Risk assessment takes many factors into consideration. Location, driver age, driver claims history, occupation, to name but a few. Some types of vehicles have a higher incidence of theft than others, thus have a higher theft loading factor. Some areas have higher density, and higher reports of accidents, thus higher accident loading factors. And so on.
The final premium is the culmination of many factors, and one cannot always isolate one factor as the driving force behind the premium.
Also, the NCB is what it says, a No Claim Bonus. It is not a No Fault Bonus. One needs to remember that it costs the insurer, in time and resources, even if it’s minor damage, to process a claim. You are being rewarded, through the NCB process, for not costing the insurer in resources and labour.
Fault/liability is determined through a recovery of damages process, and this process brings with it a legal concept (in SA Law, that is) called subrogation. The insurer, by contract, and as a result of paying the claim, steps into the shoes of the insured and holds liable, or attempts to hold liable, the other party, sometimes called the third party, for the damages as a result of the accident. Often there is no one party 100% at fault, and there will be apportionment.
Nonetheless, in cases where there is a full recovery, or as close as full recovery can ever be, the insured will be in a position to receive back his deductible/excess/first amount payable, and in some cases, his NCB can be reinstated.
However, the reinstatement of the NCB is not a foregone conclusion, and the decision varies from company to company. As I said before, it costs money to process a claim, even if there is a full recovery, and the NCB is merely an incentive not to claim.
NCB’s are an effective means of premium reduction when small claims are at issue such as superficial body panel damage. One should never, however, decide to protect one’s NCB when serious damage has taken place which could affect the safety of the vehicle. This is just plain unwise, and not worth the risk.
Also, do not make the mistake of accumulating damage in the hopes of getting it all repaired in one go, and only paying one excess. Most policies are issued on the basis of an excess per incident, and loss adjusters can easily pick up old damage.
Ultimately, one needs to weigh up a number of factors and then decide what is the best course of action.