Insurance Write-Off Categories A, B, S and N: What Each Means for a Buyer and an Owner

"Written off" sounds final, and for half the categories it is. For the other half it is the start of a second life: a car the insurer paid out on, which someone repaired and put back on sale. Knowing which category you are looking at, who decided it and where it is recorded is the difference between a sensible discount and an expensive mistake.

This guide covers all four categories, what happens to the log book, how to find a write-off record, what to check before buying a repaired car, and what to do if your own car is written off.

What are the insurance write-off categories?

When an insurer writes a car off, it pays you the car's current value instead of the cost of repairing it, and it decides which category the car falls into [1]. There are four:

Category	Can it be repaired?	What happens to it
A	No	The entire vehicle must be crushed [1]
B	No	The body shell must be crushed; other parts can be salvaged [1]
S	Yes, after structural damage	Can be used again once repaired to a roadworthy condition [1]
N	Yes, after non-structural damage	Can be used again once repaired to a roadworthy condition [1]

The split that matters to a buyer is simple. A and B are the end of the car. S and N can come back, and when they do, they come back with a history that should be reflected in the price.

Who decides the category, and when?

The insurer, at the point it decides the car is not worth repairing. That decision is not just a claims department judgement; it carries a legal duty. When an insurer decides a car it insures would cost more to repair than it was worth before the accident, or it has to replace the car under the policy, it must notify DVLA whether the car is suitable for repair [2]. Since 20 February 2018 it must also say whether the damage is structural [2]. Keepers of fleets who carry their own risk instead of insuring have a parallel duty [2].

Two consequences follow from that wording, and both catch buyers out.

No claim, no category. The duty falls on the insurer, or the self insured fleet. A private owner who crashes a car and pays to fix it without claiming creates no write-off record at all. A clean write-off result in a history check means no insurer declared the car a total loss. It does not mean the car was never damaged.

The category describes the damage, not the repair. It records what the insurer saw when it wrote the car off. Whatever happened next, a careful repair at a specialist or a cheap one on a driveway, is not part of the category.

Why do insurers write off cars that look repairable?

Because the test is money, not whether a garage could fix it. The trigger in the regulations is a car that would cost more to repair than its value before the accident, or one the insurer has to replace under the policy [2]. The insurer then pays you the current value instead of the repair cost [1].

Run that rule forward and two things follow. The same damage can write off an older, cheaper car and leave a newer, more valuable one on the road, because the repair bill is similar while the value is not. And a write-off on an older car is often a statement about its value rather than about the severity of the crash. That is why the category, and the damage behind it, matter more than the bare fact that the car was written off. A Category N on a twelve year old hatchback and a Category S on a two year old SUV are very different histories, even though both say "written off".

What is the difference between Cat S and Cat N?

The frame. Category S cars were written off after structural damage; Category N cars after damage that was not structural [1]. Since the 2018 change, the insurer has to tell DVLA which of the two it was [2].

	Category S	Category N
Damage	Structural [1]	Non-structural [1]
Back on the road?	Yes, once roadworthy [1]	Yes, once roadworthy [1]
V5C when kept by the owner	DVLA records the category [1]	Owner can keep the existing log book [1]
Registration document after write-off	Destroyed by the insurer [2]	Not required to be destroyed [2]
Where a buyer sees it	Log book and history check	History check

Do not read "non-structural" as "cosmetic". The category only tells you the damage did not reach the structure. It says nothing about how much the repair cost or how well it was done, and a Category N car can still have needed a lot of work. Treat both categories as cars that need their repair checked, with S needing the closer look because the structure itself was involved.

What happened to Cat C and Cat D?

You will still see "Cat C" and "Cat D" in adverts for older cars. They are older industry labels, and they are not among the four categories GOV.UK lists today, which are A, B, N and S [1]. If a seller describes a car as Cat C or Cat D, treat it the way you would a repairable write-off today: ask what the damage was, who repaired it and when, and run a history check to see what the insurer recorded. Do not assume the old label maps neatly onto S or N; ask about the damage itself.

Can a Cat A or Cat B car ever be on the road?

No. A Category A vehicle cannot be repaired and the whole of it must be crushed. A Category B vehicle cannot be repaired either; its body shell must be crushed, though other parts can be salvaged [1]. Parts from a Category B car can legitimately end up on other cars. The car itself, as a whole, must not return.

So if a history check on a car you are looking at shows Category A or B, stop. Either the record is wrong, which the seller needs to prove with paperwork from the insurer, or the car in front of you is not what it claims to be. Ask where the car came from, and do not hand over money until you have an answer you can check.

How do you find out if a car has been written off?

You cannot rely on the seller, the log book or the MOT history alone. Here is where each category shows up:

Check	Cost	Shows Cat A or B	Shows Cat S	Shows Cat N
Asking the seller	Free	Only if they tell you	Only if they tell you	Only if they tell you
Reading the V5C	Free	No	Yes, if the owner kept the car [1]	No [1]
DVLA vehicle enquiry [5]	Free	No	No	No
MOT history [6]	Free	No	No	No
Private history check [3]	Up to £20	Yes	Yes	Yes

The free services are still worth running: the DVLA enquiry confirms what the car is and when its log book was last issued [5], and the MOT history shows each test, the mileage and the parts that failed [6]. A repaired car with a long gap in its MOT history and a recent log book is a pattern worth asking about. But none of the free services records a write-off. Citizens Advice describes a private history check, costing up to £20, as the check that tells you whether a car was written off, repaired and returned to the road [3]. Our free car check guide covers what the free services show, and our car history check guide explains where each record in a paid check comes from.

How do you read a write-off record against the MOT history?

A history check gives you the category and the date the insurer recorded. The free MOT history gives you every test since 2005 for a car, with the date, the result, the mileage and, in England, Scotland and Wales, the parts that failed [6]. Put the two side by side and the car's second life starts to show.

A car written off in the spring and back through a clean MOT a few weeks later was repaired quickly, which is neither good nor bad until you know who did the work. A car that failed its first test after the write-off on items near the damage tells you the repair needed more than one attempt. Our MOT history page explains how to read the advisories.

Should you buy a Cat S or Cat N car?

It can be a sensible buy, on three conditions: you know the category before you agree a price, the repair was done properly, and the price reflects the history. A repaired write-off is not a bad car by definition. It is a car with a recorded event that the next buyer will also see, so it should cost you less now because it will fetch less when you sell.

Work through it in this order:

Two points deserve emphasis. First, the inspection: on a Category S car especially, you are buying a repair as much as a car, and only someone who looks at the structure can tell you whether it was done well. Second, the insurance quote: ask how the category affects the premium, and get the figure before you own the car, not after. Answer every question the insurer asks accurately.

What should you ask the seller?

Ask in writing, in messages you can keep, so the answers become part of the description you are buying on [4]:

1. Has the car ever been written off, and if so, which category and when?
2. What was the damage, and which panels or parts were replaced?
3. Who carried out the repair, and can I see the invoices?
4. Has it had an MOT since the repair, and did it pass first time?
5. Have you had any problems with it since the repair?

A seller who answers all five clearly, with paperwork, is selling you a known quantity. A seller who is vague about the first question, when a history check shows a category, has told you what you need to know.

What if you are buying at an auction?

Be more careful still. Citizens Advice describes auctions as probably the riskiest way to buy a used car, usually without the legal protection you get from a trader [3]. That applies to any car, and it weighs more on one with a write-off record, because the repair is the part you most need to be able to question afterwards. If you buy a repaired write-off from a trader, you have the trader's protections. At auction you mostly have your own checks, so do all of them before you bid.

What are your rights if a seller hid a write-off?

The key is the description. Citizens Advice says that if a used car does not match the advert or the description you were given, you might have a right to a repair, the cost of a repair, or some or all of your money back [4]. A car advertised as "no accidents", or sold with an answer of "no" when you asked about a write-off, and then shown by a history check to be a Category S, is the kind of case that covers.

The same guidance also sets the limits. You are not entitled to anything if you were told about the fault and it was fully explained, or if you inspected the car and should have spotted the problem [4]. So if a seller tells you the car is a Category N and you buy it anyway, the category is not a complaint you can make later. That is one more reason to get the facts in writing, in the advert or in messages, before you pay.

What happens if your own car is written off?

The insurer will tell you whether the car is being written off and how much it will pay, which is the car's current value [1]. Then you have a few steps to follow [1]:

1. Keep your registration number if you want it. Apply to take it off the car before it goes.
2. Send the V5C log book to the insurer, keeping the yellow section for selling or transferring to the motor trade.
3. Tell DVLA the car has been written off. You can be fined £1,000 if you do not [1].

Can you keep a written-off car?

Only if it is Category S or N. The insurer pays out and sells the car back to you [1]. For a Category S car you also send the complete log book to the insurer and apply for a free duplicate on form V62; DVLA then records the category in the new log book [1]. For a Category N car you can keep the log book you have [1].

Keeping it is a decision to fund a repair. Get a repair quote first, compare it with what the insurer is deducting for the salvage, and remember that the category stays with the car, so its value when you eventually sell will reflect it.

What does the category mean when you sell?

It goes with the car. A private history check shows whether a car was written off and returned to the road [3], so any buyer who runs one will see it, whichever log book the car has. Be straightforward about it in the advert: a buyer who discovers a Category N after the sale and was told "no accidents" is the buyer in the rights section above [4]. Stating the category, the date and what was repaired, with the invoices, is both fairer and the quickest way to a sale that sticks.

The short version

Category A and B cars are finished: A is crushed whole, and B has its shell crushed while parts may be reused. Category S and N cars can return to the road once properly repaired, S after structural damage and N after damage that was not. The insurer decides the category and must report it to DVLA. A kept Category S car shows it in the log book; a Category N car may not show it anywhere a buyer would look, which is why a history check is the reliable way to find either. If you are buying a repaired write-off, get the category, the repair history and an independent inspection, and pay a price that reflects what the next buyer will see. Our write-off check page shows how the category appears in a report, and our HPI check guide covers what to ask when a seller says a car is clear.