It is October and you have a job offer: 25 hours a week at a startup, decent pay, the kind of role that looks good on a CV. You are about to say yes when an older student stops you in the kitchen. "Twenty hours," she says. "Go over twenty during the semester and you stop being a student for insurance, and your Krankenkasse bill triples." You did not know that was a thing. It is very much a thing.
German student work rules are a small maze of three separate limits that interact: a yearly day limit tied to your visa, a weekly hour limit tied to your health insurance, and a monthly earnings limit tied to your tax. Get them straight once and you can work confidently. Get them wrong and it costs money or, worse, your permit extension.
The 120-day rule (your visa limit)
Non-EU students on a German study residence permit may work 120 full days or 240 half days per calendar year without asking the immigration office for anything. This is written into the residence permit itself.
The definitions matter:
- A full day is any work shift longer than 4 hours.
- A half day is a shift of up to 4 hours.
- The clock resets every calendar year (1 January), not your enrolment anniversary.
So you could work 120 long shifts, or 240 short ones, or any mix. EU, EEA, and Swiss students ignore all of this, they have no day limit and work under the same rules as Germans.
If you want to work more than 120 days, you need approval from the local Ausländerbehörde (immigration office), and it is discretionary. They are more likely to say yes in semester breaks than during lectures.
The 20-hour rule (your insurance limit)
This is the one that ambushes people. Separate from the visa day count, there is a weekly hour limit that decides whether you keep cheap student health insurance.
Work up to 20 hours per week during the semester and you stay in the student bracket: reduced or student-rate health insurance, and you are treated primarily as a student. Go over 20 hours during lecture periods and the system reclassifies you as primarily an employee, which means full social contributions and the loss of student insurance rates. Your monthly Krankenkasse cost can jump from around €130 (student rate) to a percentage of your full salary.
The exception: semester breaks (Vorlesungsfreie Zeit). During official breaks you can work more than 20 hours a week without losing student status, because you are not in lectures. Many students stack full-time work into the breaks for this reason.
What a Werkstudent contract changes
A Werkstudent (working student) contract is the format most students should aim for, because it is built around these rules.
| Feature | Werkstudent | Regular part-time |
|---|---|---|
| Max hours in semester | 20/week | counts against 120 days fast |
| Counts against 120-day visa limit | Usually no (semester hours) | Yes |
| Health insurance | Student rate kept | Risk of losing it over 20h |
| Pension contribution | Yes (small, refundable later) | Yes |
| Pay level | Often higher, role-related | Varies |
Werkstudent hours during the semester are generally excluded from the 120-day count because they fall under the working-student privilege (Werkstudentenprivileg). In the breaks, a Werkstudent can also work full time. The role is often related to your field, which is the other reason it beats stacking café shifts: it builds the CV you came for.
The money: minijob, tax, and the €556 line
Three earnings thresholds shape what lands in your account.
Minijob (up to €556 per month, 2025). Below this line your income is tax-free and you pay no income tax. The employer covers a flat contribution. You can opt out of the small pension contribution, though staying in is usually wiser. This is the simplest setup and what most café and retail student jobs use.
Above €556 (Midijob and normal employment). Wage tax (Lohnsteuer) and social contributions get withheld from your pay. This feels like a loss, but it usually is not permanent.
The annual tax-free allowance. In 2025 the Grundfreibetrag is €12,096. If your total yearly income stays under it, you owe no income tax for the year, which most students do. The wage tax withheld from your monthly pay then comes back when you file an income tax return (Einkommensteuererklärung) the following year. Filing as a student is straightforward and the refund is often several hundred euros.
How the three limits interact
The mistake is treating these as one rule. They are three, and you have to satisfy all of them at once.
Picture a non-EU student working a 19-hour-per-week Werkstudent job during the semester, earning €900 a month. Visa: fine, Werkstudent semester hours sit outside the 120-day count. Insurance: fine, under 20 hours keeps the student rate. Tax: above €556, so Lohnsteuer is withheld, but the year's total is under €12,096, so it gets refunded. All three boxes ticked.
Now picture the same student bumping to 22 hours a week during lectures. Visa: still arguable, but insurance breaks, over 20 hours costs the student rate, and the Krankenkasse bill climbs. One hour either side of the line changes the maths.
What to do this week
- Ask the employer in writing whether the contract is a minijob, Werkstudent, or normal part-time, the label decides your tax and insurance treatment.
- Track your work days in a calendar from 1 January if you are non-EU, so you never blow past 120 by accident.
- Keep your weekly hours at or under 20 during lecture periods unless you have confirmed in writing that you keep student insurance.
