The Study and Assessment of Factors Affecting on Tax Lags in the Iranian Tax System (A Case Study of Mazandaran Province’s Tax Directorate General)

Abstract This research aims at studying and assessing factors affecting on tax lags in Iran. The statistical population of study consists of 45 active manufacturing companies in the center of Mazandaran province that have filed and submitted their tax returns and related documents during the years 2009 to 2013, and their final taxes have been determined and have reached to the stage of collection. The results indicate that time associated with the tax investigation process and other related processes from issuing final tax sheets to the collection of final tax amounts, is not of any random arrangement. The factors including the accounting books audit or ex- officio assessment, tax finalization processes, differences between  accounting standards and accounting provisions of direct taxes Act, and difference between assessed taxable income and final income and lack of efficient tax culture are effective on tax lags, respectively. According to a time spent mostly on the process of tax collection, firstly it has to do with the taxpayer’s file investigation, the interval between tax return filing and issuance of tax assessment sheets and secondly, it has to do with the period of the finalization of tax case (whereby the tax assessment sheet is served, a possible tax objection is setteled and the final tax sheet is issued). The first factor is related to the complexity of the laws, tax audit of books or ex officio assessment, the differences between accounting standards and and accounting provisions of tax laws as well as the defficiency of the tax audit processes, large volume of tax and audit cases files and the lack of planning and prioritization of tax audit cases. And the second is related to weakness of tax culture and the attitudes and behavior of taxpayers  in addition to the factors mentioned above.