Most countries now tax consumption through VAT instead of old cumulative taxes on goods and services. More recently, the tax in question has been called Goods and Services Tax (GST) because, in analyzing the concept of VAT (Value Added Tax) more closely, one sees that it merely defines a technique of taxation, that is, the noncumulative one, so that reference to the IBS is more appropriate to individualize the non-cumulative tax on goods and services. Modern VAT (or TSG) is a simple, noncumulative tax tribute that focuses on each stage of production and marketing, neutral, and which makes it possible to exempt exports and investments. Considering these positive characteristics and the fact that Pis and Cofins are geared to taxation on consumption, they are proposed to be treated as a real VAT. In order for there to be a non-cumulative effective, however, it is essential to define a good credit criterion, since misconceptions end up dissipating the previously mentioned positive VAT aspects. It appears that the most appropriate concept of credit for a national VAT is that of financial credit, in which the entire amount of tax paid in the previous operation, generates credit, even if not directly linked to the operation that generates the subsequent taxation.