The difference between Cat N and Cat S is where the damage was. Cat N means non-structural damage, such as bodywork or electrics. Cat S means damage to the structural frame or chassis. Both are repairable insurance write-offs, but Cat S carries more risk, more paperwork and usually a bigger price discount.
- Cat N is non-structural damage. Cat S is structural damage to the frame or chassis
- Both can legally return to the road once repaired to a roadworthy condition
- Cat S has an extra DVLA step: the owner applies for a duplicate V5C so the category is recorded
- Repair quality matters more than the letter on either category
- Cat N is usually the lower-risk choice, but a poor Cat N repair can still be a bad buy
- A write-off check by reg shows the category and date before you view the car
Cat N vs Cat S at a glance
| Cat N | Cat S | |
|---|---|---|
| Meaning | Repairable, non-structural damage | Repairable, structural damage |
| Typical damage | Bodywork, bumpers, electrics, minor mechanical | Chassis legs, pillars, sills, floor, subframes |
| Can it go back on the road? | Yes, once repaired to a roadworthy condition | Yes, once repaired to a roadworthy condition |
| V5C step | Owner keeps the log book | Owner applies for a duplicate V5C (form V62) so DVLA records the category |
| Main risk | Hidden electrical, airbag or cosmetic repair problems | Hidden structural weakness and poor repair quality |
| Price and insurance | Usually easier than Cat S | Usually harder and cheaper to buy |
Sources: GOV.UK, insurance write-offs and the ABI salvage code.
What Cat N means
Cat N is an insurance write-off category for cars with non-structural damage. The insurer decided the repair would cost too much compared with the car's value, but the structure of the car was not damaged. GOV.UK describes it as a vehicle that "can be repaired following non-structural damage" and can be used again once it is repaired to a roadworthy condition.
Typical Cat N cars have had a hard knock to a bumper, wing or door, an electrical fault, or water damage that did not reach the structure. On modern cars a repair bill can climb quickly because of sensors, cameras and airbags, so a car that looks nearly fine can still be written off.
For more on buying one, read Is a Cat N Car Worth Buying?.
What Cat S means
Cat S is for cars with damage to the structural frame or chassis. The ABI's Code of Practice for the Categorisation of Motorised Vehicle Salvage is what insurers use to decide. Load-bearing parts such as chassis legs, the front bulkhead, pillars, inner sills and subframes count as structural. Bolt-on panels such as bonnets, bumpers and wings do not.
Cat S cars can be repaired and used again, but the repair is a bigger job. A good one is measured against the manufacturer's reference points and uses the right parts and joining methods. A poor one can look the same from the outside. Our Category S guide covers how a proper repair is done and what to ask for.
Where did Cat N and Cat S come from?
The ABI revised the categories in October 2017. Cat S and Cat N replaced the old Cat C and Cat D. If you see an older car described as Cat C or Cat D, it was written off before that change. Cat A and Cat B remain for cars that cannot be repaired. Our write-off categories guide compares all four.
Which is safer?
Cat N is usually the lower-risk category because the structure was not damaged. That is not a guarantee. A Cat N car can still have a poor repair, a partly replaced airbag system or lingering water damage. A well-documented Cat S repair done by a good bodyshop can be sound. A badly done one cannot be fixed by paperwork.
Safety comes down to evidence:
- Ask for the repair invoices and photographs
- For Cat S, ask for an engineer's report and any measurement printout
- Check that any airbag that deployed was replaced, not just reset. A lit airbag warning light is an MOT fail
- Commission an independent inspection before you pay
An MOT does not settle the question. It tests roadworthiness against a set list. It does not check how a bodywork repair was done or whether the airbag system was fully replaced. For structural repairs, the MOT inspection manual concentrates on load-bearing parts that testable items are mounted on, and on the structure within 30cm of those mountings. It is not an alignment check.
Paperwork and the DVLA
The paperwork differs. GOV.UK says that to keep a Cat S vehicle after a write-off, the owner sends the complete V5C to the insurer and applies for a free duplicate using form V62, after which DVLA records the category in the log book. GOV.UK's page for Cat N does not describe that extra step.
Whichever category it is, the history stays on the record. A history check will show the category and date, so do not rely on the advert to mention it.
Insurance
You should always tell your insurer about a write-off history, and you should ask before you buy. Some insurers will not quote for write-off cars, and those that do may charge more. Cat S tends to be harder to insure than Cat N. We cover the detail in Can You Insure a Cat S Car?.
Get quotes using the actual registration before you hand over money. The price of cover can change what a good deal looks like.
Price and resale
Both categories sell for less than a comparable car with a clean history. Cat S usually carries the larger discount because buyers see more risk. The size of the discount varies by model, age, damage and repair quality, so compare against similar clean cars and similar write-offs for the same model rather than relying on a rule of thumb.
Remember the marker is permanent. When you sell, you will pass the same history and the same discount on to the next buyer. Finance providers and some dealers may also treat write-off cars differently, which makes them harder to sell.
Which should you choose?
- Choose Cat N if you want the lower-risk route into a write-off car, the repair is documented and the price reflects the history
- Consider Cat S only if the paperwork is strong, an independent engineer has checked the car, you have insurance quotes in hand and the discount is clear
- Walk away from either if the seller has no evidence of the repair, will not let you arrange an inspection, or is vague about what was damaged
If you are a first-time buyer or this will be your only car, a clean-history car is simpler.
How to check which category a car has
The category is held on the vehicle's history record, not on the number plate. The V5C may show it for Cat S, but sellers can omit it from adverts and paperwork can be lost.
The free MOT history will not show a write-off marker. GOV.UK's consumer guide to buying repaired written-off vehicles says a private history check will tell you if a vehicle has been stolen, has outstanding finance, has a mileage discrepancy or has previously been written off.
A write-off check from £9.99 returns the category and date, and you can go straight to a Cat N check or a Cat S check. Do it before you travel to view.
Frequently asked questions
Is Cat N or Cat S worse?
Cat S is generally the more serious category because it involves structural damage. Cat N is non-structural. Repair quality matters for both.
Can a Cat S car be repaired properly?
Yes, by a competent bodyshop using the manufacturer's repair data and correct parts, ideally with an independent inspection afterwards.
Can you drive a Cat N or Cat S car?
Yes, once it has been repaired to a roadworthy condition. Cat A and Cat B cars cannot be put back on the road.
Is Cat N cheaper than Cat S?
Usually not. Cat S tends to sell for a larger discount, because it carries more risk.
Does a Cat N or Cat S car have to pass an MOT?
It takes the normal MOT when one is due. There is no separate structural re-test.
How do I check which category a car has?
Use a write-off check with the registration number. The free MOT history does not show it.