If you fall ill as an employee in Germany, you have two separate legal duties: notify your employer immediately on the first day, and have the incapacity medically certified — by day four at the latest, or from day one if your employer requires it. Since January 2023 the certificate travels electronically for statutorily insured employees (the eAU), but the notification duty is unchanged — and in our practice it is that duty, not the certificate, that gets employees into trouble with warnings and withheld pay.
Duty one: immediate notification (Anzeigepflicht)
Under § 5(1) EFZG you must inform your employer of your incapacity for work and its expected duration „without undue delay” (unverzüglich). In practice this means:
- On the first day of illness, before or at the start of your working time where possible — not at midday, not the next day.
- By the fastest available channel — phone, email or messenger, addressed to the right recipient (line manager or HR, depending on your contract and company practice).
- With a duration forecast — a good-faith estimate („probably out until Friday”) is sufficient.
You are not obliged to disclose the diagnosis: the employer learns only that you are unfit and for how long. The diagnosis appears solely in the data sent to your health insurance fund.
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Notify before your shift starts
Call or email your manager (and HR, if required) before your normal start time on day one, stating that you are unfit and for roughly how long. Keep a copy.
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See a doctor in time
By day four at the latest — or day one if your contract requires it. The practice transmits the eAU electronically; ask for the patient printout anyway.
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Update if it lasts longer
If you will be out longer, obtain a seamless follow-up certificate and notify your employer again — the duty applies to every extension.
Duty two: medical certification (the AU)
The statutory default: day four
If the illness lasts longer than three calendar days, your incapacity must be medically determined no later than the following working day (§ 5(1) EFZG). Calendar days count: fall ill on Friday and the three days run Friday to Sunday — certification is due Monday.
The day-one exception
Your employer may require the certificate from the very first day — and, per Federal Labor Court case law, needs no particular reason. Day-one clauses in contracts and company policies are common and generally enforceable, and the instruction can also be issued to a single employee individually. Where such a rule applies, certifying on day four is itself a breach of duty.
The electronic AU (eAU) since 2023
For employees with statutory health insurance, the paper chain was replaced in January 2023:
- The doctor determines your incapacity and transmits the data electronically to your health insurance fund.
- Your employer retrieves the eAU data from the fund — you no longer hand in the certificate yourself.
- Your duty has shifted from „submitting” to „having the incapacity determined” in time (§ 5(1a) EFZG); the deadlines are unchanged.
You still receive a paper printout for your own records — keep it. Electronic transmission does fail, and the printout proves you fulfilled your duty on time; a failed retrieval is then a problem between employer and fund, not yours.
Where paper still rules
The eAU does not cover everyone. You still need — and must actively submit — a paper certificate if you are privately insured, if the certificate comes from a doctor abroad or a purely private practice, and in a few niche cases such as minijobs in private households. The day-four (or day-one) deadline applies identically; only the delivery route is old-fashioned.
Follow-up certificates and duration updates
The initial certificate carries a forecast end date. If you are still unfit when it expires, you need a follow-up determination (Folgebescheinigung) — issued on the last certified day or the next working day, with no gap. Gaps create two risks: uncertified days may be treated as unexcused absence, and beyond six weeks of illness they can interrupt your Krankengeld. You must also notify the employer again for each extension — the eAU does not do this for you.
Falling ill abroad
If you fall ill while abroad, the rules tighten (§ 5(2) EFZG):
- Notify your employer by the fastest possible means — phone or email — of the incapacity, its expected duration and your address abroad. The employer bears the communication costs.
- If statutorily insured, additionally notify your health insurance fund.
- Obtain a certificate from a local doctor. EU certificates generally carry the same evidential value, provided they document actual incapacity for work rather than a mere illness.
- Notify employer and fund again when you return.
Certified sick days during vacation are not deducted from your vacation entitlement — see falling sick during vacation.
What happens if you get it wrong
Violating these duties does not, as such, destroy your continued-pay entitlement — but it has real consequences:
- Abmahnung: late or missing notification is the classic subject of a formal warning — see what an Abmahnung means. Repeated violations after a warning can support a behavioural dismissal, even where the illness was genuine.
- Withheld pay (§ 7 EFZG): the employer may refuse continued payment as long as you fail to present the required certificate — or, under the eAU, fail to have the incapacity determined. The amounts must be paid once you deliver, but the temporary freeze is lawful.
- Evidential-value attacks: a certificate obtained late, or covering a suspiciously convenient period, invites a challenge to its evidential value in court.
Sickness during the notice period
Being on sick leave does not prevent dismissal in Germany, and a dismissal does not end your sick-pay rights — the six-week entitlement runs on, at most until the employment ends. Two points from our practice:
- In several recent decisions the Federal Labor Court has held that a certificate covering precisely the period between notice and last working day can have its evidential value „shaken” — the employee must then prove the illness otherwise, typically through the treating doctor.
- Conversely, where the employer dismisses because of the illness (Anlasskündigung), the continued-pay obligation can survive beyond the termination date (§ 8 EFZG) — a frequently overlooked rule worth real money.
If you were dismissed while off sick, the dismissal itself is often challengeable — see termination while on sick leave — and the three-week deadline for a Kündigungsschutzklage runs regardless of your illness.
Worked example
Software developer in Düsseldorf, statutorily insured, gross €5,400 per month (net about €3,300). Her contract requires a certificate from day one. She wakes with severe flu on a Tuesday.
- 07:45 Tuesday: she emails her team lead and HR — unfit for work, expects to return Monday. Duty one fulfilled.
- Tuesday morning: video consultation; the practice determines incapacity until Friday and transmits the eAU. She saves the patient printout. Duty two fulfilled.
- Friday: not recovered. She obtains a follow-up determination the same day (no gap) and messages her team lead again.
A colleague handled the same flu differently: no message on day one („HR sees the eAU anyway”), doctor only on day three. The employer issued an Abmahnung and froze €890 of salary until the determination was in place — both, on these facts, defensible. The eAU did not protect him: the notification duty was his alone, and the day-one clause applied.
Frequently asked questions
Do I have to answer work calls or emails while on sick leave?
As a rule, no. Sick leave suspends your duty to work, including routine availability. Narrow exceptions exist for urgent matters only you can answer — a password, a key handover detail — and these should stay brief.
Can my employer ask what illness I have?
No. Neither the eAU data set nor the employer’s copy of a paper certificate contains a diagnosis, and you are not obliged to volunteer one. Such questions may simply be declined.
My employer says the eAU never arrived. Is that my problem?
Not if you did your part — notified on day one and had the incapacity determined in time. Show the patient printout and refer the employer to your health fund. Pay withheld despite proof must be released.
Can I leave the house, shop or travel while on sick leave?
You may do anything that does not hinder recovery — which depends on the illness. With a broken finger, a supermarket run is unobjectionable; with severe influenza, a weekend trip invites trouble. Behave consistently with your illness.
I am privately insured — what changes?
The eAU does not apply to you: you receive a paper certificate and must deliver it yourself within the day-four (or contractual day-one) deadline. Everything else applies identically.