- Look at the V5C. For Cat S cars kept by the owner after a payout, GOV.UK says the category is recorded in the log book.
- Use the free GOV.UK checks to confirm the basic details match the advert: the DVLA vehicle enquiry service, the MOT history service and the vehicle recall check. These official services do not replace asking about the write-off history.
- Consider a commercial vehicle history report, which usually includes insurance write-off records. Our car write-off check guide explains what to look for, and our car history check guide and HPI check guide explain what those reports cover.
For the wider picture, see our vehicle check guide.
Frequently asked questions
Is Cat S worse than Cat N?
Cat S means the car had structural damage and Cat N means it did not, so Cat S is usually the more serious category. What matters most is the quality of the repair and the evidence for it. A Cat N car with no paperwork is not automatically a better buy than a properly documented Cat S repair.
Can you insure a Cat S car?
Often, yes, but it depends on the insurer. Some may ask for details of the repair. Check with your insurer before you buy, and always declare the category.
Does a Cat N car need re-registering?
GOV.UK’s guidance on keeping a written-off car only sets out extra log book steps for Cat S (sending the complete V5C to the insurer and applying for a duplicate with form V62). It says an owner can keep the log book if they keep a Cat N car. If you are unsure about a particular car, contact DVLA.
Does Cat N show on the V5C or the MOT history?
GOV.UK only describes DVLA recording the category in the log book for Cat S cars kept by the owner. The MOT history shows test results, mileage and advisories, not insurance write-offs. Ask the seller and check the car’s history instead of relying on either document alone.
Is it worth buying a Cat S car?
It can be, if the repair was done properly, you have evidence for it, an independent inspection is happy with it, your insurer will cover it, and the price reflects the history. If any of those are missing, it is a riskier purchase.
Sources checked 22 October 2026: GOV.UK, Scrapping your vehicle and insurance write-offs: insurance write-offs; GOV.UK, Check a used vehicle you’re buying; Association of British Insurers, Salvage code updated to help keep dangerous vehicles off the road and Code of Practice for the Categorisation of Motor Vehicle Salvage.