This study aims to evaluate the effect of computerized tax services in improving tax performance by moderating governance principles in Jordanian tax income departments. The study is based on a questionnaire distributed to income tax auditors, who were chosen by the simple random sampling method, so that 170 questionnaires were subjected to statistical analysis. The study models were formulated in the form of simple and multiple regression equations to test the hypotheses of the study, in addition to relying on One Sample T-test to calculate the mean of questionnaire answers. The most prominent research results is that the application of tax governance principles through the provision of computerized tax services is reflected in the increase in confidence between taxpayers and income tax departments, the efficiency of tax performance, and tax proceeds. Also, the study pointed out the importance of the income tax departments to prepare strategic plans regarding the development and the follow-up of modern technologies related to computerized tax services. It especially regards linking and collecting tax from taxpayers such as via electronic tax payment and collection system, in order to ensure the speed of completion, accuracy of calculation, and raising the efficiency of tax performance.

Abstract
1. Introduction
    1.1. Problem of the Study
    1.2. Study Contribution
2. Literature Review
3. Methodology
    3.1. Study Population and Sample
    3.2. The Instrument of the Study
    3.3. Statistical Methods Used in Data Analysis
4. Results
    4.1. Statistical Analysis and Hypothesis Testing ofthe Study
    4.2. Statistical Results of One Sample T-Test
    4.3. Hypothesis Testing
5. Conclusion
References

• Sanaa Nazami MASWADEH(Department, School of Business, Jadara University, Irbid, Jordan) Corresponding Author
• Tariq Samih HANANDEH(Economics and Muamalat Administration, University Sains Islam Malaysia. Irbid, Jordan.)