Cat A and Cat B are the two most severe insurance write-off categories in the UK, and neither is a repairable car. Cat A means the whole vehicle is to be scrapped. Cat B means the body shell is to be crushed, but some parts can be taken off and reused. A car in either category should not be repaired and put back on the road, so if a history check shows an A or B marker on a car you are being offered to drive away, treat it as a serious red flag.
- Cat A means scrap only. The vehicle is crushed in its entirety and no parts are reused.
- Cat B means break for parts. The shell must be crushed, but undamaged parts can be removed and reused, with firm limits on safety parts.
- Neither can return to the road. That is the key difference from Cat S (structural damage) and Cat N (non-structural damage), which can be repaired.
- "Cat B breaker" means a car that can only be dismantled. It is a dismantler's category, not a car for a driver.
- A road-going car showing Cat A or Cat B is a warning sign. It could be a rebuilt shell, a cloned identity or a data error. Do not pay until you know which.
What Cat A Means
Category A is for vehicles an insurance assessor has judged unsuitable for repair, with no parts worth reusing. The whole vehicle is to be crushed. Nothing is meant to be taken off it and sold for reuse, which is the main difference from Cat B.
The categories come from the Association of British Insurers (ABI) salvage code. The A, B, S and N system started on 1 October 2017, and the latest version of the code is dated May 2025. Insurers use it when they write a vehicle off, and the result is recorded against the vehicle.
In practice, a Cat A car should end its life at an authorised treatment facility. It should not appear on a forecourt, on a classified site or at a salvage auction as something you can buy and drive. If you want the full background on how all four modern categories work, see our guide to write-off categories explained.
What Cat B Means
Category B is the second most severe. The vehicle cannot be repaired and put back on the road, and the body shell must be crushed. The difference from Cat A is that components can be removed first, as long as they are suitable for reuse, and sold on.
That makes Cat B the category of the breaker's yard. A car may have been in a front or side impact, but its engine, gearbox, wheels, glass, lights and interior trim were fine. The insurer cannot justify or allow a repair, so the car goes to a dismantler who strips what is reusable and sends the shell to be crushed.
What does "Cat B breaker" mean?
"Cat B breaker" describes a Cat B vehicle that is sold to be broken up for parts. You will see it in auction listings and trade conversations. It tells a dismantler what they are buying: a car that can be stripped, not one that can be repaired and registered. It is not a sign that a car is a bargain for private use.
What parts can be reused from a Cat B car?
The reasoning is simple: the body shell carries the structure and crash protection of the car, so it is crushed. Other parts can be reused if they are undamaged and their future working can be confirmed. Bolt-on panels and doors can be taken off too, but no welded or bonded section of the shell can be.
The ABI code sets firm limits. Airbags, seat belts, seat belt pre-tensioners, stalks and buckles must never be re-sold or reused from a written-off car. Other safety parts, such as brakes or suspension, can only be reused if they have been inspected and found undamaged. If you buy a used part, ask the breaker which car it came from and what checks were done on it.
Can a Cat A or Cat B Car Go Back on the Road?
No. The categories exist to stop it. A Cat A or Cat B vehicle is meant to be destroyed or have its shell destroyed, and the record of that destruction is how the vehicle is taken out of circulation.
For a buyer, the practical meaning is this: there should be no legitimate road-going car with a Cat A or Cat B marker. If you are viewing one, one of the following is probably true.
- The car has taken a written-off car's identity. Criminals buy a wreck for its registration and VIN, then put them on a similar car, often a stolen one. This is called ringing. The write-off is real, but it belongs to the original car. Our guide to number plate cloning explains how to spot it.
- The car was rebuilt from a shell that should have been crushed. Someone bought the wreck, repaired it and tried to put it back on the road. That is the scenario the category system is meant to prevent, and the repair quality is unknown. Our guide to salvage auction cars and history checks explains how write-offs end up on the market.
- There is a data error. Rare, but possible. It should be resolved with proof, not on a seller's word.
None of those is something to take a chance on. The car may be unsafe, the identity may not match the paperwork, and you could lose the car and your money if it is traced.
Cat A and Cat B vs Cat S and Cat N
The sharpest line in the system sits between B and S. Everything above it is scrap or break. Everything below it can be repaired and used again once it is roadworthy.
| Category | Meaning | Repairable? | Parts reuse |
|---|---|---|---|
| Cat A | Scrap only | No, crush the whole vehicle | None |
| Cat B | Break | No, crush the shell | Undamaged parts, never airbags or seat belts |
| Cat S | Structural damage | Yes, after a proper repair | Vehicle continues as a car |
| Cat N | Non-structural damage | Yes | Vehicle continues as a car |
| Cat C (pre-Oct 2017) | Repair cost exceeded value | Yes | Old cost-based category |
| Cat D (pre-Oct 2017) | Repairable, insurer chose not to repair | Yes | Old cost-based category |
The old C and D categories were replaced by S and N on 1 October 2017. A and B kept their letters, but they are now decided by the condition of the car rather than repair cost. Our guides to Cat D and Cat C and Cat S cover the repairable categories in full.
Cat A and B vs "Scrapped" Markers
Buyers sometimes confuse a write-off category with a scrapped marker. They are related, but they are not the same thing.
- A write-off category is an insurer's classification of how a vehicle was assessed after damage.
- A scrapped or destroyed marker is a DVLA record that the vehicle has been scrapped, which ends the vehicle's life as a registered road vehicle.
A Cat A or Cat B vehicle is expected to be destroyed or have its shell destroyed, so it may be followed by a scrapped record. If a car shows Cat A or B and a scrapped status, and is still being advertised for sale, that is a particularly serious mismatch. If it shows Cat A or B and has been taxed or had an MOT since, treat that as a serious warning. The V5C for a Cat A or B car should never be reissued, so a car with that history being used on the road needs an explanation backed by documents, and in most cases you should walk away.
Insurance and Cat A or Cat B
You cannot insure a Cat A or Cat B vehicle to drive in the ordinary way, because it should not be on the road. A normal motor policy depends on a vehicle that is properly registered and roadworthy, and these are neither.
If you are asked for insurance on a car that turns out to carry A or B on its history, do not hide it. Telling an insurer something untrue about a vehicle's history can lead to a claim being refused or a policy cancelled, and driving without valid cover is an offence. For the repairable categories, see our guide to insuring a Cat S car.
How to Check a Car's Category by Registration
The free DVLA vehicle enquiry confirms basic details such as tax and MOT status. It is useful, but it does not show write-off categories, so a clean enquiry result does not tell you a car was never written off.
To see a write-off record, you need a history check that draws on insurer write-off records. Carhealth uses Experian data for write-off, finance and stolen records, and the report covers 23 checks in one report. In the report, look for:
- whether any category marker exists on the registration
- the category itself (A, B, S, N or the older C and D)
- whether the car is recorded as stolen or has outstanding finance
The write-off check shows any insurance write-off record on the registration. The free check covers the public DVLA and MOT record but not write-offs. Where the records hold nothing, that is a result in itself, but it is not proof of a perfect history, so keep inspecting the car and the paperwork.
What to do if the check shows Cat A or Cat B
- Check the registration is the right one. A typo can pull up a different car.
- Compare the VIN. Match the number stamped on the car with the V5C and the history.
- Ask the seller directly where the car has been, who owned it and what the repair history is.
- Walk away if the answers do not hold up. If the seller cannot show paperwork, walk away.
A Cat A or Cat B marker does not mean the car you are viewing is the written-off one. It may mean the identity has been borrowed. That is exactly why matching the VIN, V5C and history matters more than any single label.
Frequently Asked Questions
What does Cat B mean on a car?
Cat B means the car was written off by an insurer under the ABI salvage code and cannot be repaired. The body shell must be crushed, though undamaged parts can be removed and reused. It should never be a car you can drive.
What does Cat A mean on a car?
Cat A means the whole vehicle is to be scrapped and crushed, with no parts reused. It is the most severe write-off category and applies where the car should never go back on the road.
Can a Cat B car go back on the road?
No. The shell is to be destroyed, so the car cannot be repaired and registered again. If a Cat B marker appears on a car that is for sale as a drivable vehicle, it may be a rebuilt shell or a cloned identity, and you should walk away until the paperwork proves otherwise.
What is the difference between Cat A and Cat B?
Both are unrepairable. Cat A means the entire vehicle is crushed with no parts reused, while Cat B means the shell is crushed but undamaged parts (never airbags or seat belts) can be removed and reused. In neither case does the car continue as a road vehicle.
Can you insure a Cat A or Cat B car?
Not to drive on the road. These vehicles should not be on the road at all, and an ordinary motor policy relies on a registered, roadworthy car. If you find a car with this marker, do not buy it until you know exactly what you are looking at.
Is a Cat B car the same as a Cat B breaker?
Yes, in everyday use. "Cat B breaker" just means a Cat B vehicle being sold to a dismantler to be broken up for parts. It is aimed at the trade, not at drivers.
How do I check if a car is Cat A or Cat B?
The free DVLA enquiry does not show write-off categories. Run the registration through a write-off check, which draws on insurer write-off records, and compare the VIN on the car with the V5C and the history before you pay.