所得稅法新制對債券流通市場之影響

96年所得稅法修訂前，存在著前手息稅款爭議、買賣說與融資說爭議以及折溢價攤銷等債券利息所得課稅問題。新修稅法將個人之債券利息所得改採分離課稅、法人則採合併申報，並賦予後手代扣前手稅款之權，同時新修稅法亦納入34號公報之有效利率概念，考慮了折溢價攤銷的會計實務，有效地解決舊制存在多年之課徵問題與爭議。新制稅法施行後，國稅局可順利以徵得全期稅款，並降低稅負之不確定性，債市得以健全發展。然對納稅義務人而言，則是利弊互見，影響最深者乃承作債券附買回之個人及信託利益不作分配之投信基金，被代扣附條件交易利息之10％稅款後，其實質報酬僅為舊制之九成；而承作債券附買回業務之債券自營商，其稅負成本轉變為票面利率計算之稅款與RP利率計算之稅款差異數，且RP期間已無抵稅權，故建立養券部位時票面利率宜列為重要參考依據，同時養券之資金來源亦應朝多元發展；此外，營利事業在考量溢折價攤銷而改以有效利率計算稅負成本，其實質報酬反較舊制增加。

關鍵字

債券附條件交易；所得稅法新制；折溢價攤銷；前手息；買賣說；融資說

並列摘要

Before the Income Tax Law was amended in 2007, there existed some controversial issues for the following issues: previous trader taxes, Outright Trading Method Financing Method and Amortizations. All these problems are related to the interest income tax treatment of the bonds. The new tax law has adopted separate taxation for the individual interest income of the bonds and combined taxation for the corporation, respectively. It also provides the tax payers the privilege of withholding taxes for previous traders. In addition, the new law includes No. 34 bulletin’s effective tax rate concept and considers the practical accounting of amortization, and in effect, found the solutions for all the recurring tax-imposing problems and controversies from the old days. After the new law has taken effect, the National Tax Administration will successfully receive all of the revenues and decrease the uncertainty of tax rate. The debit market will go through a period of stable development. However, for the tax payers, there are both advantages and disadvantages. The biggest change will be funds that transact RP for individuals and trusts but do not distribute incomes. after deducting 10% of trading interest with certain conditions, whose net benefit will be as low as the 90% of that of the old law. In the meantime, to the bond merchants of transacting in RP, their tax cost will be transformed into the differences between the taxation based on coupon interest rate and the taxation based on RP interest rate. Moreover, there is no tax waiving during the RP period. As such, it would be necessary to set up the coupon interest rate when holding bonds as an important criterion for reference. In the meantime, the funding resources have to be developed diversely. Moreover, when considering amortization and turning to adopt the effective interest rate to calculate the taxation cost, the net benefit will be much increased than that in the old system.