Abstract: This article presents a series of theoretical and practical matters regarding the input and output method in/from the VAT upon collection system. The input in this system of a taxable person whose place of business is in Romania can be performed anytime during the financial year, from a tax period to another tax period, and not only in January or on the registration date for tax purposes. The output from the system can be performed by submitting the notification at the tax body until the 20th, inclusively, of the month following the tax period in which the taxable person has exceeded the ceiling provided in Article 282 Paragraph (3) of the Fiscal Code. The notification is sent to the tax body from the 1st to the 20th of each month, if the output is optional. This can be done by the online submittal of the form 097 or 700. The VAT upon collection system cannot be optionally waived in the first year in which the application was opted for.