The Legal Position of Marketplaces as Intermediaries in Consumer Disputes

The expansion of digital marketplaces has transformed consumer transactions from a bilateral seller consumer relationship into a multi actor platform ecosystem. This development raises a central legal question: when a consumer suffers loss, is the marketplace merely an intermediary, or can it bear legal responsibility alongside the merchant? This study analyzes the legal position and liability boundaries of marketplaces in Indonesian consumer disputes. It employs normative legal research using statutory, conceptual, case, and comparative approaches, focusing on Law No. 8 of 1999, Government Regulation No. 80 of 2019, Minister of Trade Regulation No. 19 of 2026, Constitutional Court Decision No. 86/PUU XXIV/2026, and comparative developments under the European Union Digital Services Act. The study finds that a marketplace is not a legally neutral conduit: it is a Electronic Commerce System Provider (PPMSE) business actor that controls transaction architecture, verification, labels, rankings, payment interfaces, and complaint mechanisms. Nevertheless, liability should not automatically be joint and several for every merchant violation. This article proposes a functional proportional liability model in which liability escalates according to control, knowledge, due diligence, causal contribution, and the platform's role in creating consumer reliance.