This study is highly motivated by the recently adjusted rate of the daily presumed income on businesses is the cause of the dispute between the business community and the Ethiopian Revenue and Customs Authority (ERCA). The main goal of introducing the presumptive tax system is to provide tax payers with equitable, efficient, quality services and bringing more firms to the tax net by promoting tax payers to voluntarily discharge their tax obligations.However, when the daily presumed income is estimated the question of fairness and just arisen that led the authority and the business to dispute. The authority claims that the turnover declared by the category “C” businesses is “understated” while the businesses argue that the presumed daily income by the authority is “overstated”. Hence, the researcher is highly interested to study the implementation process of the estimation of the daily income that caused the dispute. In studying the implementation process the case of other African countries will also be reviewed so that Ethiopia can learn from these countries in the region.