Only missing 2 weeks so that it enters into force the obligatory nature of the change to electronic billing system and taxpayers that during these last days change to this system may continue issuing them, indefinitely, according to the guidelines of this year. When you switch to the mode of proof prosecutors digital by Internet (CDFI) before 2011 you’ll save additional costs that will have to do next year. If you have not yet changed to electronic billing system you have two options: you can do it next year because it will be required or you can do it once. Doing so next year you will have to pay the allocation of folios and digital stamps that will give services de Administracion Tributaria (SAT) and if you change in what remains of this year avoid you this expenditure, because these requirements are not implemented yet. If you change the mode of electronic billing in this year you’ll be saving you mentioned above and you can follow without the seal and the folio for an indefinite time. If it is necessary to do spending by having the hardware infrastructure and pay the costs of the income from internet, that from now onwards you will have to have always, but the electronic billing system provides great benefits to your company..