German phrase
Entschuldigung, ich habe mich vertan.
Meaning
Sorry, I was mistaken
When to use it
A polite admission of error. It often accompanies a factual correction in formal settings.
Example dialogue
Entschuldigung, ich habe mich vertan. Die Abgabe ist am Montag, nicht am Mittwoch.
I'm sorry, I was mistaken. The submission is on Monday, not Wednesday.
Alles klar, danke.
All right, thank you.