What is a Cat A, Cat B, Cat S or Cat N write-off?

There are four categories for the classification of written-off cars. We explain Cat A, Cat B, Cat N and Cat S, and reveal which scrapped cars could be a bargain...

Crashed BMW 5 series Touring

If you're browsing the classifieds for a used car, you might notice the ones that are most temptingly priced are often labelled Cat N. But what does this mean, and is there a catch that means these models should be avoided?

Well, Cat N is one of four levels of damage used by the insurance industry to describe cars that have been involved in accidents; the others are Cat A, Cat B and Cat S.

The Association of British Insurers (ABI), which regulates the salvage code for car insurers, says these codes “reflect the increasing complexity of newer vehicles, which can make it harder for damaged cars to be safely repaired”.

Below, we explain A, B, S and N categories in detail. Unlike the previous system, which only had two categories, the four-category system focuses on the condition of the car, rather than how much it would cost insurers to repair it.

Category A, or ‘Scrap’ cars

These are the most badly damaged cars around, and cannot be repaired. They can only be crushed for scrap.

Category B, or ‘Break’ cars

These cars are still very badly damaged, and are again beyond repair. However, their parts can be salvaged and recycled if they're still in a repairable condition.

Category S, or ‘Structural’ cars

Cars in this category have sustained damage to their structural frame, but can be repaired and re-sold. If you’re thinking of buying a Category S car, make sure that a qualified mechanic has inspected it.

Category N, or ‘Non-structural’ cars

This is the equivalent of the previous Cat D category, and identifies a car that's been involved in an accident, but has not suffered damage to its structural frame. It's important to note that this code states that, although the core safety structures of these cars haven't been damaged, there may still be safety-critical parts – such as suspension or steering components – that need replacing.

Crashed Porsche 997 GT3 RS

Should I buy a car that's been written off?

On the surface, buying a Category N car can look tempting, given that these often have attention-grabbing prices, but it's important to research the history of any car you're thinking of buying. Here are our top tips if you're interested in buying a car that's been written off.

1. Buy the car from a dealer instead of a private seller

If you buy any car, including a Cat D vehicle, from a dealer then you have more consumer rights should anything go wrong. A car dealer has to declare everything they know about a car; a private seller only has to make sure the car is as described.

2. Ask lots of questions

What damage did the car sustain? Are there any photos of the damage? Where were the repairs carried out? What parts were replaced? The insurer doesn't have to release any information about how the car became a write-off, but some well-targeted questions to the dealer can help you uncover what happened.

3. Get an inspection

This will cost you upwards of £200 – a major investment if you're attracted to the car because of its low price – but it is well worth the cost. An inspector knows what to check and could find accident damage that you’ve not spotted. The AA, RAC, Dekra and Autolign all offer inspection services that could save you from buying a potentially unsafe car.

4. Pay for a history check

Accident damage isn't the only thing you need to think about. Just as with any secondhand car, a history check will tell you if the vehicle has been stolen or is subject to any outstanding finance.

5. Be wary of newer cars offering really big savings

The old adage, 'If it looks too good to be true, it probably is' definitely applies here. A really low price on a newer car could be a sign that the repair work has been done to a budget and isn't of satisfactory quality.

6. Avoid cars that could have chassis damage

Bodywork damage can be relatively easy to fix – but chassis damage will continue to cause headaches even if a repair has been attempted. You should be doubly careful if you discover the car has had a problem in this area.

If you think a Cat N car is worth the gamble and you've decided to buy one, there are two further things to consider:

7. Tell your insurance company

Make sure you inform your insurance company that the car is a Cat N. It'll likely have to be noted on your policy, otherwise you risk having any claim turned down in the future.

8. Investigate a warranty

Some used warranty suppliers will provide cover for Cat N cars. It could be a surprisingly cost-effective way of giving yourself some peace of mind about your new purchase and any repairs that have been done to it.

For all the latest reviews, advice and new car deals, sign up to the What Car? newsletter here

Find a great deal on a used car with What Car? >>