Adoption Determinants of the E-Tax System Among Individual Taxpayers in Surakarta: A Reasoned Action Perspective

Research Objectives: This study aims to test and analyze the empirical influence of taxpayer attitudes, subjective norms, and taxation knowledge on the adoption of the electronic tax system (specifically the newly deployed Coretax system) among individual taxpayers registered at KPP Pratama Surakarta. Design/methodology/approach: This study applies a quantitative explanatory research design grounded in the Theory of Reasoned Action (TRA). The study population comprises individual taxpayers who have accessed the Coretax platform and are officially registered with KPP Pratama Surakarta. A probability sampling technique using simple random sampling was administered, yielding a final usable sample of 100 respondents out of 146 distributed questionnaires. Data collection was carried out through structured questionnaires measured on a 5-point Likert scale. Analytical procedures encompassed instrument quality evaluation (Pearson validity and Cronbach's Alpha reliability), classical assumption diagnostics (Kolmogorov-Smirnov normality, tolerance/VIF multicollinearity, and Rank Spearman heteroscedasticity), and Multiple Linear Regression Analysis using SPSS version 27. Research Findings: The empirical results demonstrate that: (1) Taxpayer attitude has a positive and significant effect on the adoption of the e-tax system (b1 = 0.185; t = 1.766; p = 0.081, significant at α = 10%); (2) Subjective norms have a positive and significant effect on e-tax system adoption (b2 = 0.294; t = 2.872; p = 0.005, significant at α = 1%); and (3) Knowledge has a positive and highly significant effect on e-tax system adoption (b3 = 0.546; t = 4.218; p < 0.001, significant at α = 1%). Simultaneously, attitude, subjective norms, and knowledge exert a significant collective influence on e-tax adoption (F = 31.982; p < 0.001) with an Adjusted R-square value of 0.484 (48.4%), while the remaining 51.6% is explained by extraneous factors outside the structural model. Theoretical/Originality Contribution: This study makes a conceptual contribution by extending the classic Theory of Reasoned Action (TRA) through the inclusion of taxation knowledge as a crucial cognitive prerequisite alongside attitudinal and normative drivers. Originality stems from examining initial empirical behavior toward the nationwide Coretax administration system launched on January 1, 2025, offering timely evidence-based insights for digital tax policy reform in emerging economies.