Mergers, consolidations, acquisitions, and spin-offs are increasingly popular legal actions undertaken by companies as business strategies to expand their scope and enhance competitiveness more rapidly than organic growth. When executing these actions, businesses face legal complexities involving various aspects such as corporate law, contract law, competition law, and capital market law. To investigate these legal complexities, the author completed a four-month internship at the law firm Armand Yapsunto Muharmsyah & Partners. This report primarily focuses on examining company compliance with Law No. 5 of 1999 concerning the Prohibition of Monopolistic Practices and Unfair Business Competition, as well as the legal due diligence process as a comprehensive examination of a company's legal aspects, including deeds, licenses, assets, and case status. The report concludes that the company under study has conducted the acquisition process in accordance with internal and external compliance corridors. Internal compliance was achieved through legal due diligence activities to ensure the target company had no legal issues. In terms of external compliance, the company fulfilled its obligation to notify KPPU about the merger and acquisition.