Two DDTC Professionals Discuss Turnover Taxes in Austria

RUST, DDTCNews – The Institute for Austrian and International Tax Law and the Vienna University of Economics and Business had once again hosted their annual tax conference, the Rust Conference, in Austria.

This year, the annual tax conference, held from 2 July to 4 July 2026, was themed Turnover Taxes (including VAT/GST and Digital Service Taxes) in the Light of Treaty Law.

At the conference, two DDTC professionals, namely Senior Specialist of DDTC Consulting, Dawud Abdul Qohhar Lubis, and Specialist of DDTC Fiscal Research & Advisory, Abiyoga Sidhi Wiyanto, were selected to present an update on regulations concerning the application of gross turnover-based taxes (turnover taxes) in Indonesia within the framework of international tax treaties.

This Rust Conference served as a forum for the exchange of ideas and stimulating discussions from various countries on turnover taxes. Notably, this year's conference was attended by 67 participants from 34 countries.

The conference was opened by Prof. Michael Lang of the Vienna University of Economics and Business (WU Vienna), Austria. Several prominent professionals were also in attendance, including Yariv Brauner, Jeffrey Owens, Alexander Rust, Claus Staringer, Pasquale Pistone, Rita Szudoczky, Richard Stern, Georg Kofler and Raffaele Petruzzi.

The conference also opened with a Doctorate Workshop, which served as a forum for doctoral candidates to present their research. This was followed by 4 sessions each day, with each panellist or national reporter setting out the regulations and practices in their respective countries.

Both DDTC professionals were entrusted with delivering a presentation and input statement relating to Session 4 on the second day, which examined the policy outlook on gross turnover-based taxation in Indonesia.

For information, prior to Abiyoga and Dawud, a number of DDTC professionals regularly participated in the Rust Conference over the years. The following is a list of DDTC professionals who have attended the conference from year to year:

• Senior Partner of DDTC Fiscal Research & Advisory, B. Bawono Kristiaji, participant at the Rust Conference 2016 themed Improving Tax Compliance in a Globalized World,
• Senior Partner of DDTC Fiscal Research & Advisory, B. Bawono Kristiaji, and Senior Manager of DDTC Fiscal Research & Advisory, Denny Vissaro, national reporters for the Rust Conference 2017 themed Implementing Key BEPS Actions: Where do We Stand?,
• Partner of DDTC Consulting, Ganda Christian Tobing, national reporter for the Rust Conference 2018 themed Tax Treaty Arbitration,
• Partner of DDTC Consulting, Yusuf Wangko Ngantung, national reporter for the Rust Conference 2019 themed Controlled Foreign Company Legislation,
• Senior Partner of DDTC Consulting, Romi Irawan, national reporter for the Rust Conference 2021 themed Mandatory Disclosure Rules (MDR), and
• Senior Manager of DDTC Consulting, Riyhan Juli Asyir, and Assistant Manager of DDTC Consulting, Atika Ritmelina Marhani, national reporters for the Rust Conference 2022 themed Mobility of Work. (rig)

*This article is a report by Senior Specialist of DDTC Consulting Dawud A. Q Lubis and Specialist of DDTC Fiscal Research & Advisory Abiyoga S. Wiyanto.