투자자-국가분쟁해결(ISDS) 사건에서의 실질과세원칙 - 론스타 및 하노칼 사건을 중심으로

Among the Investor-State Dispute Settlement (ISDS) cases filed against Korea, both the LSF-KEB Holdings SCA and others v. Korea (Lone Star case) and the Hanocal v. Korea (Hanocal case) were arbitration cases under the International Centre for Settlement of Investment Disputes (ICSID), where the issue concerned taxation based on the Substance over Form Doctrine. The claimants, Lone Star and Hanocal, argued that taxation based on this doctrine violated the relevant tax treaties and international investment agreements, and this issue was addressed both in domestic courts and ICSID arbitration. Therefore, this paper examines whether taxation based on the Substance over Form Doctrine violated the tax treaties and international investment agreements. In particular, the paper focuses on the background of the Korean tax authorities’ application of the doctrine, as well as the rulings of domestic courts and the ICSID tribunal on this matter. First, regarding the alleged violation of tax treaties, domestic court rulings consistently found no issue with the tax authorities applying the Substance over Form Doctrine to tax the actual beneficiary, rather than the conduit company established for tax avoidance. The ICSID tribunal in the Lone Star case also ruled that the application of the doctrine did not constitute a violation of the tax treaty. Regarding the violation of international investment agreements, the ICSID tribunal found that the application of the doctrine was neither arbitrary nor discriminatory and did not violate the obligation of full protection and security or the umbrella clause. This ruling was significantly influenced by the legal nature of the Substance over Form Doctrine and its consistent application by domestic courts.