On April 15th, 2020, the Finance Ministries of Germany and Austria concluded a competent authority agreement on the tax treatment of the wages of cross-border workers and frontier workers. This agreement is intended to clarify the interpretation of Art 15 para 1 and 6 of the tax treaty between Germany and Austria in cases of home office and short-time work during the COVID-19 pandemic. Michael Lang takes a critical look at the content of this competent authority agreement, which obviously violates tax treaty law.