Cat A and Cat B: the two you must never buy
Category A means the entire vehicle must be crushed, with no parts salvaged. Category B means the body shell must be destroyed, though some parts may be reused. Neither should ever return to the road, and a car advertised for sale carrying either marker is a serious warning sign.
Updated 14 October 2026
Category A: scrap only
The most severe classification there is. The whole vehicle must be crushed. Not one component may be removed and sold on, not a wing mirror, not a seat.
Cars reach Cat A through catastrophic fire, severe flooding, or damage so extensive that nothing on them can be trusted.
Category B: break for parts, destroy the shell
The body shell must be crushed and can never go back on the road. Undamaged components (engine, gearbox, doors, electronics) may legally be removed and sold as parts.
That parts trade is legitimate. The shell returning to the road is not.
If a car you are looking at shows Cat A or Cat B
Walk away, and do not pay a deposit.
A Cat A or Cat B car being advertised means one of three things: the seller does not know, the record is being misrepresented, or the car has been illegally rebuilt, sometimes by welding two halves of different cars together, which is exactly as dangerous as it sounds.
It may also be a cut-and-shut using a stolen car’s identity, in which case you would have no legal title to it however much you paid, and it could be seized.
You can report it to your local police force and to the DVLA. You are under no obligation to explain yourself to the seller first.
How a Cat B ends up advertised anyway
The parts trade is the loophole. A Cat B car is legally sold to a dismantler, who may resell its components. What sometimes happens instead is that the shell is quietly repaired and sold on with its original registration, because the paperwork looks ordinary and nothing about the car announces itself.
The other route is a cut-and-shut: the front of one car welded to the back of another, usually carrying the identity of whichever half had the cleaner history. These fail catastrophically in an impact because the weld is not where the manufacturer put one, and the crumple structure no longer behaves as designed.
Neither is something you can see on a forecourt. Fresh underseal, mismatched panel gaps and a suspiciously tidy engine bay on an otherwise scruffy car are worth noticing, but the record is what actually tells you.
What it costs if you get this wrong
Your insurance may be void. Insurers do not cover vehicles that should not be on the road, and discovering that after a claim is the worst possible moment.
The car has no resale value. Nobody who checks will buy it, and you would be committing an offence to sell it without disclosing the category.
It may be seized. If the identity belongs to a stolen vehicle, the car goes and you have no claim on it.
And it may not protect you in a crash, which is the part that matters more than any of the above.
How these markers are found
Write-off categories are recorded on the insurance industry’s register at the point the insurer settles the claim. They stay there permanently, whatever subsequently happens to the car.
A vehicle history check reads that register directly. It is the only reliable way to see a Cat A or Cat B marker: nothing about the car itself will tell you, and that is rather the point of somebody rebuilding one.
An Odomint Check shows the category, the date it was recorded and the insurer who recorded it, alongside the full MOT history free. A car that was written off and then passed an MOT three months later under the same registration is a conversation worth having before any money changes hands.
Common questions
Is it illegal to sell a Cat B car?
Selling the salvageable parts is legal. Returning the body shell to the road is not, and a Cat B vehicle advertised as a roadworthy car should be treated as a serious warning sign.
Can a Cat A or Cat B car be repaired and re-registered?
No. Neither may lawfully return to the road. Any car on sale carrying one of these markers has either been misrepresented or illegally rebuilt.
What should I do if I have already bought one?
Stop driving it, contact your insurer (the policy may be void) and take legal advice. Report it to the police and the DVLA. You may have rights against the seller under the Consumer Rights Act.
Check any car before you buy it
MOT history, every advisory and the full mileage record are free for any UK registration. An Odomint Check adds outstanding finance, insurance write-offs, stolen markers and salvage history, with a £10,000 data guarantee.