Cat A, B, C, D, S, N Really Mean Could Save You Thousands? UK Car Write-Off Categories Explained If you are looking for a  second-hand car in the UK , you may have noticed advertisements describing vehicles as  Cat S  or  Cat N . You may also have heard of  Cat A  and  Cat B , although you are very unlikely to see these cars being offered as normal used vehicles. These letters are not simply grades showing whether a car is “good” or “bad”. They are  insurance write-off categories  that tell you what happened to a vehicle after it was damaged and, most importantly, whether the vehicle can legally return to the road. Follow Car Guru DIY Blog The UK currently uses four main insurance salvage categories:  A, B, S and N . Categories A and B are for vehicles that must not return to the road, while categories S and N describe vehicles that can potentially be repaired and used again. The Association of British Insurers (ABI) describes the...