Law Number 24 of 2009 on National Flag, Language, Emblem, and Anthem of Indonesia requires that any contract involving an Indonesian party must be drafted in Indonesian. In applying this law, the Supreme Court of the Republic of Indonesia, in Nine AM v. PT Bangun Karya Pratama Lestari judgment, annulled a loan agreement because it was considered to violate the language requirement. Although claiming to strengthen the use of Indonesian language in a contract, this judgment underscores a potential risk of voidance a foreign party face in entering into an agreement drafted in a foreign language when contracting with an Indonesian counterparty. On the other side of the hemisphere, the Court of Justice of the European Union in Anton Las v. PSA Antwerp NV and New Valmar BVBA v. Global Pharmacies Partner Health Srl drew the public attention to the obligation to use Dutch in employment contract and company documents as imposed in the Dutch-speaking region of Belgium. Despite Indonesia and Belgium being geographically far from each other, the abovementioned judgments underline the phenomenon that national language still plays an important role in influencing cross-border legal relations. This article seeks to explore the legal impacts of the obligation to use national language in contracts has on freedom of parties to contracting. It further argues that this obligation impedes international contracting.

中文翻译：

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印度尼西亚和比利时强制使用本国语言：国际合同的障碍？

2009 年关于印度尼西亚国旗、语言、国徽和国歌的第 24 号法律规定，涉及印度尼西亚一方的任何合同必须以印度尼西亚语起草。在适用该法律时，印度尼西亚共和国最高法院在“上午九点”诉 PT Bangun Karya Pratama Lestari 案的判决中宣布一项贷款协议无效，因为该协议被认为违反了语言要求。尽管声称在合同中加强了印度尼西亚语的使用，但该判决强调了外国当事人在与印度尼西亚对手方签订合同时以外语起草协议时面临的潜在无效风险。在半球的另一边，欧盟法院在 Anton Las v. PSA Antwerp NV 和 New Valmar BVBA v. Global Pharmacies Partner Health Srl 提请公众注意比利时荷兰语区规定的在雇佣合同和公司文件中使用荷兰语的义务。尽管印度尼西亚和比利时在地理上相距甚远，但上述判决凸显了民族语言在影响跨境法律关系方面仍然发挥着重要作用的现象。本文旨在探讨在合同中使用本国语言的义务对当事人缔约自由的法律影响。它进一步争辩说，这项义务妨碍了国际订约。上述判决凸显了民族语言在影响跨境法律关系方面仍发挥重要作用的现象。本文旨在探讨在合同中使用本国语言的义务对当事人缔约自由的法律影响。它进一步争辩说，这项义务妨碍了国际订约。上述判决凸显了民族语言在影响跨境法律关系方面仍发挥重要作用的现象。本文旨在探讨在合同中使用本国语言的义务对当事人缔约自由的法律影响。它进一步争辩说，这项义务妨碍了国际订约。