Short Answer
You must provide exactly two weeks' notice on physical paper to resign during your trial period.
Digital messages, emails, or scans are completely invalid under German law and will prolong your employment.
What Most Expats Don't Realize
You sent a polite resignation email to your manager on the 15th of the month to leave by the end of the month. Two weeks later, HR told you that your email had no legal standing and demanded you stay for another two weeks until a physical letter arrived. You missed the start date of your next job, resulting in a contract breach and a €1,800 penalty.
What To Do
- Print your resignation letter on physical paper and sign it using a blue or black wet-ink pen.
- Hand the physical letter directly to your HR manager or send it via registered mail (Einschreiben) with tracking.
- "Bitte bestätigen Sie den Erhalt dieser schriftlichen Kündigung." (Please confirm the receipt of this written resignation.) — ask your manager to sign a copy of the letter acknowledging delivery.
The Truth
Quitting during the trial period is not seen as a "failure" in Germany. It is respected as a rational, decisive career move if the "match" isn't perfect.