Reasons for the Gap between Declared and Assessed Taxable Incomes of Non Manufacturing Companies Listed on Tehran Stock Exchange

The taxable income of legal persons is a critical issue in Iran as this sector plays a dynamic role in economic, social, and cultural activities in the society. The major problem of this study is the gap between the amounts of taxable income calculated by taxpayers and the Tax Administration. Field and bibliography methods besides Pearson Correlation Test were used, and all four hypotheses of research were confirmed. Accordingly, the reasons for the difference or gap between declared taxable income and assessed taxable income include breach of direct tax law by taxpayers, violation of accounting standards by taxpayers, lack of sufficient evidence and documents (including expenses, tax exemptions, and tax incentives) in the hand of taxpayers, ignorance of tax directives, instructions, and regulations by taxpayers.