The Austrian Minimum Taxation Act (Mindestbesteuerungsgesetz - MinBestG) aims to ensure a minimum tax level of 15 % for multinational groups with annual revenues of at least EUR 750 million. The minimum tax level as such is measured at a jurisdictional level. Regarding the jurisdictional computation of the effective tax rate, the allocation of profits/losses and taxes under the MinBestG is largely based on the distribution of taxing rights for business profits under tax treaties and the underlying PE concept. However, the relationship between tax treaties and the MinBestG is put to the test when income generated through a business may be taxed in the source state in deviation from the PE principle. This is particularly relevant with respect to cross-border income from immovable property covered by Art 6 OECD MC.