Many students assume that student assistant contracts (Hilfskraftverträge) are automatically fixed-term. The reality is more nuanced. What matters is the Part-Time and Fixed-Term Employment Act (TzBfG), the practice of the university and the wording of your own contract. This guide explains what the rules allow and where the limits lie.
Kurz beantwortet: The Part-Time and Fixed-Term Employment Act does not impose a general duty to make student assistant contracts fixed-term. A fixed term needs a material reason, or it may run without one for no more than two years (section 14 TzBfG, version of 20 July 2022). In practice many student assistant contracts are fixed-term. The University of Hamburg states a usual minimum term of twelve months for its assistants (as of 29 June 2026).
The most important points at a glance
- The TzBfG requires a reason for every fixed term or allows one without reason for up to two years.
- Whether a student assistant contract must be fixed-term follows from the individual case and the university’s practice, not from a general rule.
- The University of Hamburg generally concludes its contracts for student and research assistants as fixed-term contracts with a minimum term of twelve months.
- Students employed under collective pay rules are, according to the same source, generally employed on open-ended terms. That is a different contract type.
- Check the reason for the fixed term in your contract and ask for it in writing if it is missing.
What does the Part-Time and Fixed-Term Employment Act say?
Under section 14(1) sentence 1 TzBfG, a fixed term of an employment contract is permitted where it is justified by a material reason (gesetze-im-internet.de). The list in sentence 2 gives examples, including only temporary need for the work and a fixed term following a course of study to ease the move into subsequent employment.
The Act therefore does not require a fixed term. It sets the conditions under which a fixed term is lawful. There is a difference between a duty and an option. A university may use a fixed term where it has a reason, but it does not have to do so in every case.
Without a material reason, a fixed term under the calendar is permitted under section 14(2) sentence 1 TzBfG for up to two years. Within that overall period, a fixed term may be extended up to three times. The rule protects employees against long chains without a reason, but for assistant posts it is only one option among several.
How do universities handle assistant contracts?
The practice can be shown using the University of Hamburg. There, student and research assistants receive a fixed-term employment contract, usually with a minimum term of twelve months. Students employed under collective pay rules are, according to the same page, generally employed on open-ended terms (University of Hamburg, information for student employees, as of 29 June 2026).
| Feature | Assistant (SHK or WHK) | Student employee (Studierende Angestellte) |
|---|---|---|
| Contract form (University of Hamburg) | fixed-term, usually a minimum term of twelve months | usually open-ended |
| Hour limit | 20 hours per week; 86 hours per month for SHK and WHK | 20 hours per week for all student employment |
| Holiday | Federal Holiday Act, 20 working days at a five-day week | same entitlements as other collective employees |
The table shows that the job title determines the form of contract. According to the university, an SHK post is fixed-term, while a post as a student employee is usually open-ended. Check which form your offer takes before you think about the term.
Which reasons can justify a fixed term for an assistant post?
For an assistant post, the reasons the legislator lists in section 14(1) sentence 2 may apply. Commonly cited are a temporary need for the work, for example in a limited project, the cover of another person’s work, or funding from budget resources intended for a fixed-term post (nos. 1, 3 and 7). If the reason is disputed, the labour court decides.
If you continue working directly after your studies, you may rely on the reason of follow-on employment after a course of study (section 14(1) sentence 2 no. 2 TzBfG). The move from a Hiwi job into permanent employment is described in the German article on Hilfskraft after graduation.
When does a fixed term become a problem?
A fixed term becomes problematic when no reason holds up, when the contract exceeds its purpose, or when several contracts follow one another. The limits of a chain are described in the German article on chain fixed-term contracts in academia. For the qualification of academic staff, the WissZeitVG sets additional maximum durations (section 2(1) WissZeitVG).
In every case, the reason should be stated in the contract so that the fixed term stays traceable. A contract that only gives a date leaves open on which basis it rests. That gap can later raise questions when an extension or a follow-on contract is at stake.
A worked example of extending a contract
Many assistants extend their contracts several times, so the overall duration matters. Assumption: your first contract runs for twelve months. An extension by another twelve months gives 24 months in total. Without a material reason, the two-year limit is then reached, and any further fixed term needs a reason under section 14(1) TzBfG.
Two further points belong to this calculation. First, within the two-year limit at most three extensions are permitted, not three new contracts. Second, a new contract with another unit of the university may need its own reason. If you do this calculation early, you will know when a conversation with the personnel department is needed.
Ask for an extension in writing. A verbal remark that the contract will carry on is not enough for planning. Ask the personnel department for a supplement or a new contract with the date and the reason for the fixed term.
Frequently asked questions
Must my student assistant contract be fixed-term?
The TzBfG does not impose a general duty to make assistant contracts fixed-term. Many universities nevertheless conclude their contracts as fixed-term agreements. Your contract and your university’s practice show whether this applies to your post.
Can the university fix the term without a reason?
Without a material reason, a fixed term is allowed only for up to two years, and within that overall period at most three extensions. After that, a reason is needed.
What does a minimum term of twelve months mean?
A minimum term sets out how long the contract normally runs. The University of Hamburg states it for its fixed-term assistant contracts. What justifies a shorter term depends on fixed-term law, not on university practice alone.
Can I challenge the fixed term?
You can have a fixed term reviewed in court, but only within the statutory time limit. Seek advice early, for example from a trade union or a legal adviser. The works council of the university is often a first contact on fixed terms as well.
What to do next
- Read the contract and look for the reason for the fixed term or the reference to the legal basis.
- Ask the personnel department which form of contract and which term apply to your post.
- Add up your total time as an assistant if you have already been fixed-term at the university.
- Ask for a written answer if anything is unclear before you sign.
Related articles
- Academic careers: contracts, collective agreements and fixed terms
- Student assistant job in Germany: pay, contract and rules
- Chain fixed-term contracts in German academia
- How many hours may a student assistant work?
Sources: TzBfG, section 14 (gesetze-im-internet.de, last amended 20 July 2022), University of Hamburg, information for student employees (last updated 29 June 2026), WissZeitVG, section 2 (gesetze-im-internet.de, last amended 25 May 2020).
Last updated: November 2026. This guide is general information, not individual advice.
