The Influence of Coretax System Quality on Voluntary Tax Compliance and Enforced Tax Compliance: The Role of Tax Authority Legitimacy as a Mediator and Tax Morale as a Moderator

This study aims to analyze the effect of CoreTax System Quality on Voluntary Tax Compliance and Enforced Tax Compliance among taxpayers in Indonesia, with Tax Authority Legitimacy as a mediating variable and Tax Morale as a moderating variable. Modernization through digital transformation is a critical pillar of tax administration reform, yet its direct impact on compliance remains empirically complex. This research utilizes an explanatory quantitative approach, gathering primary data via digital questionnaires from 96 registered taxpayers using the CoreTax Administration System (CTAS). Structural Equation Modeling - Partial Least Squares (SEM-PLS) was employed for data analysis. The empirical results reveal that CoreTax System Quality has a positive and significant direct effect on Voluntary Tax Compliance and Tax Authority Legitimacy but has no direct significant effect on Enforced Tax Compliance Furthermore, Tax Authority Legitimacy does not mediate the relationship between CoreTax System Quality and Voluntary Tax Compliance because the direct path is already robust. Crucially, Tax Authority Legitimacy fully mediates the relationship between CoreTax System Quality and Enforced Tax Compliance, demonstrating that technology cannot coerce compliance unless it successfully enhances the perceived procedural fairness and legitimacy of the tax institution. Finally, Tax Morale acts as an exceptionally strong psychological amplifier, heavily reinforcing the interaction effect of CoreTax System Quality on both Voluntary Tax Compliance and Enforced Tax Compliance with exceptionally high f-square effect sizes of 0.863 and 0.686, respectively. The findings underscore that digital tax success requires a balanced integration of robust system quality, institutional legitimacy, and the cultivation of taxpayers' intrinsic moral responsibilities.