Insurance write-offs explained: what is the difference between Cat A, Cat B, Cat S and Cat N?

Browse through any used car or classified ads website and there’s a good chance you’ll come across something with a ‘Cat’ label attached to it, followed by one of four letters: A, B, S or N. This means that vehicle has been classed under a write-off category – introduced in 2017 by the Association of British Insurers (ABI) – with the specific letter denoting the level of damage sustained after an accident. 

Here’s a quick overview of each insurance write-off class, from most severe to least, and the characteristics that define them:

Cat A

- Irrepairable structural damage

- No section of the car is usable

- Car must be scrapped

- Whole car will never be roadworthy again 

Cat B

- Heavy structural damage

- Can be stripped for still usable parts 

- Body/structure must be scrapped

- Part of the car will never be roadworthy again 

Cat S

- Light structural damage

- Can be repaired 

- Suitable for road-use following successful MOT test

Cat N

- No structural damage, instead the damage is often to mechanical or cosmetic components

- Can be repaired 

- Suitable for road-use following successful MOT test

While you might instinctively want to steer clear of anything with a Cat badge attached, you could be missing out on a serious bargain. According to data from the Driver and Vehicle Licensing Agency (DVLA), more than 560,000 cars were written off by insurance companies in 2024. 

This typically happens because the damage they’ve sustained would cost the insurer more than the car’s pre-accident market value (otherwise known as Actual Cash Value) to repair. This is due to the increasing amount of expensive and sensitive technology found in new models, and the rising cost of fuel and inflation leading to increased garage bills. 

As a result, a minor shunt that would once have cost a few hundred quid to fix is now likely to cost thousands once the repair work and the recalibration of systems are factored in. Some written-off cars often get sent to the scrapyard to be dismantled for parts or crushed; however, others are still fit to return to the road and are typically sold on once they’ve been repaired. Many see this as an opportunity to get in on a bargain, but should you? 

To help you make an informed decision, we’ve created this all-encompassing guide. Keep reading for a rundown of the most asked question on insurance-write offs, plus a deep-dive into each of the various categories. 

What does insurance write-off mean?

Sometimes also called “total loss”, an insurance write-off is any instance where an insurance company has decided that the costs associated with repairing a damaged car to a safe, acceptable standard would be higher than the value of the car itself. This could range from a few minor scratches on the bodywork to a complete failure of the engine; and it’s because of this wide scope of conditions that the various write-off classifications have been created. 

Why is a car a write-off?

The most common scenario is if the car has been involved in an accident. Once reported, the vehicle’s insurer will check the damage against various criteria – from the vehicle’s age and mileage to overall condition – to determine if it should be labelled as a write-off. Thereafter, depending on the terms of the insurance agreement, one of the involved parties will be required to pay for any damages incurred.

Do you still own your car if it becomes an insurance write-off?

No, you don’t. Since it is no longer road-legal, your insurance company will pay you a settlement amount – with your excess deducted – and take full ownership. You will be given the option to buy the vehicle back if it is a Cat N or Cat S vehicle, but if it has been damaged to the point of Cat A status, you will not. Instead, the insurers will begin the process of getting it scrapped. If it is a Cat B, you may be able to purchase it if you have the appropriate permit (more on this later). 

What do you do if I don’t agree with your insurer’s valuation of the vehicle?

1. Find out what the true market value of your vehicle is by searching it up against identical model/trim examples, with a similar mileage and history.

2. See if you can figure out precisely what damage has been caused, and how much it should cost to get repaired by browsing for quotes.

3. Contact your insurer with as much evidence as possible, making them aware of your concerns

4. If a compromise cannot be met, ask your insurance company for a Data Subject Access Request (DSAR), which will provide you with a summary of how they calculated their valuation. 

5. Should you remain unsatisfied and intent on taking matters further, you should look to seek legal advice at this point.

Do I have to tell the DVLA if my car is an insurance write-off?

Yes, this is a non-negotiable. Failure to do so could even land you a hefty fine of up to £1000, so we’d suggest alerting them sooner rather than later by following one of the two methods:

1. On the DVLA website - This is the easiest way. You simply visit the GOV.UK website and follow the instructions. Make sure you’ve got your insurance company details and 11-digit reference number from your V5C (or logbook) to hand, as well as your vehicle’s registration number. 

2. By post - On your V5C will be a yellow section, titled ‘sell, transfer or part-exchange your vehicle to the motor trade’. Fill this in with any relevant information and send it to the DVLA’s address. Make sure you clearly state your name, address and date to avoid any delays.  

Once the DVLA has been notified, you should receive a letter confirming that you are no longer the owner of the car. You’ll also be issued with a refund for any pre-paid vehicle tax you have remaining, provided you pay annually, and are eligible for a claim

Can I sell my written-off car, and if so, how?

Yes, you can sell your insurance write-off, but it’s not quite as simple as it would be a fully-functioning, road-legal vehicle. There are several key measures that have to be taken, and authorities that need to be alerted – the DVLA, Motor Insurance Anti-Fraud & Theft Register (MIAFTR) or even the police, in some instances. Even if you’re selling the car privately, it’s imperative that you specify which write-off category your car is registered as, and that you’re completely transparent about the damages present. 

Typically, these are the steps you should take: 

1. Start by telling your insurance company that you intend to buy it back

2. Agree on a price and a write-off category, and then fix a collection date

3. Alert the DVLA of your decision and make them aware of the vehicle’s condition

4. Once you’ve collected your vehicle, get an inspection done by a professional mechanic or garage, so they can provide a clear run-down of just what needs fixing

5. Pull together all the necessary documents and paperwork, including any notes provided by the vehicle inspectors clarifying how much the repairs are estimated to be

6. Take lots of photos with as much attention to detail as possible of the damaged areas, but also, of the sections that still remain in good condition

7. Think of a realistic price, based on the car’s market value minus the expected repair costs as per the inspection report

8. Create an advert on a used car sales website and list your vehicle: remember to be completely honest about the car’s category (A, B, S or N), and therefore, whether or not the car will ever be drivable or must be picked for parts

9. Once you’ve found a willing buyer and agreed on a value, you must create two receipts confirming the transaction – one for you, and one for the buyer

10. Notify the DVLA once more that you have sold the car (this is a relatively quick process on the DVLA website) 

11. Pass the keys and any accompanying documents to the new owner, and say your farewells

How do you check if a car you’re buying is an insurance write-off?

First and foremost, the seller should clearly identify the car’s condition on the advertisement if it’s a write-off. This is normally highlighted high up on the overview section, or included in the vehicle description. Just to be on the safe side, we’d recommend paying for a history check by using one of the many online tools. 

How do I buy an insurance write-off?

An insurance write-off could be a tempting purchase – provided you’re fully aware of the risks involved and have an understanding of the car and the cost of the work. If you’ve found an advert that you’re interested in, follow these steps: 

1. Pay for a history check - If a seller is trying to make money by advertising a repaired write-off without disclosing the fact, this should show up in a history check. As well as confirming whether a car has previously been written off, some checks will provide you with details and photos of the damage the car sustained, helping you to judge whether or not you should buy it. As with any used car, a car history check will also tell you whether the vehicle has been stolen or is subject to any outstanding finance, along with the results and mileage data from previous MOTs.

2. Get an inspection - This will cost you upwards of £100, but it’s worth the price. An inspector knows what to check for and could find accident damage that you haven’t spotted. The AA, My Car Inspections and the RAC all provide inspection services that could save you from buying a potentially unsafe car.

3. Ask lots of questions - The insurer doesn’t have to release any information about how a car became a write-off, but some well-targeted questions to the seller can help you uncover what happened. The seller should be able to tell you what damage the car sustained, what parts were replaced and where the repairs were carried out. If they seem to be unsure of something or unwilling to answer certain questions, it may be best to walk away.

4. Tell your insurance company - Make sure you inform your insurance company that the car is an insurance write-off. It will probably have to be noted on your policy, otherwise you risk having any claim turned down in the future. Unfortunately, most insurance providers will charge more to cover a written-off car.

5. Investigate a warranty - Some used warranty suppliers will provide cover for Cat N and Cat S 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.

Should I buy an insurance write-off?

This is subjective, and depends on a number of factors: how confident are you about sorting the repairs yourself? Do you know someone that could do the repairs if not, and how confident are you that they will do a good job? Is the seller legitimate? Are there any guarantees in place in case you’ve been missold a vehicle that is more damaged than advertised? 

You need to consider every possible scenario and make sure every question is answered by the seller before you decide to purchase a Cat N or Cat S vehicle. But if you tread carefully, have done enough research, and work with the right people to ensure that the vehicle comfortably passes its MOT, you could be getting a bargain. 

Remember: some write-offs have very minor damage accrued, be it LED headlights, worn suspension bearings or damage to a body panel. Faults like these are not difficult to sort, but it is imperative that there are no deeper-lying issues beyond what can be seen or what has been advertised.

What is the process for turning an insurance write-off into a road-legal vehicle? 

If you’ve gone for a Cat A or Cat B vehicle, you’re likely a tradesperson who knows what you're doing, and aware of the procedures for extracting parts. So we’ll focus instead on those that have purchased a Cat N or Cat S vehicle, and want to find out how they can put their new car on the road again. 

1. After you’ve had your vehicle inspection, make a list of all the specific jobs that need completing, as suggested by the inspector 

2. Find a suitable workshop that has the time and means to complete the work. It is often better to stick with one workshop rather than switching between several, because it means they are aware of what jobs have already been completed and allows for more consistency with repairs

3. Once your Cat N or Cat S vehicle has been completed, you’ll need to get a new MOT. This may even be offered by the workshop that fixed it

4. Provided it passes its MOT, you’ll then need to inform the DVLA of your intentions to put it back on the road. For a Cat N vehicle, you can keep the pre-existing V5C; for a Cat S, you’ll need to get a new one by completing a V62 form

5. Finally, you’ll need to get your vehicle insured. It’s worth mentioning precisely what work has gone into the vehicle, so they can give you an accurate estimate

6. Once all your forms are in order, and the vehicle deemed safe again to use on the road, you may do so

7. It’s worth noting that your vehicle’s insurance write-off status can never permanently be removed – so it will remain a Cat N or Cat S for the life of the vehicle. This is to future proof it and make sure other owners are aware of its history

Is it worth buying a Cat A, B, N or S car?

There is no right or wrong answer here, it comes down to personal circumstances. But for some clarity, What Car? content editor, Jack Mortimer, says: “With the cost of repairing a car on the rise, many write-offs are no longer the crusher-bound wrecks many of us imagine. With enough knowledge about the damage and how it can be fixed, you might be able to get the car of your dreams for thousands less than its typical value.

“That said, even if the car is up to your standards, it’s worth remembering that you’ll typically have to pay more to insure a written-off car and, when it’s time to sell it on, you might not get as much as you would with an accident-free equivalent. As a result, it’s vital that you weigh up the costs before you decide what to buy.”

Our next section delves into the specifics of Cat A, Cat B, Cat N and Cat S vehicles types: what they are, the advantages and disadvantages and whether you should buy one.

CAT A - What is the meaning of a Cat A car?

The highest-possible designation for an insurance write-off, Cat A cars are vehicles that are completely unsalvageable: the body, chassis, panels and even interior elements can never be repaired, resold or reused again. This is because the damage inflicted has been so severe that putting any section of the car on the road again could make its donor car a liability. They are destined for the scrapyard, unfortunately. 

Should I buy a Cat A car?

It is illegal for a Cat A designation car to ever be sold – even in parts. If you see one for sale, or suspect one is being advertised online, you should report it to the marketplace’s higher powers at once. 

CAT B - What is the meaning of a Cat B car?

This designation stands for ‘break’ and means that, although these cars have suffered extensive damage and are beyond repair, they contain some parts that can be recycled. These could include sections of the engine or transmission that are still working, or bits of the cabin that remain in good condition. Once any salvageable parts have been removed, the bodyshell must be crushed. You must also hold an End-of-Life (ELV) permit to be able to buy a Cat B vehicle. 

What are the advantages of a Cat B car?

- You could gain valuable parts for below market value

- Parts would likely be of manufacturer-standard quality

- It is environmentally friendly, since you’re reducing waste by recycling still usable parts

What are the disadvantages of a Cat B car?

- You are not allowed to dismantle a Cat B vehicle without the correct licenses 

- ELV permits can be costly; starting from £4,000 in initial costs, before you pay a rolling annual fee to continue holdership 

- You will be responsible for making sure the parts are in working order before selling them on

- The car will never be drivable in its factory form

Should I buy a Cat B car?

Buying a Cat B vehicle may be a bit of a gamble: it could be a potential moneymaker if you’ve got the right permit, or you could find that the parts you’re salvaging aren’t actually as valuable as you first thought. So, do your research, ask plenty of questions, and have a clear idea of whether the costs involved will be worth it. If you don’t have the correct permits or skills in place, and money to spend, you shouldn’t entertain the prospect as it’s far too complicated. 

CAT S - What is the meaning of a Cat S car?

The ‘S’ stands for ‘structural’, which means cars in this category have sustained damage to their structural frame, but they can still be repaired and resold. A Cat S car could have a bent or twisted chassis, or a crumple zone that has collapsed in a crash, so it must be professionally repaired and inspected before being allowed back on the road. Insurers are legally bound to destroy the original logbook of a Cat S car, and the repairer or buyer of it must apply for a replacement document that will have ‘Cat S’ stated on it.

What are the advantages of a Cat S car?

- Could be as much as 50% cheaper than non-Cat alternatives, depending on the level of damage

- Professional mechanics could take these on and have access to luxury cars without having to pay labour costs  

What are the disadvantages of a Cat S car?

- Lower purchase price could mean higher expenditure on repairs

- Resale value will almost certainly be lower than a non-Cat example

- Insurance could be noticeably higher

- You’ll need to get the repairs done by someone that’s trusted

- Any existing manufacturer warranty is likely invalidated

Should I buy a Cat S car? 

Provided you’re skilled and knowledgeable enough to fix the car yourself, or know somebody who is, buying a Cat S car could save you thousands of pounds. Make sure the work has been completed diligently, the vehicle passes all of its regulatory tests, and you are completely satisfied with how the car drives and feels once it’s back on the road. This could be the ideal solution for someone who’s looking for a bit of short-term fun – so long as they accept they probably won’t get market value back for it.

CAT N - What is the meaning of a Cat N car?

The second and last designation of the write-off categories that can be repaired and resold. The ‘N’ in the name stands for ‘non-structural’ and denotes that, while these cars have been involved in an accident, they haven’t suffered damage to their structure. Instead, they have probably sustained cosmetic damage to bumpers or other panels, or they might have mechanical or electrical problems that aren’t economically viable to repair.

Although the structural integrity of a Cat N car will still be at an acceptably safe standard, it might not be drivable, and some safety-critical parts, such as brakes, steering or suspension components, might need to be replaced. Although the DVLA must be informed that a car is a Cat N write-off, this information isn’t stated in the car’s logbook, so it’s important to get a history check to see if a car is listed as Cat N. 

What are the advantages of a Cat N car?

- Primarily, Cat N cars tend to be much cheaper to purchase (sometimes as much as 20-40% less)

- Could have it repaired and back on the road for much less than an identical non-Cat-designated vehicle 

What are the disadvantages of a Cat N car?

- Imperative to have it checked and repaired by a professional mechanic   

- Resale value will almost always be less than a non-Cat vehicle

- You might easily underestimate the value of repairs (or be manipulated into false repair costs by the previous seller)

- Insurance will be higher

Should I buy a Cat N car?

It’s a tempting thought, and could prove to be a massive bargain if you get the right car at the right price. Provided you’ve had the right advice from your local workshop, and you’re absolutely convinced by both the seller and the vehicle, a Cat N could end up being a shrewd investment if you know what you’re doing.

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