Category A and Category B are the write-offs you can never buy for the road. A Cat A car must be crushed in its entirety; a Cat B car's body shell must be crushed, though undamaged parts can be salvaged.
Neither may ever be re-registered or driven again, so a Cat A or B car advertised as a runner is a warning, not an opportunity.
What are Category A and B write-offs?
When an insurer writes a car off, it assigns one of four salvage categories. GOV.UK's official definitions split them cleanly: A and B "cannot be repaired", while S (structural damage) and N (non-structural) can be repaired and legally driven again.
The categories come from the insurance industry's Salvage Code of Practice, which replaced the old Cat C and Cat D with S and N from October 2017.
| Category | Damage | Parts reuse | Back on the road? |
|---|---|---|---|
| A | Beyond any safe use, often fire or severe crash | None: everything is crushed | Never |
| B | Body shell unsafe to repair | Undamaged parts may be salvaged | Never |
| S | Structural, professionally repairable | Car itself is repaired | Yes, once roadworthy |
| N | Non-structural (panels, electrics, trim) | Car itself is repaired | Yes, once roadworthy |
What's the difference between Cat A and Cat B?
The fate of the parts. Cat A is scrap only: the damage (often fire, flood or a catastrophic collision) is so complete that nothing can be safely reused, so the whole car is destroyed.
Cat B means the structure can't be trusted, so the shell is crushed, but an approved dismantler may remove sound components (an engine, a gearbox, doors) and sell them as used parts. For the car itself the outcome is identical: it is finished.
Can a Cat A or Cat B car ever go back on the road?
No. Both categories permanently end the vehicle's road life; the record follows the car, and DVLA will refuse to register a Cat B vehicle for the road. That is the whole point of the categories: an engineer judged the structure beyond safe repair, and no respray changes that judgement.
Can you buy a Cat B car for parts?
The parts, yes; the car, effectively no. Salvage from Cat B vehicles moves through licensed dismantlers, and buying a used engine or panel that started life on one is normal and legal.
What you can't legally do is put the vehicle itself back together and drive it. If you're offered a complete Cat B "project" as a future road car, the project is illegal from the start.
Why would a Cat A or B car be for sale as a runner?
Because something has gone wrong, and every explanation is bad:
- It was illegally rebuilt from a shell that should have been crushed.
- It's wearing a cloned identity borrowed from an innocent car of the same model.
- The seller is simply betting you won't run a check before the cash changes hands.
A rebuilt Cat B isn't a brave bargain; it's a car an insurer condemned, back on the road under a false story, uninsurable the moment the truth surfaces. Walk away, whatever the price.
How do you check a car's category before buying?
Write-off markers don't appear in the free DVLA data. They live on the insurance industry's register, so seeing the category itself takes a check that queries it, which is what our full history check does.
Our guide to checking if a car has been written off covers the detail, with a £5 history report alongside for the official record: spec, keepers, MOT history and the plate changes cloned cars rely on.
Match the VIN to the V5C too. And for the categories you can buy with your eyes open, our Cat N and Cat S guide explains how to weigh one up.