Cat A, B, S and N explained

You may have heard about written-off cars, but what exactly does that mean?

Cars that are ‘written off’ have been involved in an accident of some sort and deemed by an insurance company as either unsafe to ever be on the road again, or uneconomical to repair – i.e., the cost to repair the damage is 50% or more of the vehicle’s current valuation. This can include damage to the car’s exterior, motor, chassis, or other parts.

Key Takeaways

• Cat A & B: Irreparable vehicles that must be scrapped; Cat B allows for salvageable parts.
• Cat S & N: Repairable vehicles; Cat S has structural damage, while Cat N is non-structural or cosmetic.
• Write-off Criteria: Insurers typically write off cars when repair costs exceed 50% of the vehicle’s market value.
• Buy-back Options: Owners can often buy back Cat S or N vehicles to repair and return them to the road.
• Value Impact: Written-off cars are cheaper to purchase but often carry higher insurance premiums and lower resale values.

The damaged vehicle will be given a label by the insurer depending on the severity of the accident . There are now four insurance categories for damaged cars, AKA category write-offs: Cat A, B, S, and N. Cat S used to be known as Cat C, and Cat N used to be known as Cat D.

Read on to learn how to sell your car , how scrapping works, and what your options are as the owner of a category write-off vehicle.

Label	Definition	Outcome
Cat A	The vehicle is beyond repair, never to be driven again, and can’t be sold as parts	The vehicle is crushed and scrapped at an ATF (authorised treatment facility)
Cat B	The vehicle is beyond repair, never to be driven again, but some parts e.g. the gearbox may be stripped and sold	The vehicle shell is crushed and scrapped at an ATF
Cat S (formerly Cat C)	The vehicle sustained serious structural damage, but can be repaired and driven	The cost of repair may outweigh the value of the vehicle, but destruction is not enforced
Cat N (formerly Cat D)	The vehicle sustained cosmetic or very minor, repairable damage	The vehicle should be repaired by a licensed mechanic, and proof of service history should be kept by the owner

Not all write-offs will make your car worthless or unsellable. Small knocks and bumps can end up writing-off your car, especially if it’s older and worth only a few thousand pounds. Something as trivial as a replacement bumper could also ‘write your car off’.

But let’s take a look at what each category means and why buying a write-off could be a good idea after all.

Category A, B, S and N explained

• What happens when my car is written off?
• What is a Category A write-off?
• What is a Category B write-off?
• How do I get a Cat A or Cat B vehicle scrapped?
• What is a Category S write-off?
• What is a Category N write-off?
• How do I buy back and repair a Cat S or N write-off?
• Does vehicle age affect the write-off category?
• Should you buy a written-off car?

What happens when my car is written off?

Your insurer takes ownership of the car and pays you out. Here is how it works. If your car has been in an accident and sustained any level of damage, your insurer will have the vehicle assessed against their own criteria. If they judge the damage is costly enough (anything from 50% of the current vehicle value), they will assign it one of four ‘write-off’ labels: Cat A, B, S, or N.

When your car is written off by your insurer, the ownership transfers to them. You get an insurance payout as compensation, while they keep the vehicle. When people say their car or van was “written off”, this is normally what they mean.

In the cases of Cat A and B (more on these below), you would never expect to be able to buy back the vehicle for repair. When your car or van has sustained damage that the insurer classes as irreparable, even if you’re a skilled mechanic and believe you can save it, it will be illegal for you to ever use that car on the road again. Read on below for information on the necessary scrapping arrangements.

When insurers take ownership of Cat N or S vehicles, where the damage is repairable or even minor, they often sell them on (it’s legal) within the used-car market. However, you do have the right to buy your written-off vehicle back from your insurer and get it fixed, out of your own pocket. Learn the steps to do this in our section on Cat N and S repairs below.

What is a Category A write-off?

A Category A write-off is the most serious grade a damaged car can receive. It means the vehicle is totally beyond repair and must be scrapped in its entirety. No part of a Cat A car can be salvaged, reused, or resold, not even components that might still technically work.

Cat A vehicles are crushed and destroyed at an authorised treatment facility (ATF).

What is a Category B write-off?

Category B cars are the second most serious category behind Cat A. While they’ve sustained irreparable damage and can never be driven again, their parts can be sold off. Including mechanical parts like the engine and gearbox.

The body shell is then destroyed and it mustn’t be reused as a car in any circumstances.

How do I get a Cat A or Cat B vehicle scrapped?

Your insurer will handle the scrapping arrangements with an ATF to ensure that your Category A or B write-off vehicle does not make it onto the road again, putting motorists in possible danger.

Here’s what’s required from you:

• Keep the ‘sell, transfer or part-exchange your vehicle to the motor trade’ section of your V5C logbook , sending the rest to your insurer
• Inform the DVLA online or by post that your vehicle was written off, or face a penalty of £1,000

What is a Category S write-off?

Cat S means your car has sustained structural damage. This could be as minor as a bumper being hit, or more serious, like a crumple zone being crushed or the chassis being twisted due to a heavy impact.

These cars can be safely repaired and put back on the road, but bear in mind the expense of doing this will sometimes outweigh the total value of the car.

You can still buy, insure, and sell Cat S vehicles. However, there are a few things you need to know:

• You must declare Cat S status. This is a legal requirement, and it stays on the car’s record permanently, even after a full repair
• You need to re-register with the DVLA. Once a Cat S car has been repaired, it must be re-registered before it can legally return to the road
• Insurance premiums may be higher. Most insurers will cover a Cat S car, but you should expect to pay more. You must also disclose the write-off status to your insurer, or risk invalidating your policy
• Resale value will be lower. Cat S cars typically sell for less than comparable non-write-off models on the used market, so factor that into your decision

What is a Category N write-off?

Cat N replaced the original Category D or Cat D in 2017. It is reserved for cars that have not sustained any structural damage.

That does not always mean the damage is minor. Cat N covers a broad range of non-structural issues, including:

• Cosmetic damage, like deep scratches, keying, or scrapes along one side
• Electrical or wiring faults that are deemed too expensive to repair
• Mechanical issues such as brakes or steering components, where the cost of parts and labour outweighs the car’s value

Unlike Cat S vehicles, a Cat N car does not need to be re-registered with the DVLA after repair. However, the write-off marker remains on the vehicle’s record and must still be declared when selling or insuring it.

Because Cat N damage can sometimes affect safety-critical parts, it is always a good idea to get an unrepaired one fully checked out by a professional before you buy.

How do I buy back and repair a Cat S or N write-off?

Yes, you can buy back your Cat S or Cat N vehicle from your insurer and arrange your own repairs. To do so, you will need to negotiate the terms with your insurer, which usually means accepting a smaller payout, or none at all. You might choose to do this if you want to:

• Repair your vehicle and keep it
• Repair your vehicle and sell it whole
• Repair your vehicle and sell it for parts

To buy back and repair your vehicle, follow these steps:

1. Negotiate: Agree on a buy-back price and payout level with your insurer.
2. Transfer Ownership: Arrange for the vehicle title to be transferred back to you.
3. Documentation: Send your V5C logbook to the insurer and apply for a duplicate from the DVLA using form V62.
4. DVLA Registration: For Cat S vehicles, ensure the status is registered with the DVLA.
5. MOT & Insurance: Complete repairs and obtain a new MOT certificate before re-insuring the car.

This is free of charge. In the case of a Cat S, you’ll need to make it clear that your vehicle has been given this label. Even once repaired, you will always have to declare that your car has been Cat S. You’ll see Cat S cars for sale, often with a lower relative valuation than their non-write-off counterparts.

For Cat S cars, you’ll need to apply to the DVLA for a replacement V5C logbook (using form V62) once repairs are complete, and the vehicle will need a new MOT before it can return to the road. Cat N cars don’t legally require a new MOT if the existing certificate is still valid, though it’s still a good idea to get one given the vehicle’s history. Having a qualified mechanic carry out a thorough inspection on top of any MOT is a smart move, especially for structural repairs, so you can get back on the road with confidence.

Does vehicle age affect the write-off category?

Not all write-offs will make your car worthless or unsellable. Small knocks and bumps can end up writing-off your car, especially if it’s older and worth only a few thousand pounds. Remember that the category is selected by your insurer, and they are unlikely to want to cover repairs, no matter how minor.

Even an older car requiring a minor and affordable repair such as a new bumper can end up being labelled a write-off by insurers.

However, keeping your vehicle in good condition and repair will always keep its value high – sometimes, you can even make the cost of the repair back and more. If your vehicle is desirable and yours is among the best condition available for sale on the used market, you’ll be fetching the best price within range.

Keeping your service history is key to ensuring strong prices; if you can prove you’ve had high quality maintenance and repairs, your buyers will have more trust in your vehicle. Don’t let an insurance category S or N put you off making repairs and keeping or selling your car, if that suits you best.

Should you buy a written-off car?

Buying a written-off car is not automatically a bad idea, but it is a decision worth making with your eyes open. Here is what to weigh up.

Potential benefits:

• Lower purchase price. Cat S and Cat N cars are typically cheaper than equivalent non-write-off models, so you could get more car for your budget
• Project potential. If you have the skills or know a trusted mechanic, a write-off can be a great starting point for a restoration or track-day build

Things to watch out for:

• Resale value. The write-off marker stays on the car’s record permanently, which can make it harder to sell and will keep the price below comparable non-write-off models
• Insurance costs. Most insurers will cover a Cat S or Cat N car, but premiums are often higher. Some providers may limit coverage or require an engineer’s report confirming the car is roadworthy before they will insure you
• Hidden damage. Even well-repaired vehicles can have issues beneath the surface. Before you commit, get a vehicle history check to confirm the write-off category, and consider a professional inspection from a qualified mechanic or approved vehicle inspection service. Inspections typically start from around £99, and they are money well spent for peace of mind

The bottom line: you can save a meaningful amount by buying a write-off, but factor in the cost of inspections, potentially higher insurance, and lower resale value before you decide.

What is a Category S write-off?

Cat S stands for Category S. It means your car has sustained structural damage — this could range from a bent chassis or crushed crumple zone to a twisted subframe caused by a heavy impact. The ‘S’ stands for structural.

Unlike Cat A and Cat B, a Cat S car can be repaired and put back on the road. But there are a few important things to know:

• Repairs must be done to a professional standard. Structural damage isn’t something to patch up cheaply. Poor repairs can affect the car’s safety in a future collision.
• The car needs a fresh MOT before it can be re-insured and driven. This applies even if the previous MOT certificate was still valid.
• You must register the Cat S status with the DVLA. This updates the vehicle’s record and is a legal requirement before putting it back on the road.
• The Cat S marker is permanent. It stays on the vehicle’s history forever and cannot be removed, even after a full repair.
• It will affect the car’s value. A Cat S car typically sells for 20–40% less than a comparable car with no write-off history, even when repaired to a high standard.
• You must declare it to your insurer. Failing to disclose a Cat S status can invalidate your policy.

You can still buy, insure, and sell Cat S vehicles legally. If you own one and want to sell, you must declare its status to any buyer.

Can a Cat S marker be removed from a car’s history?

No. A Cat S marker is permanent. Once an insurer assigns the Cat S classification to a vehicle, it is recorded on the vehicle’s history and cannot be removed — not even after a full professional repair.

This means that if you own, buy, or sell a Cat S car:

• You must always declare it to your insurer
• You must always disclose it to any prospective buyer
• The Cat S status will show up on any vehicle history check

Trying to sell a Cat S car without declaring it is illegal and could result in the sale being voided. Failing to tell your insurer can invalidate your policy. Always be upfront about the car’s history — and keep records of any repairs you’ve had done.

How do I check if a car has a Cat S or Cat N write-off marker?

The most reliable way is to run a vehicle history check using the car’s registration number before you commit to buying. A good history check will show you:

• Whether the car has ever been written off, and under which category
• Mileage history and any discrepancies
• The number of previous registered keepers
• Outstanding finance

Not every seller will volunteer this information upfront, and a Cat S or Cat N marker may not be obvious from a visual inspection alone — especially if repairs have been carried out well. A history check removes the guesswork.

If the check reveals a write-off marker that the seller didn’t declare, that’s a strong reason to walk away or renegotiate the price to reflect the car’s true market value.

How much does a Cat S write-off reduce a car’s value?

A Cat S classification typically reduces a car’s value by around 20–40% compared to a similar car with no write-off history. The exact figure depends on several factors:

• Quality of repairs: A professional repair with documented evidence will hold its value better than one with no paperwork trail
• Make and model: Desirable or newer cars tend to take a smaller percentage hit than older, lower-value ones
• Full-service history: Keeping detailed records of all repairs carried out after the write-off helps buyers feel more confident, which supports a stronger asking price

The Cat S marker is permanent, so the reduced value is something to factor in whether you’re buying or selling. If you’re selling a Cat S car, being transparent about the history and providing evidence of quality repairs gives you the best chance of getting a fair price.

Want to see what your car could be worth? Get a free valuation on Motorway and find out what dealers are willing to pay today.

Ready to sell?

Need to sell your car, or want to understand more about documentation or maintenance? Check out more of our guides here, covering everything from the paperwork you need when buying and selling, to various notices you may need to file with the UK’s driver and vehicle licensing agency. 

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