In Germany, anyone planning to work as a freelancer in one of the officially recognized “catalog professions” (for example, doctors, architects, lawyers, artists or journalists) must register their activity with the tax authorities. This takes the form of completing a detailed questionnaire - known as the tax registration form - through the federal tax portal. That step ensures you’re properly classified for income tax and social-security contributions from the very start of your freelance career.
What many foreign-trained freelancers find confusing is that this tax-office registration is entirely separate from applying for a trade license at the local business office. If your work falls under a catalog profession, you do not need to visit the trade office or obtain a "Gewerbeschein" - Germany’s standard business license - and you're exempt from paying the local trade tax.
By contrast, self-employed entrepreneurs outside these catalog professions must complete the same tax registration with the finance office and, in addition, file a formal business-license application at their city’s trade office. They also become liable for trade tax. So the key distinction is simple: catalog-profession freelancers register only with the tax authority; all other independent businesses must register both with the tax authority and at the trade office.