Because of no comprehensive research in this area, the aim of this research is identifying all Tax compliance factors for the first time, using the OECD Tax compliance model (2004). Using explorative studies and regarding the Iranian environmental conditions, this study categorizes the factors into 8 components and 40 indexes; then it analyzes opinions of 61 experts about the indexes effects on Tax compliance, by implementation of Fuzzy Delphi Method. The results show that all factors have impact on Tax compliance in exception of the Taxpayer type, Taxpayer’ s revenue type, Taxpayer’ s occupation, Taxpayer’ s age, Taxpayer’ s gender, Taxpayer’ s religion, Taxpayer’ s race and nationality, ethnicity backgrounds, establishing Tax advisers, social norms, and civil organizations.

Background: Mental accounting attempts to explain the mechanism by which people code, group, and evaluate economic income. The purpose of this study is to explain mental accounting with Tax compliance, Tax evasion and Tax ethics in the implementation of Tax System smartness. Method: The present research was among mixed researches. Delphi technique was used in the qualitative part. The community of experts was in the field of Tax affairs, and 20 experts were identified by non-probability and judgmental sampling method, and finally 13 of them declared their readiness to cooperate. The tool was interview and the data was analyzed with Delphi technique. In the quantitative part, the survey method has been used. The community of employees of the Tax affairs department of Tehran were in the field of accounting, and 285 people were selected as a statistical sample and completed the questionnaire. The collected data were analyzed by structural equation modeling and PLS software. Results: The results showed that there is a significant relationship between income Tax and Tax compliance, Tax evasion and Tax ethics in the implementation of Tax System smartness. Also, there is a significant relationship between value-added Tax and Tax knowledge, and Tax compliance, Tax evasion and Tax ethics in the implementation of Tax System smartness. From a point of view, there is a significant relationship between Tax thinking and Tax compliance, Tax evasion and Tax ethics in the implementation of Tax System smartness. Conclusion: It is hoped that the results of this study will help the planners and policy makers in this area in order to make the Tax System of our country more intelligent.

This study aimed to explain mental accounting with Tax attitudes in smartening the Tax System in 2022. This qualitative and survey study used the Delphi method to identify the optimal situation, examine the current situation and then explain the mental accounting model with Tax attitudes in smartening the Tax System by a cross-sample questionnaire. In this research, the chain sampling method was used in the Delphi section. In the first round of Delphi, 20 experts were identified, and finally, 13 declared their readiness to cooperate in providing expert opinions. The size of the statistical sample was calculated using Cochran's formula, which includes the employees of the Tax Affairs Department of Tehran in the field of accounting, and 285 people were selected as a statistical sample. After distributing the questionnaire to the statistical sample, the collected data was analyzed using PLS software. The results showed a significant relationship between income Tax and Tax knowledge, religiosity, patriotism, and the perception of the transparency of Tax reports in smartening the Tax System. In addition, there was a significant relationship between value-added Tax and Tax knowledge, religiosity, patriotism, and perception of the transparency of Tax reports in smartening the Tax System. There was a significant relationship between Tax thinking and Tax knowledge, religiosity, patriotism, and the perception of the transparency of Tax reports in smartening the Tax System. The results will help planners and policymakers make Iran's Tax System more intelligent.

Tax income is the most important source of income for government after the oil income in Iran. The Tax System, however, suffers from two factors: long lags, and inflexibility. In this paper, we investigate the efficiency in the Iranian Tax System with respect to the two factors above using cointegration analysis for period 1982:3-2002:4. The results indicate that in the long run there is a twenty-two-month lag in Tax collection, and, 9-18 month lag in short term. Since the Tax System is not flexible enough in response to price changes, this time lag in Tax collection along with inflation has led to a decline in real income Tax.

The Tax System as a subset of the economic System serves the purposes that the economic System pursues. On the one hand, the goals of each System are based on the assumptions and values of each school, and therefore the fundamental function of Tax Systems cannot be more discrete than the underlying issues. The Tax System of the Islamic Republic of Iran has witnessed changes in Tax structures in recent years. A better understanding of the nature of the Islamic Tax System and its functions may help to formulate and shape a more Islamic Tax System. This paper examines the functions of a favorable Islamic Tax System in comparison with the functions of the conventional economic Tax System, using the content analysis approach, and therefore proposes some considerations for value added Tax. This article uses the content analysis method of the functions of the favorable Islamic Tax System in comparison with the functions of the Tax System of the conventional economy and then, based on it, points about substituting the tawazon criterion in Islamic economic justice, Tax principles, Tax rates and bases, and share of Taxes in government revenue sources. According to the Islamic policymaker, who considers justice as the basis of organizing society, Taxes are also a tool for this purpose, and Taxes that are compatible with achieving economic balance are considered appropriate. The balance criterion is considered in all the initial, process and final stages and the increase of Tax revenues is followed by using justice-oriented methods and Tax revenues can never be increased at the expense of justice. Also because in the economic System. Islam has part of the resources of wealth production (Anfal) at the disposal of the government.

The existence of petrol revenues as a Sources of government revenues in Iran has caused to a malfunction in Tax System and then the lag getting of Tax revenues by government. Therefore, inflation is the diminishing factor of the value of real Tax revenue through lags duration. In this research the efficiency of Tax System concerning Tanzi theory is considered. More than lags calling to account, the price elasticity of demand have been calculated and this elasticity is lower than one that confirm Tanzi theory based on “if Tax System to be inflexibility and long lag in collection are seen, real Tax revenue decreases”. Studying data are used quarterly (1: 1369-3: 1389) in this research. The calculated average of Tax lags in prepared essay is 15 months. So, not only inflation has increased, but also the real Tax revenue is instrumental in its decreasing. Concerning the deduction of real Tax revenue as the result of inflation, budget deficit increases as well.

A model of Islamic Taxes is developed in this study and then the performance of present Iranian corporate Tax System is tested against it. The estimated income Tax elasticity, results and analysis of variance of corporate Taxes in alternative groups show that present Taxing practices are at variance with the Islamic Tax model implications. The results are obtained from a survey of 10108 corporate Tax files submitted to the Tax Department in the year 1373 (1994). To obtain Tax efficiency and equity, which are the goals of the Islamic Tax model, a new System of corporate Taxing were proposed to be adopted, given that the government’s Tax income would not decline. The simulation results of the new System show that both higher efficiency and equity standards are obtained and government income Tax receipts are not curtailed.

Iran’s Tax System indicators, such as lower ratio of Taxes to GDP and funding resources, Tax pressure on companies in direct Tax bases and focus on import tariffs in indirect Tax bases, indicate that the structure of Tax System in Iran is not desirable. Comparison between corporate Tax and income Tax that the latter includes all income in economy, indicates an imbalance, injustice and inefficiency in collecting Taxes on income, and shows that economic agents, despite companies, do not pay Taxes proportional to their income. In the case of indirect Tax, there is not a general consumption or sale Taxes, and what exist under this title, just include excise Taxes and very limited kind of VAT.To improve Iran's Tax System, in this paper, we provide structural reforms as follow: we first introduce two new Tax bases, in this area the environmental and local Taxes are provided, the second reform is to improve the performance of the available Tax bases, include direct and indirect Taxes, in this area two Tax bases include global income Tax and VAT are presented. Finally, in respect to implementing policies related to economic evolution project, especially in the energy sector, essential Tax policies for saving energy are provided.

The most important goal of a Tax System is to increase Tax compliance level. There is a clear and exact definition of Tax compliance in the developed Tax Systems, while this concept is an unknown area in Iranian Tax System. In Iranian Tax texts, compliance is doing one's Tax obligations according to the law. This definition is vague. The current paper has three main goals: a) studying different meanings of Tax compliance in Iranian Tax law, b) selection of a clear and precise definition of Tax compliance and c) estimation of Tax compliance rate and its obstacles in Iranian Tax System. Our research method is based on library research method. The results indicate that Tax compliance rate in Iran has increased from 18.8 percent to 49 percent between 2002 and 2009.

Iran’ s economy has been always under pressure to provide resources for public spending and it is limited by a Tax System that causes disruption in the behavior of economic agents; therefore, it is expected that the country’ s Tax System can be improved via inspiring by the global Tax reforms. The opponents argue that the lack of comprehensive Tax information System, low administrative capacity of the Tax Agency and Taxpayers, and different economic structure of Iran make such reforms impossible in Iran. But it must be emphasized that Iran’ s economy will face three major challenges in the field of social security, reduced Tax revenues from international trade and competitiveness in the near future. Therefore, expanding the Tax bases and lowering the Tax rates is necessary in dealing with these challenges, and this is possible through the comprehensive income Tax System. The main objective of this study is to investigate and compare the comprehensive income Tax System and its adjusted versions with the Tax System in Iran. The results show that the Iran’ s Tax System is very complex and violates the principles and objectives of Tax reform in many cases. Furthermore, high Tax burden on companies, high rates of social security, and widespread Tax evasion in the self-employed section are among the features of the Iranian Tax System which apart it from other common Tax Systems in the world. In order to reform the Tax System in Iran, the best method is fundamental reforms based on the comprehensive income Tax System, if it is not possible for any reason (the lack of prerequisites or political consensus), we can do some adjustments (reform in a scientific framework based on Tax expenditures and economic interests; simplifying the Tax System; bias correction in providing corporate finance method and mitigating double Taxation; threshold for exemption based on relative poverty; adjustment of Tax threshold, depreciation, and interest deductions for inflation; change of executive System from Tax-based structure to functional basis structure; improvement of Tax justice perception; change the Tax unit from the individual to the family; providing Tax System without having to provide Tax returns from Taxpayers) to improve the existing System.