Cat S and Cat N Cars Explained: A UK Buyer's Guide to Write-Offs

A spotless used car can still carry a past that changes what it is worth. If an insurer has written it off, it is given a salvage category that follows it for life. This guide explains each category, what replaced Cat C and Cat D, how a write-off affects insurance, finance and value, and how to find out whether a car has one.

What "written off" actually means

When a car is badly damaged, the insurer decides whether to repair it or settle the claim as a total loss. If it settles, the vehicle becomes salvage and is categorised under the Association of British Insurers (ABI) Code of Practice for the Categorisation of Motorised Vehicle Salvage, currently version 12, dated May 2025.

The assessment is made by an "Appropriately Qualified Person" with vehicle repair training and a current competency assessment. Every categorised vehicle is logged on MIAFTR, the insurance industry's total-loss register, and the Code notes that data agencies use this information for vehicle check services. That is why a history check can reveal a write-off a seller has not mentioned.

The four categories: A, B, S and N

Category A – scrap

The vehicle has been judged unsuitable for, or beyond, repair. After depollution and removal of recyclable materials, the whole car is crushed, including the part of the frame that carries the VIN. It can never legally return to the road, and GOV.UK confirms the entire vehicle has to be crushed.

Category B – break

The structural frame is beyond repair and must be crushed, but some parts can be salvaged and reused. The shell carrying the VIN is destroyed, so the vehicle itself cannot be put back on the road. Be very wary of anyone offering a "Cat B" car for sale as a runner.

Category S – repairable, structural damage

The structural frame or chassis has been damaged and needs realignment or replacement, but the car can be repaired. The Code defines damage as structural when any structural element needs to be realigned to its original dimensions or replaced; purely cosmetic work does not count. Once properly repaired to a roadworthy condition, a Cat S car can be used again.

Category N – repairable, non-structural damage

The damage does not affect the structure, but that does not mean it was trivial. The Code notes that safety-critical parts such as brakes, steering or airbags may still need replacing. Like Cat S, a Cat N car can be driven again once repaired to a roadworthy standard.

What changed from Cat C and Cat D

Before 1 October 2017, repairable write-offs were Category C or D. Announcing the change, the ABI said modern cars are more complex to repair safely and that the new code focuses on the vehicle's condition rather than repair cost. Broadly, Cat S replaced Cat C and Cat N replaced Cat D, but the basis differs: the old labels were tied to repair economics, the new ones to the type of damage.

Cars categorised before October 2017 were not reassessed, so you may still see Cat C or Cat D adverts. Treat them with the same caution as Cat S and Cat N respectively.

What happens to the paperwork

GOV.UK sets out the owner's duties when a car is written off:

• Tell DVLA. The owner must tell DVLA the vehicle has been written off. You can be fined up to £1,000 if you do not.
• Hand over the log book. Normally you send the V5C to your insurer but keep the yellow "sell, transfer or part-exchange" section.
• Keeping a Cat S car. If you buy back a Cat S vehicle from your insurer, you send the complete log book to the insurer and apply for a free duplicate using form V62.
• Keeping a Cat N car. You can keep your existing log book.

GOV.UK says DVLA will record the vehicle's category in the log book. However, motoring guides such as What Car? say a Cat N status does not appear on the logbook, and older or replacement documents can be inconsistent, so never rely on the V5C alone to tell you whether a car has been written off.

Insurance and finance implications

Insurance

You must tell your insurer about a write-off history. If you do not, a claim could be rejected or your policy treated as invalid. Some insurers charge more for Cat S or Cat N cars, some want an engineer's report, and some refuse cover. Get a quote before you buy.

Remember that a future total-loss payout is based on market value, which already reflects the write-off. Overpay for a repaired car and you will not recover the difference in a claim.

Finance

Lenders treat the car as security, so some may decline write-off vehicles or lend less against them. Check with your lender before agreeing a price. Separately, a history check shows whether finance is still outstanding on the car, which is just as important.

How a write-off category affects value

There is no official discount for a Cat S or Cat N car, and we found no credible published source for a reliable percentage, so be sceptical of fixed figures. What we can explain is why these cars are worth less:

• Fewer buyers. Many private buyers and dealers avoid write-offs, and lower demand means lower prices.
• The label is permanent. You buy at a discount and will sell at one too.
• Insurance and finance friction. Higher premiums, refused cover or cautious lenders reduce what buyers can pay.
• Repair uncertainty. Buyers price in the risk of a poor repair. Structural damage (Cat S) usually worries them more than non-structural (Cat N).
• Warranty. Cover may not apply to a written-off car, so future faults are on you.
• Evidence. Damage photos, an itemised invoice from a reputable repairer and an independent inspection narrow the gap.

Start with a valuation of a comparable clean-history car on moValue, then adjust for the category, the type of damage and the repair evidence.

What to check before buying a Cat S or Cat N car

1. Get the category in writing, with the write-off date. The Motor Ombudsman notes that a dealer selling an undisclosed Cat S or N car may breach the Consumer Rights Act 2015.
2. Ask what happened, with photos of the damage before repair.
3. Ask for the repair invoice listing parts and labour. Structural repairs should come from a competent bodyshop.
4. Get an independent inspection rather than relying on the seller.
5. Check the MOT history on GOV.UK for gaps, failures and mileage anomalies.
6. Match the VIN on the car to the V5C, and check the V5C is genuine.
7. Get an insurance quote first.
8. Run a full history check to confirm the category, outstanding finance and theft records.

How to find out if a car has been written off

The DVLA vehicle enquiry service shows tax and MOT status, engine size and the date the last V5C was issued, but not write-off status. The MOT history service shows results and mileage, not insurance categories. Write-off records sit on MIAFTR, which feeds commercial history checks, so a paid check is the most reliable route. Also watch for:

• A recent V5C issue date with no obvious reason.
• A long MOT gap followed by a sudden return to the road.
• A price well below similar cars with no explanation.
• A seller reluctant to show the V5C or meet at the registered address.