개인사업자의 성실신고 개선을 위한 추계방식 및 간편장부의 개선방안

This study investigates how to rationally revise tax laws in order to heighten faithful individual tax report through improving the calculation method of deductible expenses and, as a result, reducing the tax gap. 　Based on the analysis of current tax laws and practices, this study suggests that, first, current year’s revenues, not previous year’s revenues, should be made use of to decide a sole proprietor’s tax report status - that is, whether he/she falls into either the plain estimation method type or the simplified bookkeeping type should be determined on the basis of real substance of his/her business. 　Second, the conditions of applying the estimation method should be materialized so as not to be easily taken advantage of for tax avoidance, and the magnification ratio ceiling, over which the taxable income of a sophisticated estimation method-type sole proprietor is unable to be computed, compared to that of the other-type sole proprietor, should be lowered with the same purpose. 　Third, the penalty tax rate for neglecting bookkeeping should be strengthened to the generally accepting accounting principles type sole proprietors, because much lighter tax disadvantage is unfairly imposed on those larger businesses despite their relatively stronger obligation to be faithful. 　Finally, accounting title in the “simplified book”, adopted for smaller sole proprietors instead of financial statements, should be much broke down to clearly report detailed deductible expenses, and the simpled book itself should be submitted to tax authorities in individual tax report, and adequate tax incentive should be offered to those sole proprietors who keep the simplified book for tax purpose.