海外期貨交易損失的跨期扣除──評最高行政法院108年度大字第3號裁定

The Inter-Period Deduction for Loss on Overseas Future Trading: Comments on Decision Year 2019 Da No. 3 of the Supreme Administrative Court

有關個人的海外期貨交易損失得否跨期扣除，最高行政法院108年度大字第3號裁定認為，有關損失的扣除，原則上應限於當年度產生的損失為準，跨年度的損失扣除須有法律明文規定；同時認為所得基本稅額條例第12條規定，應屬立法者「明示其一、排除其他」的立法例，因而否定海外期貨交易損失得以跨期扣除。
對此，本文將從「期間課稅原則」的體系定位出發，並參考德國聯邦憲法法院關於限制損失跨期扣除的合憲化事由，進而探討「體系正義」在本案的適用，以及「反面推論」在本案的容許性；此外，本文亦將指出，有關海外查核的現實困境問題，實屬稽徵程序該如何改進的議題，與「客觀淨值原則」的實踐無關；又「補償性課稅」的思維，亦違反「法治國原則」。

Regarding whether the inter-period deduction is applicable to loss on personal overseas future trading, Decision Year 2019 Da No. 3 of the Supreme Administrative Court considers that the deduction for loss shall be based on the loss of the current year in general and the inter-period loss deduction shall have regulations specified in laws. In addition, the legislation of Article 12 of the Income Basic Tax Act shall be an example of “one is expressed and others are excluded”; therefore the inter-period deduction for loss on overseas future trading shall be denied.
Focusing on this, the study starts from the positioning of “the principle of period taxation” and refers to the constitutionality concerning the limitation on inter-period deduction for loss provided by the German Federal Constitutional Court for the application of “system justice” in this case, and the admissibility of “reverse inference”. In addition, the study also highlights the dilemma of overseas audits in reality, which is actually an issue of how to improve audit procedures and is irrelevant with the fulfillment of “objective net worth principle”. Meanwhile, the concept of “compensative taxation” also violates “the rule of law”.