In this article you will read about the fundamental principles of costing 1. Cost is related to its cause. A cost is related as closely as possible to its cause. Rent of the factory, for instance, cannot be charged to office expenses, repairing charges of a machine cannot be charged to some other machine, and in the same way, a foreman’s salary cannot be charged to one single unit, if many more units are produced in a department supervised by that foreman. The reason in all the above cases is that cost is related to its cause. 2. Cost is charged after it is incurred. If a cost is not incurred either actually or notionally, it cannot be charged to a cost centre. For instance, a cost unit is not charged with selling costs while it is still under manufacture in the factory, as selling costs would occur only when the cost unit is finished in the factory and is sold. Similarly, normal loss or wastage is to be borne by the units of which it is a loss or wastage, su