The issue of transfer pricing in extractive industries, including the coal sector, has gained global attention. To mitigate the risks of inappropriate transactions and tax evasion, resource-rich countries incorporated, among others, the arm’s length principle into their legislation. Some countries use the “sixth method”, which mandates quoted prices for affiliated transactions. Indonesia’s Government Regulation No. 15 of 2022 introduces a similar approach for coal pricing, albeit with a certain hierarchical aspect. This article explores the Indonesian “sixth method” for intercompany coal sales and its interaction with existing transfer pricing rules, including potential issues that may lead to disputes.