The obligatory nature of electronic invoicing for the year 2011 as provided for in the system of tax administration (SAT), for those taxpayers with annual revenues equal to or greater than 4 billion pesos, sees 300 as potential customers. You may think that the companies that realize the software for electronic invoicing shall be subject to only those taxpayers with this type of income, so it could have less income, the reality is different. Taxpayers with incomes equal to or greater than 4 million pesos, only 5 per cent of the total number of taxpayers, but among them are 80% of total national turnover. Companies that are willing to pay for these software are mature businesses and undertake the adoption of technology to become fully automatic. Moving to electronic billing system greatly enhances the profile of the company because it makes it more productive, efficient and technological. As well as taxpayers would improve, the software companies increase your income, so in the end all win. If you as a taxpayer have to switch to electronic billing system, we recommend is mandatory until next year but you do it once, because you will save money on digital stamps that will be needed later.