In this work, the behavior of leuco solutions of VAT dye was studied by using their spectrophotometeric data. Initially, the leuco solutions of C.I.VAT Green 1 were prepared with different concentration of sodium hydrosulfite and soda. Then, the absorbance spectral of leuco solutions were measured by spectrophotometer. The relationship between color and absorbance of leuco solution and concentration of soda and sodium hydrosulfite was studied. The obtained result shows, that the color and absorbance of leuco solution depend on the amount of soda and sodium hydrosulfite. Beside, the reduction properties of sodium hydrosulfite depend on the concentration of soda. Subsequently, the leuco solution was simulated by using subtractive color mixing low.

Tax refund is one of the most critical areas in the implementation of the VAT Act. There is typically variance between the taxpayer’ s claimed credits and the tax auditor’ s assessment leading to tension between the two parties, and if it isn’ t managed properly, it will weaken the operation of VAT system and will provide the examination prorogation, inequity and distrust in the law and the law enforcement. On the other hand, taxpayers may embezzle large quantities of revenue from government’ s revenues through forgery, book washing and understatement and thus, make an imbalance in the government funding calculations. Therefore, since the introduction of VAT Act and its implementation is new, a practicable solution need to be devised. In this line through interviews with collegiate and professional experts, the main factors and problems involved in such challenges are relatively extracted where a lavshe test, and a Cronbach’ s alpha test were used to confirm the validity and reliability of research instruments. The questionnaires were distributed among experts and taxpayers of Tehran and Qom provinces and upon gathering the data, by using SPSS software, certain descriptional and inferential tests were administered at the level of each component in question. The results indicate that based on tax experts’ opinions, there are 3 main challanges namely, “ lack of suitable IT infrastructure” , “ lack of tendency in tax officials for making tax refund” and “ lack of stong law enforcement sanctions” respectively. From the taxpayers’ point of view, there are 3 challenges ahead of tax refund, namely “ lack of sufficient tax and accounting knowledge” , lack of suitable IT infrastructure, “ lack of tendency in tax officials for making tax refund” . Furthermore, there is no significant diference between tax experts’ and taxpayers’ opinions regarding the tax refund challanges.

It is quite sometime now that the design and implementation of a VAT has turned into a debate in the pubic finance in Iran. But, as it has always been, the impact of a VAT on inequality is a major concern in making a decision for its implementation. This paper, using the analytical method, intends to make an estimate of the possible impact of a VAT on inequality in Iran on the basis of the five suggested possible scenarios. Using the selected model and national input-output table, it tries to calculate the share of present indirect taxes or future VAT in the prices of the goods and services in each scenario. The results are then compared with household consumption, using the ISIC classifications. By estimating the Engle Curve for each consumed item in the household budget, the cost of the VAT implementation for each ten brackets of the of the household is then calculated. Putting the resulting figures in two groups of distributional and tax system equity indicators, reveals the regressively of the tax in all five scenarios. However, measuring the importance of the impact it could be safely concluded that the inequality variable in Iran would not be significantly affected by the implementation of a VAT.

One of the most important problems and challenges of the VAT system is formation of paper companies which lacks credit and incurring great financial losses for the country’ s tax system. The paper companies have no existence and no economic activities and make disorder in economy of the country and they prevent economic transparency. The main objective of the present study is to identify the factors shaping the formation of paper companies and its relation to the risk of value added tax auditing: this research is descriptive survey and its type is correlation, and the structural equation model is used for analysis. In this way, data collection inventories are used for paper companies, un-real selling and auditing risk. The statistical community of this study is the managers and experts, and companies called for the first stage of registration of the VAT registration system in Tehran. The findings indicate that the effect of paper companies on VAT auditing risk is significant and the graph in the standard mode also shows that VAT auditing risk is 82 percent and we can trace paper companies at 97% of the forefront of dubious transactions. Therefore managers can reduce the risk of VAT auditing by designing appropriate conditions and improve paper companies’ identification.