Work & employment
Werkvertrag
A Werkvertrag is a contract for work and services under §631 BGB: you owe a finished result, not your working time, and you act as a self-employed contractor. Despite the similar name, it has nothing to do with a Werkstudent employment contract.
Under a Werkvertrag a contractor promises a specific result (a finished website, a translated document, a repaired machine) for an agreed price. Payment is tied to delivery and acceptance of the work, not to hours. The contractor is self-employed: no social-security contributions are withheld, no paid vacation or sick leave exists, and taxes are the contractor's own responsibility.
The name collision with Werkstudent confuses many students. A Werkstudent has an Arbeitsvertrag (employment contract) with employee protections. A Werkvertrag makes you a freelancer for one deliverable. Companies sometimes use Werkverträge to avoid employer duties; if you work fixed hours under instructions with company equipment, that can constitute false self-employment (Scheinselbstständigkeit), which is illegal.
What it means for working students
Occasional freelance gigs on a Werkvertrag are legal for students, including most international students, but income must be declared in a tax return, and non-EU students need to check whether their residence permit allows self-employed activity at all; many student permits do not without separate authorization. When a company offers you a 'working student position' on a Werkvertrag, that is a red flag: you lose minimum wage, sick pay, vacation, and the Werkstudentenprivileg.