Deborah

Deborah S.Sos., LL.M., Int. Tax., BKP., BKBC., APCIT

Deborah is a leading tax practitioner specializing in strategic business restructuring, corporate funding, and securitization. With extensive experience in tax consultation and dispute resolution, she has successfully advised multinational corporations and state-owned enterprises.

She holds a Bachelor’s Degree in Fiscal Administration from the University of Indonesia (Cum Laude) and an LL.M. in International Taxation from Wirtschaftsuniversität Wien (WU, Vienna). Certified as a Tax Consultant (USKP A, B, C) and a Licensed Tax and Customs Attorney, Deborah has a robust legal and technical foundation in international taxation.

Committed to staying ahead of global tax trends, she has recently attended advanced training at IBFD, including:

• Post-BEPS Holding, Finance, and IP Companies in International Tax Structuring (2023)
• PE Risks and Opportunities in International Tax Structuring in the Post-BEPS Era (2023)
• The OECD Pillar 2: Focus on the Globe Rules (2023)
• Substance Requirements in Post-BEPS International Tax Planning (2024)
• Beneficial Ownership and Related Controversies (2024)

Her research contributions include “The Legal Relevance of the OECD Standard” in Exchange of Information for Tax Purposes (Linde, 2013). She is also a frequent speaker at IKPI, IAI, Bank Indonesia, Toyota, and other corporate institutions, sharing insights on international tax policies, transfer pricing, and tax dispute resolution.

Deborah continues to shape Indonesia’s tax landscape through high-stakes advisory, litigation, and policy advocacy, ensuring strategic compliance with evolving global tax regulations.

• Recently, Deborah successfully led a high-profile national project, overseeing the merger of a leading aviation service provider in Indonesia through book value restructuring. This complex transaction was executed with exceptional precision, ensuring full compliance with Indonesian tax regulations while maximizing efficiency for all stakeholders involved. The successful completion of this project underscores her profound expertise in corporate tax structuring and strategic mergers, reinforcing her reputation as a key figure in Indonesia’s tax landscape.
• In 2024, Deborah achieved another significant milestone by successfully handling the tax facility application for a mineral mining company with an investment value of approximately USD 600 million. This complex and high-value project required in-depth expertise in Indonesian tax regulations, investment incentives, and fiscal policies to secure optimal benefits for the client. Through strategic planning and meticulous execution, Deborah navigated the regulatory landscape, ensuring full compliance while maximizing the available tax incentives. Her ability to align corporate investment strategies with Indonesia’s tax framework played a crucial role in securing the approval, ultimately supporting the company’s expansion and long-term sustainability. This accomplishment further solidifies Deborah’s reputation as a leading tax expert in corporate structuring, fiscal incentives, and high-value investment projects, reinforcing her standing as a trusted advisor for multinational corporations and industry leaders in Indonesia.
• In 2024, Deborah successfully managed a tax audit for a chemical industry company, a case of particular significance due to the company’s related-party transactions, which have become a frequent point of contention in Indonesia’s tax landscape. Understanding the sensitivity and complexity of such audits, Deborah employed a strategic and diplomatic approach, ensuring transparent communication between the taxpayer and the Directorate General of Taxes (DGT). As a tax consultant, she recognized the importance of acting as a bridge between tax authorities and taxpayers, facilitating mutual understanding and compliance while safeguarding her client’s interests. By leveraging her deep knowledge of transfer pricing principles, comprehensive documentation, and strong analytical skills, she effectively elaborated evidentiary support, addressing the tax authority’s concerns with clarity and precision. Her ability to present structured and well substantiated arguments led to the successful resolution of the audit without dispute, minimizing financial and reputational risks for the company. This achievement further underscores Deborah’s reputation as a trusted advisor in tax audits and compliance, particularly in cases involving related-party transactions and transfer pricing matters. Her success in ensuring a smooth and dispute-free audit process reflects her expertise, professionalism, and commitment to fostering a balanced and constructive relationship between tax authorities and corporate taxpayers in Indonesia.

• In 2024, Deborah achieved a landmark victory in tax litigation, successfully defending one of Indonesia’s largest textile companies in VAT disputes. This case was particularly challenging due to the complexities surrounding VAT regulations and industry-specific tax treatments. Leveraging her deep expertise in tax law and courtroom strategy, Deborah meticulously built a strong evidentiary foundation, effectively demonstrating her client’s compliance with prevailing tax regulations. Her ability to present compelling legal arguments, substantiate financial data, and counter the opposing claims with precision played a pivotal role in securing a favourable ruling. Through strategic litigation and expert advocacy, Deborah not only safeguarded her client from significant financial exposure but also reinforced legal clarity on VAT treatments in the textile sector. This victory further cements her reputation as a tax litigator, known for her exceptional courtroom performance, mastery of tax dispute resolution, and ability to secure successful outcomes for major corporations.

• In 2024, Deborah successfully handled SP2DK for a leading property company in Indonesia, ensuring a smooth resolution with the tax authorities. SP2DK is a letter issued by the Head of the Tax Service Office to request an explanation of the data and/or information from the Taxpayer. Given the scrutiny on the real estate sector and the increasing focus on tax compliance, this case required a meticulous approach to substantiating financial records and tax positions. With her deep understanding of Indonesia’s tax regulations and strong negotiation skills, Deborah effectively presented clear and well documented justifications to the Directorate General of Taxes (DGT). Through strategic communication and structured evidentiary support, she was able to demonstrate the company’s compliance, ultimately convincing the tax authorities to close the SP2DK without further disputes. This achievement highlights Deborah’s proficiency in tax compliance and regulatory negotiations, further reinforcing her reputation as a trusted advisor who ensures efficient resolutions while maintaining strong relationships between taxpayers and the tax authorities.

• Business model optimisation
• Cross-border project management
• Policy design
• Technology services

• Agriculture
• Aviation
• Automotive
• Banking
• Construction and materials
• Consumer goods and services
• Energy
• Financial services
• Fisheries and aquaculture
• Food and beverage
• Forestry
• Government and public policy
• Healthcare
• Industrials
• Insurance
• Investment management
• Mining
• Oil and gas
• Pharmaceutical and life sciences
• Real estate
• Shipping
• Social infrastructure
• Technology and telecommunications
• Transport

• Master’s Degree in International Taxation (LL.M), Wirtschaftsuniversitat, Wien (WU, Vienna) 2013
• Bachelor’s Degree in Fiscal Administration (Cumlaude), University of Indonesia 2009

• The Indonesian Tax Consultant Association (IKPI) 2011

• Certificates A, B, and C (all completed) Indonesian Tax Consultant Examination 2013