What Cat N and Cat S mean on a used car
An insurer decided the car wasn't worth repairing. That doesn't make it a bad car, but it changes what you should ask and what you should pay.
The short answer
Cat N means the car was written off with damage that didn't affect its structure. Cat S means the structure was damaged. Both can legally be repaired and driven again. Cat A and Cat B can't.
The category tells you what was damaged, not how well it was repaired. Nobody inspects the repair, so the questions you ask the seller matter.
The four categories
When an insurer writes a car off, it puts it in one of four categories.
| Category | What it means | Back on the road? |
|---|---|---|
| Cat A | Can't be repaired. The whole car must be crushed. | No |
| Cat B | Can't be repaired. The body shell must be crushed, but other parts can be reused. | No |
| Cat S | Repairable. The structure was damaged. | Yes, once repaired |
| Cat N | Repairable. The damage wasn't structural. | Yes, once repaired |
Before October 2017 the repairable categories were called Cat C and Cat D, and you'll still see them on older cars. They were based on what the repair would cost, not on the kind of damage, so they don't line up exactly with S and N.
Why a car gets written off
A write-off is a money decision. The insurer works out that repairing the car properly would cost too much compared with what the car is worth, and pays the owner instead. On an older car worth a couple of thousand pounds, a scraped door and a cracked bumper can be enough.
That is why Cat N covers such a wide range. It can mean cosmetic panel damage. It can also mean damage to parts that matter for safety, such as suspension or steering, as long as the car's structure wasn't affected. The letter alone doesn't tell you which.
Is it safe to buy?
It depends entirely on the repair. No authority checks the work before a Cat S or Cat N car goes back on the road. It needs a valid MOT like any other car, and an MOT is a basic safety test, not an inspection of a repair.
- Ask for the repair invoices. A proper repair leaves paperwork that names the parts replaced.
- Ask for photos of the damage before it was fixed. Salvage auctions photograph every car they sell, so photos often exist.
- For a Cat S car, or any repair you can't see evidence for, pay for an independent inspection. Citizens Advice puts the cost at around £120 to £250.
What it does to the price and the insurance
A written-off car usually sells for noticeably less than the same car with a clean history, and it will be worth less when you sell it too. How much less varies with the car and the damage.
You also need to tell your insurer. Some charge more for a Cat S or Cat N car and some won't cover one, so get a quote before you agree to buy.
How to find out
A dealer should tell you about a write-off they know about. With a private seller, ask the question directly and keep the answer in writing, because the car has to match how it was described.
Don't rely on the logbook. A Cat S write-off is recorded on the V5C, but a Cat N one often isn't. The free MOT history won't show a write-off either. Insurers record write-offs on their own register, which a paid history check searches. A Hindsight paid report shows the category, the date and where the car was damaged, and the Full report adds any salvage auction record.
Ask before you travel
- “Has the car ever been written off, or had an insurance claim for damage?”
- “What was damaged, and who repaired it?”
- “Can I see the repair invoices, and any photos from before the repair?”
- “Are you happy for an independent engineer to inspect it?”
Check the car you're looking at
Type the registration from the advert. You'll see every MOT test and the mileage recorded at each one, free.
Where this comes from
Checked on 13 November 2026. This is general information, not legal advice. For help with a dispute, speak to Citizens Advice.