9 min read
A written-off car is not necessarily a badly damaged car. "Written off" is an insurance decision, not an engineering one: it means the insurer has decided it is not economic for them to repair, given the car's market value, the repair estimate, hire costs and salvage value.
Since 2017 UK insurers have used four salvage categories, set out in the ABI Salvage Code. Two are based on damage severity, two on economics.
Category A — scrap
The most severe. The entire vehicle must be crushed, including every part. Nothing may be salvaged and reused, not even undamaged wheels or a stereo. Typically fire damage, severe flood contamination or a total structural loss.
Category B — break for parts
The bodyshell must be crushed and can never return to the road, but serviceable parts may be removed and resold. If you are buying second-hand parts, they may legitimately have come from a Cat B vehicle.
Category S — structurally damaged, repairable
S stands for structural. The car has sustained damage to a structural part — chassis rails, crumple zones, suspension mounting points, pillars, floor — but it can legally be repaired and returned to the road.
Structural repair is proper work. It needs measuring on a jig or with an electronic measuring system, sectioning and welding to the manufacturer's method, correct fixings, seam sealing, cavity protection and a post-repair geometry check. It should also include recalibration of any ADAS cameras and radar disturbed by the repair. Done to standard, a Cat S car is safe. Done in a shed, it is not, which is why the category carries a stigma.
Category N — non-structural damage
N stands for non-structural. There is no structural damage — but the repair still exceeded what the insurer was prepared to spend. Cat N cars are frequently cosmetically damaged only: bumpers, wings, doors, bonnets, lights, or a panel with expensive paint.
Important nuance: Cat N can still include damage that matters, such as steering, brakes or airbags, because those are not classed as structural. So Cat N does not automatically mean 'just a scratch' — it means 'not structural'. Always have it inspected.
Why an insurer writes off a repairable car
The threshold is economic, not technical. Once the estimate approaches roughly 50-60% of the car's market value — the exact figure varies by insurer — writing it off is cheaper for them than repairing it.
This means older cars are written off very easily. A ten-year-old hatchback worth £1,800 can be declared a total loss by a damaged bumper, wing, headlamp and airbag deployment, even though the same damage on a three-year-old car would simply be repaired.
What it does to resale value
- Cat S and Cat N are permanently recorded against the VIN and will appear on any HPI or vehicle history check
- A repaired Cat N car typically sells for around 20-30% less than an equivalent clean-history example
- A repaired Cat S car typically sells for around 30-50% less, sometimes more on premium models
- Some insurers will decline or load cover on a previously written-off vehicle, and some finance companies will not lend against one
- You are legally required to disclose the category when you sell — misrepresenting it can void the sale
If you'd rather keep and repair the car
You can. When an insurer declares a total loss they offer you the market value and take the car as salvage. You have the option to retain the vehicle instead: the insurer pays the settlement less the salvage value, and you keep the car and arrange the repair yourself.
That makes sense when the car is worth more to you than the book figure — low mileage, known history, a spec you cannot easily replace, or a specialist vehicle. It rarely makes sense if the damage is structural and the car has little value to begin with.
Two things to get right. First, don't accept the settlement figure without challenging it if it is low: send comparable advertised examples with similar mileage and specification. Second, get an independent repair estimate before you decide — an insurer's write-off decision reflects their costs, not necessarily what the repair actually needs.
Where we come in
We assess accident-damaged vehicles honestly and tell you which side of the line you are on. If a car has been written off and you want to retain and repair it, we will estimate the work properly, tell you plainly if we think it is not worth doing, and repair it to BS10125 standard if it is.
As an RAC approved repairer working with all major UK insurers, we also handle claims directly — including the cases where the insurer wants to total a car we can repair correctly.
Frequently asked questions
- Can you still drive a Category S or Category N car?
- Yes, once it has been properly repaired. Cat S and Cat N vehicles may legally return to the road. Cat S must be re-registered with the DVLA before it is used again; Cat N does not require re-registration but still needs to be roadworthy and, where due, MOT'd.
- Is Category N worse than Category S?
- No — Cat S is the more serious of the two. Cat S means structural damage; Cat N means the damage was not structural but the repair cost exceeded the car's economic value.
- What is the difference between Cat A and Cat B?
- A Cat A vehicle must be crushed in its entirety with no parts salvaged. A Cat B vehicle's bodyshell must be crushed, but usable parts may be removed and resold.
- Can I keep my car if the insurer writes it off?
- In most cases yes. You ask the insurer to let you retain the salvage: they pay the settlement minus the salvage value and you keep the vehicle to repair yourself. Confirm the category first, as it affects re-registration and future value.
- How much value does a write-off category take off a car?
- As a guide, expect roughly 20-30% off market value for a repaired Cat N and 30-50% for a repaired Cat S, depending on the vehicle and the quality of the repair documentation.
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