This means the code has been used by another account.
If you encounter technical issues, Cornelsen provides specific support channels: cornelsen.de codes
Instead of searching through a massive database, entering a code at cornelsen.de/codes takes you exactly where you need to be. What Content Can You Unlock? This means the code has been used by another account
For the 10 million people (students, parents, and frustrated grandparents) who handle these codes every year, here is the unspoken rulebook: here is the unspoken rulebook: