Category A, B, S and N Cars explained

Before October 2017, you’ll have no doubt seen used cars on the market referred to as ‘Category C’ or ‘Category D’ cars; often shortened to ‘Cat C and Cat D’. They’d often be for sale at bargain prices, and made for a tempting proposition when glancing through the classifieds.

That’s because these are cars that had been ‘written-off’ at some point in their life, deemed to be damaged beyond ‘economic’ repair by insurers, but had since been fixed up and made roadworthy again.

But now, taking into account the increasing mechanical and technological complexity of cars, the ABI have overhauled this rating system. Written-off cars are today assigned to car damage categories A, B, S and N.

In this guide, we’ll tell you everything you need to know about write-offs, explain what these new categories mean, and outline what the implications are for you.

Write-offs explained

If car is damaged, be it as a result of a crash, fire, flood or vandalism, any fully comprehensive motor insurance policy would usually pay out for repairs. But in circumstances where the repairs required are deemed to exceed the value of the car itself, the insurance company will pay out most of the car’s value to you and then take ownership; in essence they ‘buy you out’. Based on the nature of the damage, the policy provider will then assign the car a write-off category.

But there’s a catch. The cost of any potential repairs are calculated on the assumption that all work will be carried out at official workshops with new and approved parts. This is because insurers have a duty to return the car to its previous condition, and are bound by strict guidelines.

It could also be the case that, under your policy, repair costs don’t actually need to surpass the car’s value for it to be deemed a write-off. Instead, there may be a repair-to-value ratio, where repair costs only need exceed a certain percentage of your car’s value for it to be a write off.

What this means is that many written-off vehicles in the two least severe categories (formerly C and D, now S and N) make it back to the road after repairs. That’s because repairing and reselling them makes economic sense, after all. Private individuals and salvage companies aren’t bound by the same regulation as insurers. If the damage isn’t too severe, insurance companies sell the car back to the original owner, or on to a third party via a salvage company.

Of course, this only applies to Cat S and Cat N cars. Cat A and Cat B cars are deemed to be damaged beyond repair, and will end up having only a few parts re-used at most, before they go to scrap.

Why the changes?

Under the previous system, the emphasis was placed primarily on the value of damage. This meant that whether a car received a classification of ‘Cat C damage’ or ‘Cat D damage’ relied entirely on cost, and the two categories told any potential buyer or future owner little about the nature of the damage.

Under the new system, the state of any vehicle that could or has returned to the road is better clarified. Structural integrity has great implications for safety, so in splitting the two ‘repairable’ categories by whether or not they’ve been structurally compromised places this at the forefront. Ultimately, the new categories give buyers a greater understanding of what they’re taking on.

Category A


These are cars that have been damaged so severely that no single part should be considered reliable. They will never be allowed back on the roads, and even parts that could appear to be salvageable must be crushed and destroyed.

Scenarios in which a car may be assigned as a Cat A write-off include catastrophic fire damage, or an extremely severe crush incident.

Category B


Cat B write-offs will have been very seriously damaged. In almost all cases, the body shell should be crushed and destroyed, along with any parts that show clear damage. However, unlike Category A write-offs, any parts deemed to be undamaged can be salvaged and reused in other road-going vehicles.

Cars damaged in high-speed or head-on collisions are likely to be placed in Cat B; where by severe damage to a particular section of the vehicle renders it beyond repair, but various parts may stand untouched and could be reused.

Category S

“Structurally damaged repairable”

Formerly ‘Cat C’, this was the more severe of the two ‘repairable’ categories. A Category S car now represents a vehicle that’s received structural damage.

Cat S/Former Cat C car damage is likely to cover serious collisions at low, or perhaps even moderate speeds. A Cat S car’s body will have clearly been compromised and it’s unlikely the vehicle will be safe to drive at all until repairs are made.

Category N

“Non-structurally damaged repairable”

Previously known as ‘Cat D’, the new Cat N represents the least severely damaged write-offs. Under the new classification, cars in this group will not have received any structural damage. That’s not to say any issues will be purely cosmetic; non-structural faults could include brakes and steering for example.

Ultimately, even though there’s a wide spectrum of reasons a Cat N car could have been written-off, you’ll have confidence in knowing no issues are structural. This tells you repairs shouldn’t be too problematic, and that the car could be as safe as ever once these are made.

Cars placed in Cat N range from those that have received dents and scrapes along their bodywork, to vehicles which may have had their electrical systems damaged by floodwater. Any collisions that Category N cars have been involved in are sure to be minor; most likely low-speed bumps and shunts.

Buying written-off cars

If you choose a written-off car, you’re likely to buy it with the necessary repairs having been made, but some are sold in their still-damaged state. The buyer will make this explicitly clear, so the choice is yours. If you buy a damaged car, you’ll need to arrange the repairs yourself.

Either way, there’s no denying there are some great deals on written-off cars. But there are some drawbacks. The value of these vehicles will remain persistently low for their entire life, and there could well be unseen damage that you encounter problems with further down the line. Depending on how and where they’ve been serviced, there’s no guarantee the work has been done to a high standard. 

Ultimately, whether you take the risk is up to you. But you should always approach any written-off vehicle with an element of caution.

What if I suspect a car has been written-off, but it hasn’t received a classification?

Unfortunately, this is something you could come across when buying a used car from a private individual or garage. Insurance write-off damage significantly reduces the value of the car for the entirety of its usable life, so some sellers might try and hide this in order to get a better price.

If at all you suspect a car has been involved in a serious accident and has received repair work, but hasn’t been listed as Cat S or Cat N, rule it out. At least until you can perform a full HPI check – any write offs are listed on the car’s logbook, so you’ll receive accurate information you can trust.

If you are sold a written-off car without being informed of its previous damage, this is a violation of the Consumer Rights Act. You’re free to return it for a full-refund within 30 days purchase, otherwise you’ll need to take the seller to court under the Consumer Rights Act if they refuse to take it back outside of this.

When you buy your used car from approved dealerships like Inchcape, you can be confident we’ve checked everything over.