Temporality of the taxable in respect of tax value-added considerations previous: not intended to present work, become a Studio background of the legislation that establishes and regulates the temporality of the taxable in respect of value added tax; It constitutes in itself a little more graphic and condensed representation that guides so that the reader is placed in a simple manner within the legal context. Should be noted that the legislator homeland, in the opinion of the undersigned, puts aside the reality of the way in which they operate the majority of SME s in terms of their commercial relations covered in commercial customs, which makes it difficult in many cases to determine the moment in the tax obligation, what arises making reservation, is clear, from the originated by issuing the commercial invoice. No you can put aside the myriad of imprecision, vagueness and ambiguity that abound in the country legislation which regulates the matter, and of which much has been said and written, is imperative to make mention to the term authorization of payment order issue that determines, according to our rules, the emergence of the tax obligation, in negotiations with the State authorities. Timing refers to the moment in which means happened taxable and therefore born the tax liability. Four large generators of the fact taxable VAT are recognized in our legislation in general terms, these are, the alienation of personal property, the provision of services (including the services from abroad), the definitive import of movable property and movable property and exports services, this activity upon which rests the tax 1However it should be noted that the law makes a second distinction, and will referred to the budget that defines the emergence of the tax obligation in relation to the organ or entity perceptor of the good or service, so there is a differentiation as soon as if the perceptor of the good or service entity is a public body, or If it is a private entity, in the first case, the problem, to a despite the inaccuracies of the norm, is of less relevance in relationship clear is, to the topic that concerns us, namely the determination of the moment is born the tax obligation, without considering the implications, economic, fiscal, or strict legal nature as well as the exceptions, and the reason is that the standard defines in principle a unique moment for the birth of the obligation, namely: the authorization of the payment order, is so manifest in Art. .