摘要
債券溢價課稅之問題乃係徵納雙方在債券為溢價購入時，就其溢價部分是否承認得為攤銷進而作為利息所得之減項有所爭議。 成本費用得以扣除之淨所得原則為量能課稅在稅法中的具體展現之一，故本文先演繹歸納稅法中成本、費用之概念內容為何，認為債券溢價部分性質上應屬為獲取債券經濟效益之成本因此得扣除。又在承認成本得以扣除之前提下，因慮及免稅所得所產生之成本費用若得扣除將造成雙重優惠之不公，是以在應稅所得與免稅所得之間尚有成本費用之歸屬問題。而債券投資因其投資型態之不同所產生之投資收益組成型態亦不相同，在「持有至到期日」之投資方式，因投資債券之收益僅生利息所得，不產生任何證券交易所得，故應將溢價成本全數歸於利息所得分攤，此時應以承認溢價攤銷之見解較為合理。 而在「於到期日前出售」之投資方式，此時投資債券之總收益包括利息所得及證券交易所得。本文首先借鏡釋字第493號解釋於股票投資產生應稅所得及免稅所得之成本費用歸屬時所闡釋之分攤原則，再分析債券投資與股票投資性質上之異同以決定該號解釋所闡釋之分攤原則是否可以適用於債券溢價之爭議。經分析後發現債券投資與股票投資最大的差異，即在於因債券具有固定收益之特質故於「出售證券時出售成本之決定」有所不同，亦即債券須依其剩餘之存續期間及未來現金流量折現後之數額為據，有異於股票以原始取得成本為據，是以該號解釋所闡釋之分攤原則於適用上必須有所調整。結論上亦認為承認溢價得為攤銷之見解較合於修正後之釋字493所揭示之分攤原則。 另於「財稅會差異」之主張上，因對於溢價攤銷的否定屬於一種「永久性差異」，且其差異之結果將造成納稅義務人稅捐負擔上之增加，是以該差異之主張須有法律或法律明確授權之命令為之，始合於租稅法律之要求。在稅法第62條文義不明之下，稽徵機關僅依財政部75年函釋為依據並不合於租稅法律主義之要求。 此外，所得稅法第64條第三項，規定債券發行者於折價發行時應為折價攤銷，又債券折價發行乃相對於溢價發行，僅是購買價格相對於票面面額之高或低而已，在會計處理上之觀念及方式相同，僅是效果相反，是以若依所得稅法第64條第三項之規定承認折價發行之折價攤銷亦應承認溢價發行於發行人與投資人間之溢價攤銷處理。而系爭所得稅法第62條與同法第64條第三項之規定併存於所得稅法中，且同規定在「資產估價」之章節裡，是以依照法律之體系解釋，在所得稅法第64條第三項承認折價攤銷下，所得稅法第62條亦應在承認溢折價攤銷下作解釋，是以條文所稱之原利率，應是指「實質利率」而言。 最後，以平等原則之觀點，觀察稽徵機關於零息債券及分割債券之場合的課稅方式。零息債券與分割債券皆屬於「純折價債券」，稽徵機關對此種債券依其解釋函令皆承認在計算利息所得時得為折價攤銷，而債券之折價發行與溢價發行乃為相對，並無本質之不同，是以既承認於折價發行之場合得為折價攤銷，亦應於溢價發行之場合承認溢價攤銷，其見解始為一貫。 綜上討論，本文以為債券溢價課稅應以財務會計上之計算始合於債券之特性，且合於稅法上之成本費用歸屬原則，亦不產生有違反租稅法律主義及平等原則之情事而屬於較為適當之見解。
並列摘要
A controversy about the taxation of bond premiums arises when bonds are purchased at a premium. The competent tax collection authorities and taxpayers have different views on whether the bond premiums can be amortized as deductions of the interest income. The paper intends to explore the controversies using the allocation of costs and expenses principle. Under the current tax laws and regulations, the net income is derived by deducting costs and expenses from the gross income, which is a manifestation of the Ability-to-Pay Principle. The paper first explores the definition of costs and expenses, and argues that the bond premium by its nature should be considered part of the cost to acquire the economic gains of bonds. If the bond premium is deductible from the taxable income and non-taxable income, taxpayers will enjoy the treatment of double tax exemptions, which will violate the fairness principle in taxation. As a result, it is crucial to clarify how to allocate costs and expenses between the taxable income and non-taxable income. In addition, the way taxpayers invest in bonds determines the type of payments they will receive. Held-to-maturity bonds only incur interest income, without gains derived from the securities transactions. Therefore, in the case of held-to-maturity bonds, the total cost of bond premium should be allocated to the interest income. Consequently, the view that the bond premium should be amortized is more reasonable. With regard to bonds sold before maturity, the bonds will incur interest income and gains derived from the securities transactions. The paper first examines the J.Y. Interpretation NO.493, which promulgates the principle about how to allocate the costs and expenses between the taxable income and non-taxable income derived from stock investments. It moves on to compare the similarities and differences between bond investments and stock investments to see if the allocation principle of stock investments is applicable to bond premiums. The greatest difference between bond investments and stock investments is that bonds as fixed-income securities have different costs from those of stock investments. In other words, the cost of a bond is the sum of the present value of its future cash payments between the transaction date and the maturity date while the cost of a stock is its history cost. Given the difference between bond investments and stock investments, it is necessary to make adjustments to the allocation principle of stock investments before applying to it to bond investments. In conclusion, the interpretation that bond premiums should be amortized complies with the allocation principle promulgated by the J.Y. Interpretation NO.493. The paper concludes that it is reasonable to amortize the bond premium in the taxation of bond investments.