What is a Cat C car?

Exactly what is a Cat C, Cat N or Cat S car? Here’s our guide to these categories of insurance write-off and repair

By BuyaCar team November 20, 2023

If you’ve ever come across a car for sale that seems suspiciously cheaper than most other equivalent models with the same age and mileage, it’s likely it could have previously been written off by an insurance company. While they could seem like a great deal, these cars can represent a risk to the buyer.

After an accident, if an insurer considers the cost of repair to be greater than the value of the car itself, or the car cannot be repaired safely, they will write the vehicle off. However, after this happens, it gets categorised according to the level of damage, meaning it may or may not eventually be put back on the road.

But, what does Cat C mean? Category C (often shortened to ‘Cat C’) means the insurer has deemed the cost of repair to exceed the value of the vehicle. In these cases, the car isn’t necessarily considered completely unroadworthy. A Cat C car can be safe to drive as long as it’s repaired safely and properly.

The problem is, it can be hard to ascertain what type of repairs have been done and how well they were carried out, and insuring a cat C car can be more expensive than one with a clean history.

However, the new categorisation system introduced in 2017 can be a source of confusion. A car that would have previously been classified as a Cat C could be down as a Cat N - this depends on whether or not the car sustained any structural damage before it was repaired.

The new write-off categories introduced on 1 October 2017 are as follows:

Category A: Car may not be repaired, and must be crushed.
Category B: Car may have its usable parts recycled, but it also must be crushed.
Category N: A write-off that has not sustained any damage to its structure, and which may be repaired and safely returned to the road.
Category S: Car that has suffered structural damage but which is repairable.

So while newly written-off cars are no longer classified as Category C, some cars assessed under the old system (prior to 1 October 2017) will pop up for sale. While these may well have been fully repaired and can now be considered safe to drive, it can be hard to tell how competently these cars have been repaired. As a result, you should be cautious about any vehicle that’s classified as Cat C.

All the cars we sell on BuyaCar will have their histories checked prior to being listed on the site, so you can be sure there will be no unwanted surprises attached to any of our used cars. We also do not list previously written-off cars. Read on for more details on what Cat C means, or click on the button below to start your search for a quality-assured used car.

Car write-off categories

Some write-offs are completely unrecognisable as cars. Others might have minor damage to an expensive part, which means that it’s not economical for an insurer to repair them, but may be cost-effective for a garage to do so with second-hand components.

Between 2007 and September 2017, the insurance industry used four categories of write-offs, from A (the worst) to D (the least serious). If you find a used car that has previously been written off, then it may have been graded under this system.

All write-offs that fell into these categories were recorded on the motor insurance fraud and theft register (MIAFTR). The category a car falls into was decided by the insurer’s inspecting staff or an independent engineer chosen by them. It was not decided by an outside party.

Category A and B cars are too damaged to be repaired and must be scrapped. Cars that fall into Category C are often referred to as ‘Cat C cars’. BuyaCar does not sell cars that have previously been written off.

What is the equivalent of Cat C under the new category system?

Before 2017, whether a car fell into the insurance write-off categories of Cat C and Cat D depended on whether or not the cost of repairs exceeded the value of the car – if the car was deemed more expensive to repair than it was worth, it would be a Cat C write-off. Under the new system, the key criterion is whether or not a car has suffered structural damage. If it has not, it is classed as a Cat N. If it has suffered structural damage, it is classed as a Cat S.

As a result, a car placed in Cat C under the old system could be a Cat N under the new one if it has no structural damage, or a Cat S if it has had some sort of structural repair.

What is a Cat C car?

Cat C cars are what insurers call a repairable total loss: the cost of repairing them is greater than the car’s value. That’s unlike a Cat D car, where the cost of repairing the car is less than the vehicle’s pre-accident value. 

All vehicles classed as Cat C have been damaged. Cars could fall into this category if they have been flooded, damaged by fire or been involved in a crash where the airbags deployed.

Under the Code of Practice, Cat C cars aren’t so badly damaged that they can't be made safe, at least by a respected and professional repairer, but the system does not provide any more detail. So on a fairly new car, the damage may be quite extensive with airbags deployed, although it won’t affect the main structure of the car underneath the bodywork.

Old cars may only sustain minor damage before being classified as Cat C write-offs because they are worth less. The cost of supplying, painting and fitting a new door could be more than the value of the entire car.

Why wouldn't an insurer have a Cat C car repaired?

The simple answer is to save dealing with expensive repair work. By not processing the claim, an insurer will save on the cost of a customer’s hire car, on like-for-like replacement parts, manufacturer-approved repairs and even on simply administering the claim.

These are all costs that a competent independent garage or mechanic can avoid if they repair a vehicle – particularly if they use second-hand parts that many insurers don’t consider. This may mean that they can repair a vehicle for a fraction of the price of an insurer.

If fitted correctly, these parts can return a car to its pre-crash condition but there’s no need for Cat C cars to be inspected to prove that they are roadworthy.

The government has also abolished the requirement to check the identity of Cat C cars, to ensure that they aren’t stolen vehicles that have been disguised with the identity of a written-off car.

Is a Cat C car safe to drive?

Because Cat C cars don't require an official safety inspection before being returned to the road, you may not really know how safe the car is until it’s in an accident.

For example, some unscrupulous repairers cut corners by not connecting the airbags or removing the airbag warning light. Replacement adaptive cruise control and automatic emergency brake sensors may not have been recalibrated, which is an expensive process usually carried out by a main dealer.

A previously flooded car could also have issues that appear later on such as structural corrosion, persistent smells in the cabin and electrical problems.

How do you avoid buying a Cat C car?

Approved used cars have undergone history checks to ensure that they have not been written off. Choosing one of these is a straightforward way of avoiding Cat C vehicles.

If you’re buying independently, then a dealer or motor trader is meant to tell you if the car is a write-off. Under the Consumer Protection from Unfair Trading Regulations (2008) they cannot conceal important information. Meanwhile, under the Sale of Goods Act, they must take all reasonable steps to check a vehicle’s history.

There are fewer safeguards in a private sale. A private seller does not have to declare the car is a write-off but they should so do if asked. If they don't and you later discover the car they sold you has been written off, you could issue a county court claim, although you’d have to prove beyond reasonable doubt that they knew about the car’s history.

The risk of unknowingly buying a previously written-off car is one reason why a history check and vehicle inspection are recommended for private buyers.

Should I buy a Cat C car?

A Cat C car costs less than a vehicle that hasn't been damaged - sometimes as much as 25% less. But you have to weigh the saving against the unknown quantity of a car with a crash history that may never be known and whose safety will have a question mark hanging over it.

Because its write-off status is permanent, it will always be a Cat C car, so if you sell it, the vehicle will be worth less than one that's identical apart from the crash history.

How easy is a Cat C car to insure?

The Association of British Insurers (ABI) says most insurance companies will cover a Cat C car but you are likely to pay a higher premium. The insurer will check your car’s history when you make a claim and could invalidate your cover if you did not declare it was a write-off.

Who polices the insurance write-off Code of Practice?

Insurers decide which category a written-off car should fall into. This could create a conflict of interest because they are also the ones who will benefit from a higher sale price if a vehicle is classified into a low category (C or D).