This is terrible advice, and simply wrong. I lived and worked in Germany as a self employed person with primarily one client for 2.5 years - along the way I properly maintained my business and taxes in a good and legal standing. I am not an accountant or a lawyer, and this is not professional advice. What the commenter here is referring to is a specific situation called "Scheinselbstständigkeit" which roughly translates to "fake/sham self employment". If you work as a contractor for just one company for a long time the tax office can audit and determine you're really an employee. This is not a simple decision however and many factors go in to it. Also, the decision is made by your regional tax office and they each have their own standards. In Hamburg for example, I was told it wouldn't even be a question until 4 years time. Even then there are a lot of additional circumstances which must be taken into account. Ideally the self employed would form a German LLC, (GmbH) and make themselves an employee of the company. The best advice, as always, is to speak with a locally certified professional! and not strangers on the internet.