Car Insurance Write-Off Categories Explained

Car insurance write-off categories are the four codes UK insurers use to grade a damaged vehicle: Category A, Category B, Category S and Category N. The code records how badly a car is damaged and whether it can ever legally return to the road. Category A and B vehicles must be destroyed; Category S and N vehicles can be repaired and driven again if the work is done properly and they are roadworthy.

A vehicle is normally written off when the insurer decides repairing it costs more than it is worth, or the damage makes it unsafe to fix. At that point the insurer usually pays you the car’s current market value rather than funding the repair. The category then stays attached to the vehicle’s history for life, which matters if you later buy or sell it.

For most Free Price Compare buyers, who are typically in their late 40s or 50s and choosing comprehensive cover, the practical questions are simple: what does my category mean, can the car go back on the road, and will it affect my cover and premium. Those are answered below using the current GOV.UK and Association of British Insurers (ABI) definitions.

Last updated: October 2026

Written by the Free Price Compare editorial team | Reviewed October 2026

What do Cat A, B, S and N actually mean?

Cat A, B, S and N are the four UK insurance write-off categories that describe how badly a car is damaged and whether it can go back on the road. The system replaced the older C and D categories, which were retired in 2017. According to GOV.UK, in guidance updated on 2 October 2026, Category A means scrap only, Category B means break for salvageable parts, Category S means repairable structural damage, and Category N means repairable non-structural damage.

Category A and B are treated as an “actual loss”: the vehicle cannot or should not come back as a complete car. Category S and N are a “constructive loss”, meaning repair is physically possible but the insurer judged it uneconomical compared with the car’s value. The ABI applies these codes through its voluntary Salvage Code of Practice, which all ABI member motor insurers follow; the ABI updated that code in May 2025.

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Why would an insurer write off a car that looks fixable?

An insurer writes off a car when the cost of repairing it reaches a point where replacing it makes more financial sense, even if the repair bill looks lower than the payout. This is why a car with what seems like modest damage can still be declared a total loss. The decision is driven by the car’s current market value, the full repair estimate including parts, labour and a courtesy car, and whether the damage affects safety.

Some insurers use a repair-cost threshold of roughly 50% to 70% of a car’s market value as a trigger for writing it off, though this is an insurer-specific underwriting guide rather than an industry-wide rule. On an older or lower-value car, repairs reach that threshold quickly. That matters for Free Price Compare users: around 43-48% of our car insurance quotes are for a car valued between £1,000 and £5,000 (Free Price Compare data, Jan-Jun 2026), and lower-value cars are written off more readily because repair costs are a larger share of their worth.

When your car is written off, the insurer normally pays its market value at the time of the incident, minus any excess you owe. If you disagree with the valuation, you can challenge it with evidence of comparable cars for sale, and escalate to the FCA-regulated Financial Ombudsman Service if the dispute is not resolved.

How does the excess affect a write-off payout?

A car insurance excess is the fixed amount you agree to pay towards any claim before the insurer pays the rest, and it is deducted from your write-off payout. If your car is valued at £4,000 and your total excess is £500, you receive £3,500. Your excess is made up of a compulsory excess set by the insurer plus any voluntary excess you chose when buying the policy.

Choosing a higher voluntary excess lowers your premium but increases what you lose if the car is written off, so it is worth balancing the two. Our guide to how voluntary and compulsory excess work explains how to set a level that suits your car’s value. If the accident was not your fault, you may be able to recover the excess from the other driver’s insurer, as covered in our guide on paying excess when you are not at fault.

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Can a written-off car legally go back on the road?

A written-off car can legally return to the road only if it is a Category S or Category N vehicle that has been properly repaired and is roadworthy. Category A and Category B vehicles cannot, because GOV.UK requires Cat A cars to be crushed entirely and Cat B body shells to be destroyed. The DVLA will not re-register a Category A or B vehicle, so neither can ever carry a valid registration again.

For a repaired Cat S or Cat N car, there is no government-mandated re-inspection scheme in place for standard private cars, but the repairs must be done to a safe, roadworthy standard and the car needs a valid MOT if it is three years old or more. If you kept your own car after it was declared a total loss, you buy the salvage back from the insurer and are responsible for ensuring it is roadworthy before driving it.

What happens if I repair the car myself without a claim?

A car only receives a write-off category when an insurer records it as a total loss following a claim. If you have an accident and pay for the repairs yourself without involving your insurer, the car is not assigned a Cat S or Cat N marker, because no insurer has declared it a total loss. The category is created by the insurance process, not by the damage itself.

This is a common point of confusion. A privately repaired car carries no write-off marker, but any insurer-recorded total loss stays on the vehicle’s history permanently and will show on an HPI or history check.

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Should I buy a Cat S or Cat N car?

Buying a Cat S or Cat N car can save you money against the same model with a clean history, but it carries risks that are worth weighing carefully. A Category N car had non-structural damage, such as cosmetic panels, lights, electrics or interior trim, while a Category S car had structural damage to parts like the chassis or crumple zones that was repaired. Cat N damage is generally lower risk than Cat S, but “non-structural” does not guarantee the damage was minor.

Before buying a repaired write-off, get an independent inspection and a vehicle history check, ask for proof of who carried out the repairs, and confirm it has a valid MOT. Two practical points often catch buyers out: a written-off car typically sells for less than an equivalent clean car, and that lower resale value will apply again when you come to sell it.

• Commission an independent mechanical and bodywork inspection before committing.
• Run a history check to confirm the exact category and any outstanding finance.
• Ask for repair invoices and photographs of the damage and the work done.
• Confirm you can get cover and agree a valuation with an insurer before you buy.

Will a Cat S or Cat N car be harder to insure?

Insuring a repaired Cat S or Cat N car is possible with many providers, but availability, cover level and price are set by each insurer’s own underwriting, so there is no universal rule. Some insurers accept repaired write-offs readily; others decline them or ask for proof of roadworthy repairs. You must disclose the write-off history when you apply, even if the insurer does not ask directly, because failing to do so can invalidate your cover.

Because acceptance varies, comparing across a broad panel helps. Free Price Compare compares car insurance from a panel of 130+ insurers, which widens the chance of finding one that covers a repaired write-off at a workable price. Around 88-89% of our car insurance quotes are for comprehensive cover (Free Price Compare data, Jan-Jun 2026), and comprehensive is usually the sensible choice on a repaired car where you still want protection for damage to your own vehicle.

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What a write-off means if your car is on finance

If a financed car is written off, the insurer’s payout goes towards settling the outstanding finance first, and you keep anything left over. A problem arises when the market-value payout is less than the balance you still owe, leaving you in negative equity and liable for the shortfall. This is most common on PCP and hire purchase agreements in the early years, when depreciation outpaces how much of the loan you have repaid.

Guaranteed Asset Protection (GAP) insurance is designed to cover that gap between the insurer’s payout and the finance balance. If you drive a financed car, our guide on what happens when a car on finance is written off walks through the settlement order and your options. You should also tell the finance company promptly, as the car remains their asset until the agreement is cleared.

Does a write-off affect my no-claims bonus?

A no-claims bonus is the discount insurers give for each consecutive year you do not make a claim, and a write-off claim normally counts against it unless the accident was not your fault and your insurer recovers its costs in full. If you have protected no-claims bonus, an agreed number of claims will not reduce your discount, though it can still affect your overall premium at renewal.

A fault write-off typically resets or reduces your no-claims bonus, which raises future premiums. Around 16-19% of Free Price Compare car insurance quotes come from drivers with 20 or more years of no-claims bonus (Free Price Compare data, Jan-Jun 2026), and protecting that record is worth checking before you accept a settlement that logs the claim as fault.

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Information correct as of 16 October 2026. Prices, tariffs, policy details and providers change frequently, so please check the latest details before making a decision. This article is for general information only and does not constitute financial advice. Free Price Compare is authorised and regulated by the Financial Conduct Authority (FCA).