To change your voicemail code:

1. Call the number 1991 free of charge.
2. Press 3 to change voicemail settings.
3. Then press 2 to access the voicemail code menu.
4. Follow the instructions and enter a new 6- to 8-digit code. For your security, avoid obvious combinations such as 123456 or your birthdate.

Your new code will be activated within a few hours.