UK Car Write-Off Categories Explained: A, B, S and N
When an insurer declares a vehicle a total loss, it is assigned a write-off category that determines what can be done with the car next. Understanding these categories — and what they mean for safety, legality, and value — is essential for anyone buying or selling a vehicle that has been in a significant accident.
The Four UK Write-Off Categories
The current write-off category system was introduced in October 2017 by the Association of British Insurers (ABI) and Thatcham Research. It replaced the older A–D system with a clearer framework. Categories A and B are permanent total losses. Categories S and N can be repaired and returned to the road.
Category A — Crush Only
The most severe category. A Cat A vehicle must be crushed in its entirety — no components or parts may be removed and reused on a road vehicle. This category is reserved for vehicles that have suffered catastrophic damage:
- ▸Complete fire damage that has compromised the entire vehicle structure
- ▸Severe flood damage where all electrical and mechanical systems are beyond salvage
- ▸Extreme crush damage from a high-speed collision
- ▸Vehicles that have been deliberately destroyed
Can it return to the road? No — ever. If a Cat A vehicle appears for sale or on the road, it is fraud. The identity is permanently retired from the national database.
Category B — Break for Parts
The body shell of a Cat B vehicle must be destroyed, but mechanical and electrical components can be removed and reused in other vehicles. Engines, gearboxes, suspension components, interior trim, and electronics may be salvaged and sold.
- ▸Typical Cat B damage: severe frontal or rear structural damage where the shell is beyond economic repair
- ▸The scrap value of parts often exceeds the cost of a full rebuild
- ▸Legitimate salvage dealers purchase Cat B vehicles specifically to break for parts
- ▸Cat B parts can be fitted to other vehicles legally — only the shell must be destroyed
Can it return to the road? No. The body shell must be crushed. Any vehicle assembled on a Cat B shell and put on the road is illegal.
Category S — Structural Damage Repaired
A Cat S vehicle suffered structural damage — affecting the chassis, pillars, crumple zones, or sill structures — but has been repaired and returned to the road. The vehicle carries a permanent Cat S marker in its history. It must pass an MOT to return to the road after repair.
Category S replaced Category C in October 2017. Older vehicles may show Cat C — treat it identically to Cat S.
Can it return to the road? Yes, after proper structural repair and a passed MOT. Value is typically reduced by 20–40%.
Category N — Non-Structural Damage Repaired
A Cat N vehicle suffered damage that did not affect its structural integrity — typically cosmetic damage, electrical faults, airbag deployment, or mechanical damage that made repair uneconomical relative to the value. It has been repaired and returned to the road.
Category N replaced Category D in October 2017. Older Cat D vehicles should be treated identically to Cat N.
Can it return to the road? Yes. No structural repair is required. Value impact is typically 10–25% below clean equivalent.
Summary Comparison Table
| Category | Damage Type | Return to Road | Value Impact |
|---|---|---|---|
| Cat A | Total loss — crush only | Never | Total loss |
| Cat B | Shell destroyed — parts salvageable | Never | Total loss |
| Cat S | Structural damage — repaired | Yes, after MOT | 20–40% discount |
| Cat N | Non-structural damage — repaired | Yes | 10–25% discount |
Where Write-Off Data Is Held
Write-off categories are recorded by insurers on the MIAFTR register (Motor Insurance Anti-Fraud and Theft Register), maintained by Thatcham Research. The DVLA does not hold this information — it will not appear on a free government check. The data is accessible through licensed providers like VEHIXA, which queries Experian and Thatcham records.
This is why a free DVLA check is insufficient before buying a used car. The write-off status is the piece of information most likely to significantly affect what you should pay — and it is completely absent from free data.
Frequently Asked Questions
What are the car write-off categories in the UK?
The UK uses four insurance write-off categories: Category A (total loss — must be crushed, no parts reused on road), Category B (body shell destroyed, mechanical parts may be salvaged, cannot return to road), Category S (structural damage, repaired and returned to road), and Category N (non-structural damage, repaired and returned to road). Cat A and B are permanent total losses; Cat S and N can legally return to the road after repair.
What is a Category A write-off?
A Category A write-off is the most severe classification. The vehicle has suffered damage so severe — typically fire damage, total crush, or flood damage — that it must be crushed in its entirety. No parts from a Cat A vehicle may be reused on the road. The vehicle's identity is permanently retired. If a vehicle registered as Cat A ever appears for sale, it is either fraud or an error — do not buy it.
Can I buy and fix a Cat B car?
You can purchase a Cat B vehicle for parts, but the body shell must be destroyed. You cannot repair a Cat B vehicle and return it to the road — this is illegal. Some people buy Cat B vehicles for mechanical parts or for race and track-day use on private land, where road registration is not required. Never buy a Cat B car if you expect to drive it on public roads.
What happened to Category C and Category D?
Category C and Category D were replaced in October 2017 by Category S and Category N respectively. Cat C (now Cat S) involved structural damage that could be repaired. Cat D (now Cat N) involved non-structural damage. Vehicles written off before October 2017 may still show Cat C or Cat D in their history — treat Cat C as equivalent to Cat S, and Cat D as equivalent to Cat N.
Does a write-off category appear on the V5C?
No. The write-off category is not recorded on the V5C logbook. The DVLA does not hold insurance write-off data. Write-off categories are held by Thatcham Research on the MIAFTR register and by Experian. To find out if a vehicle has a write-off marker, you need a vehicle history check from a licensed data provider such as VEHIXA.
Check Any Vehicle for Write-Off Status
A VEHIXA full report queries Experian and MIAFTR to reveal Cat A, B, S, or N status — essential information before any used car purchase.
Check Write-Off Category