What is a Cat S car?

If you look through many used car adverts, you might come across 'Category S' or 'Cat S' cars, but what are these and should you be wary?

BuyaCar team
Jul 27, 2022

If a car that has been damaged in a crash, flood, or a fire is too expensive to repair - being expected to cost more to repair than it is worth at the time - it may be written off by the insurer. There are four categories of write-off: A, B, S and N. These replaced the old system that included Category D.

A Category S (or Cat S) car is one that has suffered structural damage, but is still repairable. Even if it is repaired, the car’s salvage category remains with the vehicle for life, which reduces its appeal for many drivers and makes it worth less when it comes to sell it on.

A major flaw in the rules is that there is no legal requirement for repaired salvage cars to be inspected and judged safe for the road. For this reason, it’s difficult to know if a written-off Category S car has been properly repaired and is safe to drive, without a full mechanical inspection.

Beyond safety, dealing with Category S cars is risky in several ways. This label could affect the cost of insurance and is likely to reduce the amount you can sell the car for in future. It even reduces your chances of selling the car at all, as many drivers may choose to avoid buying a car that they know has been written off.

This is why BuyaCar does not sell cars that have been written off - whichever category they fall into - and we recommend caution to ensure that no car you're looking to buy is registered as a Category S vehicle, unless you're fully aware of the car's condition and its value once the fact it's a write-off has been factored in.

Why do insurers write off Cat S cars?

Structural damage is very expensive to repair and insurers are always balancing the cost of making repairs, plus other associated expenses including administration and hire car charges that might result from an insurance claim, against the value of the car before the crash.

If the cost of making repairs and covering the subsequent related bills exceeds the value of the car, they’ll pay the policyholder a settlement figure and write off the car.   

Who repairs Cat S cars?

Independent garages and bodyshops with specialist equipment repair Category S cars. They tend to have quite low overheads because the cars cannot be sold for the same prices as those not recorded as write-offs, so they can buy them for a lower price than undamaged cars.

Many garages that repair write-offs are reputable garages but the fact that their work does not, by law, have to be independently inspected, means consumers cannot be entirely confident a repaired Category S write-off is safe for the road.

Can I drive a Cat S car knowing it is safe?

As mentioned above, the absence of any controls on repair standards means you can't be absolutely sure a repaired Category S write-off is safe to drive. The best advice is to get it independently inspected and at the very least, put it through an MoT test at a garage independent of the dealer selling it.

The majority of issues that would make the car unsafe to drive would be identified during an MoT, so you'd hope that anything untoward would be flagged in an MoT.

Could I buy a Cat S car without realising it?

Important information about a car cannot be concealed from you by a dealer - and that’s the law. So check the paperwork thoroughly and if you have any suspicions, check its history with a vehicle information company such as HPI. If you buy from a dealer that follows a car maker’s approved used car scheme they should have done these checks for you.

You’re on much less safe ground when buying privately. The seller must be honest but if they aren't and you take them to court, they could always claim they didn't know the car was a write-off and get off scot-free. To be on the safe side, run an HPI check on the car and this should alert you to any cars that have been registered as write-offs.

We run HPI checks on every car we stock at BuyaCar. Learn more about how BuyaCar works here.

Is a Cat S car cheaper than a non-write-off?

It certainly should be. The stigma of being a write-off hangs around a Category S car like a bad smell, making it difficult to sell. Its price needs to reflect that to justify a potential buyer choosing one over non-written-off alternatives.

But while it may be cheaper to buy, it also has to be priced low to sell when you’re finished with it, so really, you're no better off. In fact, you may be worse off because you have the problem of persuading potential buyers that the car is safe.

Will I have to pay more to insure a Cat S car?

The short answer is yes. Insurance is all about risk, and Category S cars present a higher risk than cars that are guaranteed to be structurally sound. Their previous and present conditions are uncertain, and the car’s market value is unclear if it’s written off a second time.

Most insurers will consider covering a Category S car, but at a much higher price than a car that has not been written off.

Other categories

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, which may be repaired and safely returned to the road.

What is a car’s structure?

The car’s structure is defined by the Association of British Insurers (ABI), one of the organisations behind the salvage code. It also defines the term ‘damage’ as any structural part requiring realignment to its original dimensions or replacement. A car's structure comprises:

  • Fire wall / front bulkhead
  • Front header rail
  • Side cant rail
  • Rear header rail
  • Rear cross member
  • Rear inner wing
  • Rear wheel housing extension
  • B-post (part of the centre pillar)
  • A-post (part of the front pillar)
  • Front upper wing support
  • Front inner wing
  • Front chassis leg /welded cross member
  • Rear chassis leg
  • Sill

Note: some major components - including the steering and suspension - are not classified as structural.


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