The observation that people can earn money by doing nothing constitutes a challenge in tax law in general and in tax treaty law in particular. This article aims to crystallize the notion of income from omissions. The article first shows that a distinction may be made not only between different types of income (active versus passive income) but also, along the same lines, between different types of omissions. The specific problems that arise under tax treaty law are thus subject to completely different rules. The article shows this for both omissions in connection with passive investments and omissions of a human activity.