Buying guide
Insurance Write-Off Categories: Category S, N, A and B Explained
When an insurer decides a damaged car is uneconomic to repair, it is categorised as a write-off. Learn what Category S, N, A and B markers mean for safety, insurance costs, and resale value.
What is an insurance write-off?
When a car is involved in an accident, flood, or fire, the insurance company sends an assessor to estimate repair costs. Insurers use official repair guidelines, original manufacturer parts, and approved body shops.
If the estimated repair bill exceeds a certain proportion of the car's pre-accident value (often between 50% and 70%), the insurer declares the car a total loss ("write-off"), pays the owner the market valuation, and sells the salvage to a breaker or repairer.
The 4 insurance write-off categories
The Association of British Insurers (ABI) salvage code divides damaged vehicles into four distinct categories based on whether the damage was structural or non-structural:
The 4 UK ABI insurance write-off categories (A, B, S and N) and road legality
| Category | Damage Level | Can it return to the road? | Description |
|---|---|---|---|
| Category A (Scrap) | Severe total loss | No (Never) | Extreme damage, burnt out or contaminated. Entire car must be crushed; no parts can be salvaged. |
| Category B (Break) | Heavy structural damage | No (Never) | Body shell and chassis must be destroyed. Reusable non-structural parts can be salvaged and sold. |
| Category S (Structural) | Repairable structural damage | Yes (after repair & MOT) | Damage to structural components such as chassis rails, A-pillars, or suspension mounts. Repaired professionally. |
| Category N (Non-Structural) | Repairable non-structural damage | Yes (after repair & MOT) | No structural integrity loss. Damage limited to panels, lights, electrical wiring, or minor cosmetic parts. |
Category S vs Category N: What is the difference?
The key distinction is whether the car's structural frame was compromised:
- Category S (Structural): The car has sustained damage to its load-bearing framework. This includes front chassis legs, crossmembers, inner wings, B-pillars, or rear quarters. If repaired correctly on a jig to manufacturer tolerances, the car is safe, but substandard repairs can affect crash safety.
- Category N (Non-Structural): The chassis and crash structures remained intact. The vehicle was written off due to cosmetic panel damage, bumper impact, stolen parts, vandalism, or electrical faults. The repair is typically simpler and does not involve structural alignment.
Old categories (C and D) vs new (S and N)
In October 2017, the UK insurance industry replaced the old financial-based Category C and D system with the structural-based Category S and N system:
- Category C: Repairable, but repair cost exceeded vehicle pre-accident value (mostly equivalent to Category S).
- Category D: Repairable, and repair cost was less than vehicle value, but uneconomic due to hire car or parts delays (mostly equivalent to Category N).
Cars written off before October 2017 continue to show Category C or D on their history records.
How write-off status affects price and insurance
Buying a written-off car involves both financial advantages and trade-offs:
- Purchase Price: A Category S or N car should be 20% to 40% cheaper than a clean-history car of identical age and mileage. Never pay full market value for a written-off car.
- Insurance Premiums: Some insurers decline to cover Category S or N cars, while others charge higher premiums or require a post-repair engineer inspection report.
- Future Resale: When you come to sell the vehicle, prospective buyers and dealerships offering part-exchange will offer significantly less.
Should you buy a Category S or N car?
A Category N car can represent excellent value if the damage was superficial and the repairs were carried out to a high standard with photographic evidence.
If considering a Category S vehicle:
- Ask the seller for photos of the pre-repair damage and invoices for replacement parts.
- Commission an independent mechanical and bodywork inspection from an engineer or motoring organisation.
- Get insurance quotes before putting down a deposit to ensure affordable cover.
Frequently asked questions
Learn more about checking a used vehicle in our guides on how to check a used car, checking outstanding finance, and checking stolen markers.
FAQ
What is the difference between Category S and Category N?
Category S indicates structural damage (such as chassis, crumple zone, or suspension mounting damage) that was judged repairable. Category N indicates non-structural damage (such as body panels, electrics, or bumper clips) where the car's structural frame was unaffected.
Can a Category S or Category N car legally go back on the road?
Yes. Both Category S and Category N vehicles can be legally repaired and returned to UK roads once they pass a valid MOT test. Category A and Category B vehicles can never be put back on the road.
Does an insurance write-off appear on the V5C logbook?
Category S write-offs are recorded on the V5C logbook with a permanent note stating that the vehicle has been salvaged. Category N write-offs are not always printed on the V5C, meaning you must use a vehicle history check to detect them.
How much cheaper should a Category S or N car be?
A Category S or N vehicle typically sells for 20% to 40% less than an equivalent non-damaged car, reflecting the salvage history and potential impact on future resale value.