Inventories of merchandise, raw materials, supplies, goods-in-process, finished goods and by-products shall be evaluated on the basis of actual cost. Where the cost is higher than the net realizable value, the taxpayer may take the net realizable value as the basis of evaluation. A loss on a decline in the net realizable value of the inventories is allowed to be the cost of goods sold. In case the cost is not ascertainable or the net realizable value is not derivable by reasonable anticipation, the local collection authority-in-charge shall determine it on the basis of expert opinion or by appraisal.
Net realizable value as provided in the preceding paragraph refers to the expected net margin from the sales under regular operation.
Cost as provided in Paragraph 1 may be calculated by using the specific identification method, first-in first-out method, weighted average method, moving average method, or other methods approved by the competent authority in accordance with the categories or characteristics of an inventory.