What is it and when to act?
The Sozialversicherungsnummer (RVNR) is a 12-character identifier that records your pension, health and unemployment insurance contributions. It is issued automatically when you start your first job in Germany and stays with you for life. Keep the Sozialversicherungsausweis like an important document.
Common mistake
I threw away the Sozialversicherungsausweis as 'unnecessary paper'. Three years later I needed the number for Elterngeld (parental benefit). Had to request a duplicate and wait three weeks. The card is small — I now keep it in my passport.