Cat C, Cat D, Cat S, Cat N: what each really means for your purchase
UK insurance write-off categories without the jargon: which ones are safe to buy, how the discount typically works, and what you need on the paperwork before you sign.
Written off, not written off for you. Know the category, know the risk.
- Know the factsFour current categories, two legacy ones, one permanent marker.
- Understand the discount20–40% off clean equivalents, scaled by severity.
- Get the paperworkThree documents on the table before any deposit.
- Spot the bad onesAuction-flipped Cat S and flood-damaged Cat N.
- Price the riskResale, finance and insurance all move with the marker.
Why categories exist at all
Roughly one in eight used cars on the UK market has been written off at some point. Most are still perfectly road-legal.
When you crash a car, the insurer does not have to repair it. They can decide that repairing it costs more than the car is worth, pay you the market value, take ownership of the wreck and dispose of it. That is a write-off. Once written off, the car goes through the Salvage Code scheme run jointly by insurers and the Association of British Insurers, which records how badly damaged it was and whether it should ever be driven on a public road again.
The category is permanent. It is recorded on the V5C and against the registration on national databases. Every future buyer, and every future history check, will see it.
The current categories (post-October 2017)
In October 2017 the salvage code switched from a damage-cost basis (A/B/C/D) to a damage-type basis (A/B/S/N). The new system asks what kind of damage, not just how much it cost to fix.
- ACat AScrap only
So badly damaged it must be crushed in its entirety. Not a single part can be recovered for reuse.
Never road-legal
It is a legal offence to put one back on the road. Walk away.
- BCat BParts recoverable, body crushed
The body shell is unsafe and must be crushed, but mechanical and trim parts can be removed and reused as donor parts.
Never road-legal
If someone is selling you one as a car, it has been illegally rebuilt around a crushed shell.
- SCat SStructural damage, repairable
Damage to a structural component (chassis, A/B/C-pillars, sub-frame, suspension mounts or bulkhead) that the insurer judged can be safely repaired by a competent body shop.
Road-legal after repair
The salvage operator notifies the DVLA and the car must be re-registered. Treat with caution.
- NCat NNon-structural damage, repairable
Cosmetic or non-structural mechanical damage: bumpers, panels, lights, electronics, air-con, even an engine swap. Repairable without touching the safety cell.
Road-legal after repair
The lightest modern category, but not automatically a bargain. Some are flood cars with expensive electronics replaced.
The legacy categories (pre-October 2017)
Cars written off before October 2017 keep the old Cat C and Cat D markers. There is no automatic re-classification.
Cat C (legacy) ≈ Cat S today
Repair cost would exceed the car's pre-accident value, but it can be repaired. In practice, structural damage was almost always involved.
Treat like Cat SCat D (legacy) ≈ Cat N today
Repair cost was less than the pre-accident value, but the insurer chose to pay out instead, often faster than waiting for parts. Typically cosmetic damage.
Treat like Cat N
The category never changes. A 2014 car marked Cat C is still Cat C today, and the listing will use whichever category was current when the write-off was recorded.
What changes after a write-off
A repaired Cat S, N, C or D vehicle is road-legal if:
- 1Independently inspected and certified as safely repaired.
- 2The repair documented.
- 3The V5C re-registered through the DVLA.
- 4A current MOT.
Three things change permanently:
- The V5C carries the markerThe car can never be sold as clean. Every future history check will show it.
- Resale value drops 20–40%Roughly proportional to category severity, and it compounds if you ever total the car yourself.
- Insurance can cost 10–30% moreSome specialists price it as a clean car; mass-market insurers tend to load the premium. Quote both before you buy.
What discounts to expect
Written-off cars typically sell at 20–40% below clean equivalents, roughly proportional to category severity.
- Cat Nabout 15–25% off
- Cat S25–40% off
- Cat C (legacy)up to 40% off
- Cat D (legacy)15–25% off
Bigger risk means a bigger discount, but a discount without the paperwork is not a discount. You are buying an unknown.
Paperwork you must get
If the listing mentions a category, or a history check turns one up, you need three documents on the table before a deposit.
The full repair invoice
What was done, by whom, and what parts were used. “Bodyshop repair £4,200” is not enough; you want item-level detail.
An independent engineer's report
Most insurers require an SAE-engineer inspection before insuring a Cat S car for a new owner. If the seller has none, pay for one yourself before contracting, around £150.
A V5C in the seller's name
Page 1 lists any salvage codes. If the V5C is not in their name yet, or does not show the marker, the paperwork chain is broken.
If any of those three are missing, the discount you are being offered is not actually a discount.
Finance and insurance implications
Four things to factor into the budget before you commit.
HP and PCP can be refused on Cat S
Lenders treat the lower residual value as a risk. Cat N is usually fine; Cat S depends on the lender. Always pre-quote.
Comprehensive cover is sometimes declined
Most insurers will quote, but a few decline. A fleet underwriter may class a Cat S vehicle as ineligible regardless of repair quality.
Total-loss payouts are reduced
If you crash it next year, the payout reflects the category-discounted market value, not the clean equivalent.
Warranties are often voided
Cat N usually does not void a manufacturer warranty; Cat S almost always does. A car still under warranty is not worth a 30% Cat S discount once you lose the cover.
When it is genuinely a bargain
- A three-year-old car with a Cat N from a minor front-end shunt, repaired by a manufacturer-approved bodyshop with documented invoices, sold at 18% off clean book.
- A high-spec variant otherwise out of budget, where the category drop is what brings it into range.
- A model with very strong mechanical reliability where the cosmetic or electronic repairs were professionally done.
When it is catastrophic
- Auction-flipped Cat S vehicles with no inspection report, repaired by a back-street body shop, finished in mismatched paint.
- Flood-damaged Cat N vehicles where the electrics rot from the inside out; they present perfectly for three months and start failing in the fourth.
A practical decision framework
When a category appears in the history check.
- Cat A or Cat BNever, under any circumstances, regardless of price.
- Cat S (or legacy Cat C)Only with an engineer's report, manufacturer-approved bodyshop invoices, and a discount that reflects the resale and finance risk. Treat 25% off as a starting position, not a final price.
- Cat N (or legacy Cat D)Generally fine if the repair is documented. Aim for 15–20% off equivalent clean, less if the repair was minor and verified.
- No categoryWhat most of the market is. No special process needed beyond a normal pre-purchase inspection.
The category is a signal, not a verdict. Buyers who walk away from every marker miss real bargains; buyers who ignore it entirely overpay for hidden risk. Demand evidence proportional to the severity, and factor the resale and insurance implications into your offer.
Buying a write-off? Do it with confidence.
The damage category is extracted from each listing during the initial scan and surfaced as a warning chip on the card, alongside the value score. Damage history is scored on a fixed scale (clean 100, Cat N 50, unstated 45, Cat S 30, with the legacy codes scoring as their modern equivalents) and carries 10% of the overall score, so a Cat S gives up about seven points against an identical clean car. Not a veto: a big enough discount can still out-score a clean one, which is exactly the trade-off to think about.
- Write-off category flagged on the listing card
- Cat C and Cat D scored as the Cat S and Cat N they equal
- An unstated history never out-scores a disclosed repair
- Compare against clean equivalents side by side
