Employment Law2026-10-19

I work part-time and do overtime — from which hour am I entitled to the overtime premium?

Many part-time employees only receive premiums once they pass the full weekly hours of full-timers — and there is usually no sound justification for this. Here is how to calculate your own threshold and secure back payments before the limitation period expires.

You work part-time, but you regularly step in for colleagues, take on extra shifts or stay longer than agreed. None of this shows up on your payslip — the premium for overtime, so the usual explanation goes, only becomes payable once you pass the full weekly hours worked by full-timers, say from 40 hours onwards. That sounds like a fixed rule, but in this form it often no longer is.

In brief

A premium rule that only grants the overtime premium once the full weekly hours for full-timers have been exceeded, and that applies this same threshold unchanged to part-time employees, will as a rule disadvantage them unlawfully. A rigid full-time threshold of this kind breaches section 4(1) of the German Part-Time and Fixed-Term Employment Act (TzBfG) and is to that extent void under section 134 of the German Civil Code (BGB), where no objective reason can be given for it. As a part-time employee, you are instead entitled to a proportionately reduced, individual threshold — how high it lies depends on your contractual hours and the premium rule that applies in your workplace, and it has to be calculated for each individual case.

How I can help you

Reviewing your employment or collective agreement for the applicable premium rule and whether it is valid as applied to part-time employees
Calculating your individual, pro-rata premium threshold
Checking the time limits, so that claims for back payment are not lost to a contractual cut-off period
Asserting the claim in writing against your employer and, where necessary, bringing a claim before the labour court

Why the full-time threshold does not simply apply to you

Section 4(1) TzBfG prohibits treating part-time employees less favourably than comparable full-time employees because they work part-time, unless objective reasons justify the different treatment. For pay and other divisible benefits with monetary value, the provision also expressly requires that these be granted to the part-time employee at least in proportion to the ratio of their working time to full-time working time — the so-called pro rata temporis principle.

A premium rule that only takes effect once the full weekly hours are exceeded hits part-time employees structurally harder: relative to their own working time, they have to put in considerably more additional hours before this fixed threshold is reached at all. What always matters is whether there is an objective reason for this unequal treatment — for instance, protection against health risks from excessive working hours. But a reason of that kind only holds up if the rule actually pursues this aim coherently and does not simply disregard the particular burden placed on part-time employees. Where that is lacking, the rigid full-time threshold cannot be justified as against part-time employees.

The legal consequence: the premium rule is void under section 134 BGB in so far as it applies the unchanged full-time threshold to part-time employees as well. In its place comes a claim to the customary or collectively agreed pay under section 612(2) BGB in conjunction with section 4(1) sentence 2 TzBfG — pro rata, from a correspondingly reduced threshold.

How to calculate your individual threshold

There is no blanket figure that applies to every part-time employee — it depends on the full-time weekly hours and the premium threshold laid down in your contract or collective agreement. The calculation, which can be derived from the pro rata temporis principle in section 4(1) TzBfG, works as follows:

Determine the full-time weekly hours — the regular collectively agreed or contractual weekly working time for full-timers in your workplace.
Determine the premium threshold for full-timers — the number of hours from which full-timers receive the premium under their contract or collective agreement.
Calculate the buffer — the difference between the two figures (premium threshold minus full-time weekly hours).
Calculate the part-time ratio — your contractual weekly hours divided by the full-time weekly hours.
Calculate the pro-rata buffer — the part-time ratio multiplied by the buffer from step 3.
Arrive at your individual threshold — your contractual weekly hours plus the pro-rata buffer from step 5.

An example to illustrate: if the applicable collective agreement provides for full-time weekly working hours of 38.5 but the premium for full-timers only kicks in above 40 hours, this gives a buffer of 1.5 hours. For a part-time employee working 30.8 hours a week, the part-time ratio would be around 80 per cent (30.8 ÷ 38.5). Applied to the buffer, that gives 1.2 hours, so the individual premium threshold would be 32 weekly hours — well below the 40-hour mark that applies to full-timers.

How far this reaches in practice

The issue is not confined to particular sectors: many collective agreements and works agreements contain similar rigid full-time thresholds for overtime premiums, and as applied unchanged to part-time employees these can be legally open to challenge where there is no sound objective reason for the unequal treatment.

An important distinction: the basic pay for every additional hour actually worked is due in any event, regardless of all this — what is in dispute here is solely the additional premium. And this legal question concerns the premium threshold for overtime, not the calculation of holiday pay, which continues to be governed independently by section 11 of the German Federal Leave Act (BUrlG).

The practical trap: cut-off periods

Many collective agreements and employment contracts contain cut-off periods (also called limitation or forfeiture clauses), often set at three months. If the claim is not asserted in writing against the employer within this period, it lapses — regardless of whether it was substantively well founded. According to the case law of the Federal Labour Court, a single written assertion can be sufficient where it makes clear that future claims of the same kind are also meant to be covered. But you should not simply rely on this automatically: whether a single assertion is enough in your case depends on the exact wording of your letter and on the particular cut-off clause. The regular limitation period of three years under section 195 BGB only comes into play once a valid assertion has preserved the cut-off period in any event — anyone who misses the cut-off period never even reaches the question of limitation.

A typical case from practice

A sales assistant works under a part-time contract for 20 weekly hours at a retail business bound by a collective agreement. In weeks when she covers for sickness or holiday absence she regularly works 25 to 28 hours, but is paid only the normal hourly wage for this — the collective agreement only provides for the premium from 40 weekly hours. After reviewing the collective agreement and calculating her individual threshold, it turns out that she is entitled to the premium from around 21 weekly hours. For the months not yet caught by the cut-off period, we assert the back payment in writing with the employer, and in doing so also secure the time limit for any further claims of the same kind.

Common mistakes

Letting the deadline slip. Anyone who only reacts after months has often already missed the frequently three-month cut-off period — even where the claim would be well founded in itself.
Accepting the full-time threshold without question. Many employees assume the collective agreement applies exactly as written, without checking whether the threshold may validly be applied to part-time employees at all.
Complaining only verbally. A conversation with the HR department does not, as a rule, preserve the cut-off period — what usually matters is the written assertion.
Confusing basic pay and premium. The basic wage for additional hours is due regardless of the dispute over the premium; the two should be examined and claimed separately.

If you recognise one of these mistakes in your own situation, or simply do not know whether your premium rule is valid as applied to your part-time work, you should have this clarified now rather than let the deadline keep running — on this and on other questions around pay and working-time disputes I advise you in the area of employment law.

Frequently asked questions

Does this also apply if my employment contract does not refer to any collective agreement at all?

The prohibition of discrimination under section 4(1) TzBfG applies regardless of any collective-agreement binding, to every rule on pay, including individually agreed premium rules or those customary within the business. What is decisive is whether a premium rule exists at all and whether it measures part-time employees against a rigid full-time threshold as compared with full-timers.

What if my employment or collective agreement does not provide for any overtime premium at all?

Then the TzBfG does not conjure up a premium out of nothing. The prohibition of discrimination only ensures that an existing premium rule is not applied to part-time employees in a discriminatory way — if there is no such rule at all, the basic pay for each hour worked remains all that is due.

Do I have to assert my claim afresh in writing every month?

That depends on the wording of your letter of assertion and on the specific cut-off clause. According to the case law of the Federal Labour Court, a single written assertion can be sufficient for follow-on claims of the same kind — but do not rely on this without checking; instead, have your letter drafted so that it is legally watertight.

Does this also affect my holiday entitlement or my holiday pay?

No. The calculation of holiday pay is governed independently by section 11 BUrlG and is not touched by this question of premiums.

How far back can I claim back payments?

That depends first of all on any collectively agreed or contractual cut-off period, which often bites after just three months. If the cut-off period has been preserved by a timely written assertion, the regular limitation period of three years under section 195 BGB applies for the rest.

Your next step

Have your contract and the applicable premium rule reviewed promptly, so that a written assertion can still be made in good time before claims lapse. Arrange an initial consultation for this — the cost of it is governed by the German Lawyers’ Remuneration Act (RVG) or is covered by your legal expenses insurance.

This article provides general information and is no substitute for legal advice in an individual case. Last updated: 2026-10-19.

This article was written by Christian Czirnich, a German Rechtsanwalt (lawyer) since 1994, Kirchseeon (district of Ebersberg). He advises employees, executives and small businesses in employment law, with clients from the district of Ebersberg, east Munich and the Rosenheim area, in English or German and by video on request.

Christian Czirnich, Rechtsanwalt (attorney at law), Kirchseeon near Munich

Describe your part-time hours and your employer's overtime premium rules – I will take a look.

I read every message myself and usually reply on the next working day. What you write to me is covered by legal professional privilege from the first word, even if no engagement comes about. The initial assessment is free of charge.