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How to check if a UK car is a write-off (Cat S, N, B, A)

Around 8% of used cars on the UK market have been written off at some point. Most aren't disclosed by the seller. If you buy a write-off without knowing, you'll lose £1-£5k when you come to sell. Here's how to check before you commit — for free and for £20.

SB Written by Salah Baaziz · Updated · Editorial standards

The 4 UK write-off categories explained

Cat A — Scrap only. Cannot legally return to the road. If you see this, walk away — something is criminally wrong.

Cat B — Body shell only. Cannot return to the road as a whole car. Parts can be sold; the body shell must be crushed.

Cat S — Structural damage. Can be repaired and returned to the road. Resale value affected. ABI introduced this in 2017 (formerly Cat C).

Cat N — Non-structural damage. Cosmetic or non-essential damage. Can be repaired and re-registered. Lowest impact on value (formerly Cat D).

How to do a free write-off check

1. Free DVLA Vehicle Enquiry — gov.uk/check-vehicle-information. Doesn't directly show write-off but shows make/model/colour vs the V5C. Mismatches = red flag.

2. MOT History — gov.uk/check-mot-history. Long gap in MOT history = car off the road, often after a write-off.

3. Use AutoAlpha's reg check tool — /tools/reg-check combines DVLA data into one quick view.

None of these will explicitly show 'write-off' — for that you need a paid check.

Paid HPI check — what it shows and what to pay

£20-£30 for a full HPI / RAC / Experian AutoCheck. Worth every penny. Shows:

• Write-off category (S, N, etc.)
• Outstanding finance (so you don't buy a car still owned by a finance company)
• Stolen markers
• Mileage history checks
• VIN/V5C mismatch flags
• Previous keepers count

Do this BEFORE you put a deposit down. Cancel the viewing if anything comes up.

Is a Cat S or Cat N car worth buying?

Cat N (cosmetic) — sometimes. If repair is documented and certified, and the price reflects the category, can be good value (15-25% discount vs equivalent).

Cat S (structural) — rarely. Even with documented repair, resale is brutal and insurance is harder. Only consider if the discount is 30-40%+ vs market.

Cat A or B — never.

If you're going to buy a Cat S/N car, get a professional inspection (£200) by an independent engineer — not just an MOT garage.

Red flags that suggest undisclosed write-off

Inconsistent panel gaps — front and rear corners are common impact zones.

Paint depth measurements vary across panels — Halfords sells a £25 gauge. Useful tool.

Overspray on interior trim or under-bonnet — sign of bodywork.

New replacement parts (radiator, headlights) on a high-mileage car.

VIN plates loose or recently disturbed.

Price significantly below market for the spec — see how to find genuine bargains for the legitimate version of this.

Frequently asked questions

Does a Cat S car have to be disclosed when sold?+
Yes — sellers must disclose write-off category. Failure to do so is fraud under the Consumer Rights Act. In practice, many private sellers don't disclose; always run an HPI check.
Can I insure a Cat S car?+
Yes but premiums are typically 15-30% higher and fewer insurers will cover them. Get an insurance quote BEFORE you buy a Cat S car.
How much less is a Cat S car worth?+
Roughly 20-30% less than the equivalent non-write-off. Cat N: 10-20% less. The discount varies by make/model and repair quality.
Can a car move between write-off categories?+
No — once categorised, the marker stays. Some pre-2017 Cat C cars are now functionally equivalent to Cat S; pre-2017 Cat D is functionally equivalent to Cat N.
What about "unrecorded damage" — not on HPI?+
Some self-repaired or repaired-without-insurance-claim damage won't show on HPI. This is why a physical inspection (or paid pre-purchase inspection) matters even after a clean HPI.