납세자 권익 보호를 위한 납부불성실가산세의 개선방안 연구

Additional tax on insincere payment is levied when a taxpayer doesn't pay national tax by deadline. Additional tax system is instituted for the purpose of assuring faithful fulfillment of cooperative duties on taxpayer provided by the tax law. Although the system of additional tax on insincere payment is admissible, unreasonably excessive burden on taxpayer violates proportional principle. Additional tax operates as a serious threat to the taxpayer's property rights and it should not be abused or excessively applied. The legal nature of additional tax on insincere payment is administrative sanction, but the essence is that taxpayers pay interest on delinquent taxes. Imposing additional tax on insincere payment applying a high interest rate of 10.95% in spite of a decline in the market interest rate is unduly disadvantageous to taxpayers. The current interest rate of additional payment on national tax refund is only 1.6%. Additional tax on insincere payment should be improved for the direction of lowering interest rate which is too high compared with that of additional payment on national tax refund. Furthermore, it is difficult to eradicate tax evasion just by imposing a heavy penalty on the taxpayer. Thus, it is necessary to establish upper limit of additional tax on insincere payment and to increase incentives for taxpayer's self-rectifying actions such as amended tax return or tax return after due date.