Artículo 9. IAS 21 Paragraph 9

The primary economic environment in which an entity operates is normally the one in which it primarily generates and expends cash. An entity considers the following factors in determining its functional currency : (a) the currency: (i) that mainly influences sales prices for goods and services (this will often be the currency in which sales prices for its goods and services are denominated and settled); and (ii) of the country whose competitive forces and regulations mainly determine the sales prices of its goods and services. (b) the currency that mainly influences labour, material and other costs of providing goods or services (this will often be the currency in which such costs are denominated and settled).