The purpose of this research is to examine the factors that influence the application of the electronic tax filing system (e-filing) of taxes in the order of adaptation of policies by the developing government wherein Indonesia relies on a self-assessment system (SAS) which implements voluntary compliance by taxpayers. Using the theory of planned behavior, the technology acceptance model (TAM) as a theoretical basis, this study looks at the effects of taxpayer compliance (TC), perceived usefulness of function (PU), taxpayer satisfaction (US), and taxpayer behavior (BI) in Indonesia in single study. This study is cross-sectional and correlational. Data were collected through a questionnaire survey of 298 taxpayers. Data were analyzed using Statistical Package for Social Sciences. This study is cross-sectional and correlational. Data collected through a questionnaire survey of 298 taxpayers. Data were analyzed using Statistical Package for Social Sciences. The results show that taxpayer satisfaction, perceived usefulness of taxpayers functions, and behavior contribute to tax compliance by 25.25%, that taxpayer satisfaction and taxpayer behavior are significant predictors of tax compliance and taxpayer behavior strengthens the moderating relationship between taxpayer satisfaction and tax compliance. At the same time, the perception of the usefulness of the function does not have a significant value on tax compliance. Given that this study was cross-sectional, monitoring changes in behavior over time was not possible. The results are helpful for policymakers and taxpayers in Indonesia. To the researchers knowledge, this is the first study to examine the contribution of perceived usefulness of function, taxpayer satisfaction, and taxpayer behavior of taxpayer compliance.