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Car Write-Off Categories Explained

A UK guide to insurance write-off categories A, B, S and N — what each one means, the old vs new system, and what to check before buying a written-off car.

By: John Clark Updated: 9 Apr 2026 Reading time: ~7 min
Car write-off categories explained: A, B, S and N categories for written-off vehicles in the UK

When a UK insurer decides a damaged vehicle isn't economically viable to repair under the policy, they "write it off" and assign a category. Since October 2017, the UK uses four categories: A, B, S and N. The category determines whether the vehicle can ever return to the road.

In this guide
  • The four UK write-off categories (A, B, S, N)
  • Old vs new category system
  • Should you buy a write-off?
  • How write-offs appear on a vehicle check
  • Frequently asked questions

The four UK write-off categories

Since October 2017, the Association of British Insurers (ABI) classifies written-off vehicles into four categories. The first two (A and B) mean the vehicle must never return to the road. The other two (S and N) mean the vehicle can be repaired and re-registered.

Category A — Scrap only

Category A is the most severe classification. The entire vehicle must be crushed — no parts can be salvaged or resold. This category is typically applied after extreme fire damage, severe flood damage, or catastrophic structural failure that makes every component unsafe. A Category A vehicle cannot be re-registered and should never appear for sale as a whole vehicle or as parts.

Category B — Break for parts

The body shell must be crushed, but salvageable parts (engine, gearbox, electronics, trim) can be removed and resold individually. Category B is used when the vehicle's structure is too damaged to repair safely, but some mechanical or cosmetic components remain usable. Like Category A, a Cat B vehicle cannot be re-registered as a whole vehicle and should never be offered for sale as a driveable car.

Category S — Structural damage, repairable

Previously known as "Category C" under the old system, Category S indicates the vehicle has sustained structural damage — to the chassis, crumple zones, pillars or other load-bearing elements — but can be professionally repaired and returned to the road. Before re-registration, a Cat S vehicle must pass a Vehicle Identity Check (VIC) or equivalent inspection to confirm it is roadworthy and its identity has not been altered. Category S is one of the most common write-off categories that buyers encounter on the used market.

Category N — Non-structural damage, repairable

Previously known as "Category D", Category N covers vehicles with non-structural damage — for example, body panels, bumpers, electronics, or engine and gearbox faults. The key distinction is that no structural or load-bearing components have been affected. A Cat N vehicle can be repaired and returned to the road without a mandatory re-inspection, although an independent inspection is strongly recommended before purchase. Category N is the most common write-off category overall, as even relatively minor damage can be uneconomical for an insurer to repair under the terms of the policy.

Category Damage type Can return to road? Re-inspection required?
Cat A Total loss — scrap only No N/A
Cat B Break for parts only No N/A
Cat S Structural damage (repairable) Yes Yes (DVLA re-registration)
Cat N Non-structural damage (repairable) Yes No (but recommended)

Old vs new category system

Before October 2017, the UK used Categories A, B, C and D. The system was updated to make the classification clearer and more directly linked to the type of damage rather than just the economics of repair.

1
Categories A and B stayed the same
Cat A (scrap) and Cat B (break) were carried over with no meaningful change in definition.
2
Category C became Category S (Structural)
The old Cat C was based on repair cost exceeding the vehicle's value. The new Cat S specifically identifies structural damage, regardless of cost.
3
Category D became Category N (Non-structural)
The old Cat D covered vehicles where repair costs were less than market value but uneconomical for the insurer. Cat N now specifically means non-structural damage only.
4
The key difference: damage type, not just cost
The old system categorised largely based on the economics of repair (cost vs value). The new system distinguishes between structural and non-structural damage, which is far more useful for buyers assessing safety risk.

Should you buy a write-off?

Category S and N vehicles are legal to buy and sell in the UK, and they can represent good value — typically 20–40% cheaper than equivalent cars with no write-off history. However, the savings come with real risks that you need to manage carefully.

Potential benefits

  • Significant price reduction compared to equivalent non-written-off vehicles
  • A well-repaired Cat S or Cat N car can be perfectly safe and reliable
  • If you plan to keep the car long-term, the lower resale value matters less

Key risks

Repair quality varies hugely
Some repairs are carried out to a high standard by specialists; others are bodged cheaply with no regard for safety. Without inspecting the work, you have no way to tell.
Resale value is permanently affected
A write-off marker stays on the vehicle's record permanently. When you come to sell, most buyers will want a discount, and trade-in values will be lower.
Insurance can be more expensive or harder to get
Some insurers charge higher premiums for previously written-off vehicles, and a few may refuse to cover them entirely. Always check insurability before you buy.

Essential checks before buying a write-off

1
Get an independent mechanical inspection
Pay for a professional inspection from an independent engineer or a service like the AA or RAC. This is not optional — it is the single most important step.
2
Check repair invoices and photographic evidence
Ask the seller for full documentation of the repair work: invoices, receipts for parts, and before/after photographs. A reputable repairer will have these on file.
3
Verify the VIN has not changed
Check the VIN on the vehicle against the V5C logbook and the vehicle history report. Criminals sometimes swap identities between written-off and stolen vehicles (known as "ringing").
4
Check MOT history for post-repair advisories
Use the DVSA MOT history service to look for advisories or failures after the write-off date. Persistent issues with suspension, alignment or structural components are red flags.
Category A and B vehicles should never be for sale as complete vehicles

If you see a Cat A or Cat B car advertised as a whole, driveable vehicle, walk away immediately. It is illegal to put these back on the road, and selling them as complete cars is a serious red flag for fraud.

How write-offs appear on a vehicle check

Write-off markers on a vehicle history report come from the Motor Insurance Anti-Fraud and Theft Register (MIAFTR) database, which is maintained by the insurance industry. When an insurer writes off a vehicle, the record is added to this database and becomes visible on vehicle check reports.

A typical vehicle history report will show the write-off category (A, B, S or N), the date the write-off was recorded, and sometimes the insurer involved. This information is permanent — even after a Cat S or Cat N vehicle has been repaired and returned to the road, the write-off marker remains on its record.

Important caveat: not all damage is reported. If a vehicle was damaged and repaired privately without an insurance claim being made, there will be no write-off marker on the record. This is why a clean vehicle history report should always be combined with a physical inspection — the absence of a marker does not guarantee the car has never been damaged.

FAQs

Can I insure a Cat S or Cat N car?

Yes, most UK insurers will cover Cat S and Cat N vehicles, but premiums may be higher than for an equivalent car with no write-off history. A small number of insurers refuse to cover previously written-off cars, so it is worth getting insurance quotes before you commit to buying.

Does a write-off marker ever get removed?

No. Once a vehicle has been recorded as a write-off on the MIAFTR database, the marker is permanent. Even if the car has been professionally repaired and is in excellent condition, the write-off history will always appear on vehicle check reports.

What is the difference between Cat S and Cat N?

Category S means the vehicle has structural damage (chassis, crumple zones, pillars), while Category N means the damage is non-structural (panels, bumpers, electrics, mechanical). Both can be repaired and returned to the road, but Cat S vehicles must pass a re-inspection before re-registration.

How much cheaper are written-off cars?

Cat S and Cat N cars are typically 20–40% cheaper than equivalent vehicles with no write-off history. The exact discount depends on the age, make, model and the severity of the original damage. The discount tends to be larger for Cat S (structural) than Cat N (non-structural).

Can I check if a car is a write-off for free?

Basic vehicle checks may not include write-off data. A comprehensive vehicle history report, such as those from CarCheckReport, queries the MIAFTR database and will show whether a write-off marker exists, along with the category and date. This is one of the most important checks you can run before buying a used car.

Disclaimer: This content is for informational purposes. Always verify with official documents and professional checks before purchase.