It is a Federal tax on the import of foreign products that takes place at their entry in national territory. Its taxpayer is the importer or whoever is established by relevant legislation, the seller of seized or abandoned products. The Executive Branch may, under the conditions and within the limits established by law, modify the rates or the bases for calculating the tax, in order to adjust it to the country’s foreign trade and exchange rate policy objectives. See Arts. 19 to 22 of the National Tax Code.