Independent, impartial advice for car buyers and car owners

Find an Expert Rating: 

Should I buy a Cat S or Cat N used car?

Now and then you’ll find a used car for sale with either Cat S or Cat N next to it. What does this mean and what do you need to know?

Our Expert Partners

Looking for a new or used car? Our commercial partners can help you find the right car at the right price.
Motors 600x300

Find your next car with Motors.co.uk
Find out more

Cazoo 600x300

Find your next car with Cazoo
Find out more

Auto Trader logo 600x300

Find your next car with Auto Trader
Find out more

Carwow logo 600x300

Find your next car with Carwow
Find out more

Now and then you’ll find a used car for sale with a cryptic description next to it: Cat S or Cat N. What does it mean and what do you need to know before buying a car with one of these two designations?

A Cat S or Cat N designation means that a car has been written off by an insurance company, usually after an accident, and then either repaired or left as it is with minor damage. It’s perfectly legal for a car with either of these designations to be sold, but they are usually a fair bit cheaper than the equivalent car that hasn’t been written off.

Here we look at what the letters mean and how to weigh up the savings.

What the categories mean

There are four categories for accident damaged vehicles (last updated in November 2019 when they replaced the old A,B,C and D ratings), conforming to a code of practice produced by and supported by the Association of British Insurers (ABI) & Lloyd’s Market Association (LMA).

This code sets best practice for the supporting organisations when disposing of motor vehicle salvage to ensure that damaged vehicles are correctly categorised. The ABI states that ‘the purpose of the Code is to protect the public, detect and deter insurance fraud and other criminal activities.’

If an insurer has written off a car, ownership passes to them, the owner is paid out and the car is given a Category which is entered into the Motor Insurance Anti-Fraud Theft Register (MIAFTR).

The code requires all motor vehicles salvaged in this way to be categorised as one of the following Codes:

Category A: Scrap

A Cat A car is so badly damaged that it is not suitable to be repaired in any way, and must be crushed without any parts being removed and re-used.

This is applied to the most badly damaged of cars, such as those that have suffered a major fire or where emergency workers have had to cut away large sections of the vehicle to rescue people trapped inside. The extent of the damage means that it is not considered safe for any single part of the vehicle to be used again.

Category B: Break

Cat B means that the level of damage makes a car unsuitable for repair. However, after inspection by a qualified person, certain usable parts can be recycled and re-used on another vehicle.

This category often applies to cars that have suffered heavy damage in one area but are untouched elsewhere. A common example is a head-on collision, where the front half of the car may have been extensively damaged but the rear half is largely intact.

Category S: Repairable Structural

A Cat S car has sustained some structural damage, but is not beyond repair. It has been inspected and judged as a repairable vehicle, which has sustained damage to any part of the structural frame or chassis. Whilst it can be repaired safely, it’s likely to take quite a bit of work.

The insurer (or self-insured owner) has decided not to repair the vehicle because the cost of the repair is likely to exceed the market value of the vehicle, however it is perfectly legal for someone to buy the damaged vehicle and repair it to a safe and legal standard.

Category N: Repairable Non-Structural

This category denotes a repairable vehicle that has not sustained damage to the structural frame or chassis. In other words, damage to external panels or components that can easily be replaced, although the cost of doing so means that the insurer orself-insured owner has decided not to repair the vehicle.

There may be some safety-critical items that need replacement (such as steering or suspension parts), but the underlying structure of the car is undamaged.

Emergency workers have had to cut away large parts of this extensively damaged car to rescue people stuck inside, so it’s definitely a Category A

Which cars can be repaired and sold?

Cat A and Cat B cars should never re-appear on the road and must be destroyed, but Cat S and Cat N can be repaired. You must tell the Driver and Vehicle Licencing Agency (DVLA) if your vehicle has been written off by your insurance company or face a fine.

You may also like: What is an insurance write-off?

A Category N rating can be applied even if a car has only quite minor damage. For example, the price of a door panel, complete bumper or even an electric mirror or headlamp assembly plus fitting and painting can be decisive in making the cost of repair uneconomical on a car that’s not worth that much money anyway.

Older cars which have been put into Category N are sometimes bought back by their owners after the insurer settles and sold as an easy repair job for a buyer who is prepared to fit second-hand parts, or that buyer can simply choose to live with cosmetic damage which doesn’t affect its MOT certificate. However, remember that Category N cars can still be classed as such when the steering or brakes may have been affected by an accident.

Sadly, flooding has become more common in the UK in recent years, with many parked cars becoming waterlogged. It doesn’t automatically lead to the car being written off, but if that happens it generally falls into N. Some private sellers could neglect to mention this, as once a car has been dried out and professionally cleaned, flood damage can be very hard to spot. However, items like brakes, starter motors and catalytic converters can be affected by water damage and could fail at any point.

Warning signs for a car that may have been flood damaged may include a damp or musty interior or lots of air freshener, damp carpet in the footwells or more condensation on the inside of the windows than you’d expect.

Buying a Cat S or Cat N car

There are no set used car values for Category S or N cars. In fact, cap hpi, the UK’s leading vehicle history checking company, which also provides used car valuations, for the trade and public, doesn’t give values for Cat S or N cars, so they become literally what any buyer is prepared to pay for them.

The savings are often tempting. Taking a random example, in June 2021 we found a Cat N 2018 BMW 118d with lower-than-average mileage advertised by an independent dealer at £10,495. The valuation for a dealer price for a regular equivalent with the higher average miles started at £2,000 more.

 “We recommend that buyers considering a used bargain conduct a thorough hpi check to reveal if the car has been declared an insurance write-off and importantly, what Category write-off it is,” says Steve Wren, head of product for cap hpi.

“Not all written-off cars need to be avoided, but we strongly recommend you approach any potential purchase with your eyes open and all the facts. Category S (formerly Cat C) and N (formerly Cat D) write-offs that have been professionally repaired and declared roadworthy can sometimes present a real bargain, but you need to assure yourself that the car is a safe and roadworthy purchase.

“The hpi check will help you uncover if the car has such a history. Finally, we recommend that you get an independent, professional assessment of any written off vehicle to ensure it has been repaired to an appropriate standard.”

Used car dealers are obliged to declare that the car is a Cat S or Cat N. It must also be clearly stated in any advertisement. Furthermore, as a vehicle history check will flag up whether the car is an insurance write-off, most dealers will publish the results of that search (however that shouldn’t stop you doing your own research).

Category S cars will need to have been repaired with professional equipment (for example, replacing the ‘crush boxes’ front and rear which are destroyed in a moderate impact, then re-aligning the attachments points for the steering, panels etc). However, there is no legal requirement for the repairs to be inspected before the car returns to the road, so you have no guarantee that the repairs have been conducted to a suitable standard. If you’re about to invest thousands on a Cat S vehicle, a professional inspection is essential.

The extra costs may not end there either. According to Money Supermarket, some insurers won’t cover Category cars, so a check with your own provider or an insurance comparison site may be wise. Cat N will be less of a problem than a Cat S.

Protect your investment with a vehicle history check

If you’re worried that a used car that you’re looking at may have suffered accident damage, a vehicle history check can easily put your mind at ease. Here at The Car Expert, we’ve partnered with both CarGuide and CarVertical to provide you with options for checking the history of any used car before you buy

  • CarGuide not only shows you a car’s history, but can also predict future servicing costs
  • CarVertical offers full history details, photos where available, and lots of useful buying advice

Latest car buying features and advice

Russell Hayes
Russell Hayeshttps://amzn.to/3dga7y8
Russell Hayes’ early career was 14 years of motoring journalism in print, television and online. He worked for What Car? and Complete Car magazines, the BBC's original Top Gear programme and Channel 4's Driven. Since 2007 he has written motoring history books on subjects including Lotus, TVR, the Earls Court Motor Show, the Volkswagen Golf, Volkswagen Beetle and Bus and the original Aston Martin V8. Now a full-time author, two more books are in the pipeline for 2023 and 2024.