稅法是成文法,從事稅法工作就是從事解釋成文法工作。惟法院在解釋稅法時,往往不見得會依原文字義解釋,而會進一步從案例事實做出「補充」,因而產生與稅法交織一起的「司法原則」(Judicial Doctrine)。這些司法原則往往影響後續實務判例及發展。本文將探討影響美國稅法領域甚鉅的五大「司法原則」:「實質重於形式原則」(Substance-Over-Form Doctrine)、「經濟實質原則」(Economic Substance Doctrine)、「商業目的原則」(Business Purpose Doctrine)、「騙局原則」(Sham Doctrine)、「步驟交易原則」(Step Transaction Doctrine) 對稅務實務之影響。並依序以United States v. Phellis(1920);Helvering v. Gregory(1934);Pinellas Ice & Cold Storage Co. v. Commissione(1932);Cortland Specialty Co. v. Commissioner(1932);Kirchman v. Commissioner(1989);Minnesota Tea Co. v. Helevering(1938);Commissioner v. Gordon(1968);King Enterprises, Inc. v. United States(1969);Kuper v. Commissioner (1976)等案例作為討論標的。
Tax law is statutory law. The practice of tax law is the practice of statutory law interpretation. However, courts may not always interpret the law literally. Courts have, in many instances, interpreted and applied the law with developed judicial doctrines. Thus, judicial doctrines have played an important role in resolving tax controversies.This article discusses judicial doctrines (substance-over-form doctrine, economic substance doctrine, business purpose doctrine, sham doctrine, step transaction doctrine) that impact on tax practice.