Inventory variation (only if there is a decrease in inventory at the end of the year)

To determine the consumption of stocks during the year, it is necessary to determine, in addition to taking into account the purchases made, the stocks not consumed in the year, that is, the variation in stocks. Thus, when the initial stock is greater than the final stock, that is, when there is a decrease in the latter, this variation will be reflected as an expense for the year.

Unlike the above, when the stock at the beginning of the year is less than at the end of it, that is, when there is an increase in stock, it will be reflected as income.

As regards the valuation criteria for stocks , it should be emphasised that the value of the final stocks, which must coincide with the value of the initial stocks for the following year, can be determined by their acquisition price or production cost, with the weighted average cost and FIFO being accepted as valuation criteria for homogeneous groups of stocks.

See within "Computable gross income" the section on " Change in stock " as well as the registration and valuation rule 10 of the General Accounting Plan, approved by Royal Decree 1514/2007, of November 16 (BOE of the 20th), dedicated to the valuation of stock. See also the Resolution of April 14, 2015, of the Institute of Accounting and Auditing of Accounts, which establishes criteria for determining the cost of production.