Abstract: The Order of the President of the National Agency for Fiscal Administration 139/2020 presents the model, the content and the submission and management procedure for the single return for income tax and social contributions paid by natural persons. By the means of this form, the natural persons declare the income tax and the social contributions for the year 2019, as well as the estimated income tax and social contributions for the year 2020. The single return shall be filled and submitted by the natural persons who, individually or through a form of association, register revenues/losses in Romania and/or abroad and who owe income tax and mandatory social contributions according to the provisions of the Fiscal Code, as well as other natural persons who are not registering revenues, but choose to pay the health insurance contributions. This article presents illustrations regarding the filling of the single return and the taxation mechanism for revenues and social contributions owed by natural persons who register other types of revenues than salary.